WEST OF ENGLAND RAPID TRANSIT · 2019. 6. 9. · The proposed BRT network consists of a number of...

WEST OF ENGLAND RAPID TRANSIT

Technology Review

Appendices

September 2008

Prepared for: Prepared by:

West of England Partnership Office Wilder House Wilder Street Bristol BS2 8PH

Steer Davies Gleave 28-32 Upper Ground London SE1 9PD +44 (0)20 7919 8500 www.steerdaviesgleave.com

Technology Review

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Contents

APPENDICES

A CLIENT BRIEF

B HYBRID ULTRA LIGHT TRANSIT SYSTEM (HULTS) REPORT

C DESIGN REQUIREMENTS FOR STREET TRACK, OFFICE OF THE RAIL REGULATOR, MAY 2008

Technology Review


Appendix

APPENDIX A

CLIENT BRIEF

1

Bus Rapid Transit May 2008

Assessment of Ultra Light Rail Technology: Brief for Consultants

Introduction

The four councils are progressing plans for the next route in a Bus Rapid Transit (BRT)network to serve the West of England sub-region. It is intended to undertake route-basedpublic and stakeholder consultation on the first phase of the proposed Ashton Vale toEmerson’s Green BRT route, from Ashton Vale to Temple Meads, in May/June 2008, priorto submission of a major scheme business case to the Department for Transport inAutumn 2008. BRT is identified in the South West’s regional funding programme currentlyto a total of £71 million.

An initial appraisal of technology options was undertaken in 2007. This appraisalconcluded that a form of bus based rapid transit was the appropriate technology for theproposed rapid transit network in the sub-region. This appraisal took in to account materialcollected and provided about the Ultra Light Rail technology. Since then the Ultra LightRail organisation has continued to ask the West of England partnership and otherstakeholders to revisit the technology appraisal.

Key Issues

The proposed BRT network consists of a number of cross sub-region routes. The first ofthese is included in the Bath Package (BRT Line 1). BRT Line 2 is proposed to run fromAshton Vale to Emerson’s Green via Bristol City Centre with the first phase, Ashton Vale toCity Centre (Temple Meads) the subject of the next major scheme bid in 2008. Emerson’sGreen to Bristol City Centre and Line 3, Hengrove to North Fringe will subsequently follow.The choice of technology needs to meet the needs of Line 2, Ashton Vale to City Centre(Temple Meads) but also the wider network.

The aim of BRT was set out in the Greater Bristol Strategic Study (GBSTS) as “to providehigh quality alternatives to the private car”.

It also provided the following objectives:

• to extend choice of transport modes for all, in particular for private car drivers toencourage a shift to public transport;

• to promote sustainable development by providing high quality public transport links;

• to improve access to public transport areas that currently have poor provision;

• to improve integration of the public transport network;

• to promote social inclusion by improving access to employment, retail, community,leisure and educational facilities; and

• to improve safety along the corridor by providing a high quality public transportalternative to the private car.

In addition to these objectives, the project to date has been using more specific successcriteria to assess the scheme as it develops. These are:

• Mode Shift from car.

• Help reduce traffic congestion.

• Contribute towards economic growth.

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• Deliver an affordable network.

There are also a series of local considerations. These include:

• Low emission technology.

• Ability to accommodate services fro further afield across the sub-region (i.e widerthan the Bristol urban area).

• Retention of appropriate road network capacity, particularly on the inner ring road inBristol City Centre.

• System needs to be complementary and able to be integrated with the network ofShowcase bus corridors and Greater Bristol Bus Network proposals.

• System needs to be complementary to the proposed scheme in Bath (Line 1), withboth lines forming part of an identifiable network.

• Ability to maintain existing cyclist and pedestrian provision and where possibleenhanced.

• Ability to maintain the amenity value of the existing corridor and where possibleenhance this value.

Technology Assessment – Scope of Work

The technology assessment will need to include consideration of the following:

• How well the technology meets the high-level scheme objectives set out in GBSTS.

• How well the technology meets the key success criteria.

• How well the technology addresses the local considerations.

• What the physical opportunities and constraints are of the technology:

o Ability to restrict access to authorised vehicles – ease of which other vehiclescan be restricted form entering the alignment.

o Ability to leave and join at intermediate points – to provide services fromfurther afield to leave and join the alignment but also system resilience interms of vehicle breakdown.

o Alignment width (land take) – horizontal alignment.

o Tracking/docking accuracy – ability to deliver level boarding.

o Severance – ability to negotiate or cross the infrastructure.

o Junctions with the road network – impact on road network at junctions.

o Maintenance requirements – system and vehicle maintenance and impact ondepot facilities.

o Provision for service utilities, future maintenance of these and operationalimpacts on the system.

o Depoting and maintenance issues.

• What the impacts of the technology are:

o Environmental, including emissions and wider environmental impacts suchas an estimated comparison of energy requirement of constructing and

3

operating the system compared with bus-based guided system - e.g.amounts of construction materials.

o Other modes including car, pedestrians, cyclists, bus services, servicing etc.

o Other.

• How deliverable and viable the technology is including:

o Cost – capital cost of infrastructure and vehicles and how this related to bus-based solutions.

o Any implications for the level of local contributions DfT might require for thedifferent technology options.

o Operating issues (e.g. vehicle reliability, energy efficiency) and costs ofinfrastructure and vehicles.

o Vehicles – assessment of vehicles including capacities,.

o Risks associated with the technology.

o Industry acceptability - i.e. whether it is an accepted technology has a UKSafety case and whether the technology is in operation, its operationalhistory (particularly UK experience).

o Likely position of DfT on technology options.

The assessment also needs to consider the costs of the ULR technology for the full fourline BRT network including a possible future extension to Bristol International Airport.

The assessment must be undertaken in consideration of the Department for Transportguidance on major scheme appraisals and other relevant guidance documents (forexample CfITs Affordable Mass Transit report).

Timescales

The assessment needs to be undertaken and results reported by mid July.

Outputs

The expected outputs from this commission are:

• A published, independent report that can be shared with key stakeholders in to theassessment of Ultra Light Rail technology for Ashton Vale to Temple Meads butalso in the context of the entire proposed BRT network fr the sub-region.

• Presentation of the report conclusions to the Project Board.

Technology Review


Appendix

APPENDIX B

HYBRID ULTRA LIGHT TRANSIT SYSTEM (HULTS) REPORT

Prepared for

BRISTOL ELECTRIC RAILBUS LTD (Designed by TDI)

Bristol Electric Railbus Ltd

Hybrid Ultra Light Transit System (HULTS):

An Alternative Proposal to Bus Rapid Transit from Bristol City Centre to Long Ashton Park and Ride

Desktop Study

Report

June 2008

This document has been prepared for the titled project or named part thereof and should not be relied upon or used for any other project without an independent check being carried out as to its suitability and prior written authority of Scott Wilson being obtained. Scott Wilson accepts no responsibility or liability for the consequence of this document being used for a purpose other than the purposes for which it was commissioned. Any person using or relying on the document for such other purpose agrees, and will by such use or reliance be taken to confirm his agreement to indemnify Scott Wilson for all loss or damage resulting there from. Scott Wilson accepts no responsibility or liability for this document to any party other than the person by whom it was commissioned.

Revision Schedule T:\TTS\Projects\D119734\F07 Reports

Hybrid Ultra Light Tram System (HULTS) – An Alternative Proposal to Bus Rapid Transit between Bristol City Centre to Long Ashton Park and Ride June 2008

Rev Date Details Prepared by Reviewed by Approved by

01 30/06/08 Report Jose Marquez Senior Consultant

Mark Brackstone Principal Consultant Gary Davies Senior Consultant

Adrian Withill Technical Director

Scott Wilson The Crescent Centre Temple Back Bristol BS1 6EZ Tel. 0117 917 1200 Fax. 0117 930 0342 www.scottwilson.com

Table of Contents

1 Executive Summary ................................................................... 4

2 Introduction and Background ................................................... 5

3 The HULTS Concept................................................................... 9

4 Joint Local Transport Plan Objectives ................................... 12

5 Infrastructure and Route.......................................................... 14

6 Vehicle Options ........................................................................ 18

7 Operations ................................................................................ 20

8 Environmental Impacts ............................................................ 21

9 Finance ..................................................................................... 22

10 Meeting Greater Bristol Strategic Transport Study Objectives - GBSTS.................................................................. 23

11 Appendices............................................................................... 28

4

1 Executive Summary

1.1 This study has been commissioned by Bristol Electric Railbus Ltd to investigate Hybrid

Ultra Light Tram System (HULTS) as an alternative to the proposed Bus Rapid Transit

(BRT) system between Bristol City Centre and Long Ashton Park and Ride (P&R).

Objectives

• The aim of this study is to give a better understanding of HULTS to local authorities and show that HULTS meets the Greater Bristol Strategic Transport Study objectives.

• This study is an attempt to introduce HULTS to the Local Authorities as a public transport alternative rather than a bus only system.

1.2 HULTS is a light tram using Hybrid Propulsion Technology which aims to reduce fuel

consumption and emissions. HULTS is an environmentally friendly public transport

alternative which can operate within Pedestrian or Low Emission Zones (LEZ), such as,

Broadmead shopping area.

1.3 HULTS is proposed along a corridor into Bristol using the disused stretch of railway

alignment between Bristol City Centre and Ashton Gate.

1.4 The main function of HULTS will be to complement or replace the existing Long Ashton

Park and Ride (P&R) service by providing a high quality connection to the city centre.

1.5 There is a requirement to provide transport to major destinations along the route with

convenient direct access to the Bristol City Centre. This will be an additional public

transport service for areas such as Spike Island not currently served by P&R. The

following benefits would result:

• Convenient access to the Centre from Ashton, Southville, Hotwells and Spike Island

• Convenient access from the Centre for visitors to CREATE and the Records Office

• Convenient access to the University of the West of England (UWE), Bower Ashton, Ashton Park School and Ashton Court

• Reduction in traffic and congestion on Hotwells Road with consequent environmental improvement.

1.6 HULTS will support the general objective of improving the quality of the environment in the

city whilst preserving its economic life and reducing its carbon footprint. This objective will

be achieved by providing an attractive, clean, energy efficient alternative to the car to

access key central locations.

1.7 HULTS will provide a unique opportunity for the West of England Partnership to pioneer a

movement towards genuinely sustainable urban regeneration and suburban development

which would support the aspiration for Bristol to become the Green Capital of the South

West.

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2 Introduction and Background

Introduction

2.1 The City Centre to Long Ashton link is proposed as a key part of a Rapid Transit Network

(RTN) designed to reduce congestion and pollution in the city and improve access from

outer neighbourhoods to central Bristol, as proposed by Joint Local Transport Plan (JLTP).

The proposal will provide a foundation for detailed sustainable development of the area

along the route.

2.2 Already served by a bus link, the Long Ashton Park and Ride is located just off the A370 to

the South West of Bristol. However, there is ample evidence from towns and cities around

the world that car drivers and users cannot be tempted from their cars in large numbers

merely to ride on buses, despite the fact that buses are important elements in any

integrated transport system.

2.3 However, a much larger proportion of car-users are prepared to use public transport when

a modern light rail or tramway system is their mode of transport for all or part of their

journey.

2.4 The proposed Hybrid Ultra Light Transit System (HULTS) service from Long Ashton Park

and Ride to Bristol city centre, however, would serve communities along the route and

cater for further expansion of the existing settlement in Ashton Vale.

2.5 HULTS is an appropriate mode of transport interacting with pedestrian zones and cycle

paths to bring communities together, principally in the area of Ashton Vale which could

benefit from further development. The region suffers from the lack of suitable public

transport leading to two post-modern social problems related to transport:

• Social Exclusion

• Social Fragmentation

2.6 These two social problems are tackled by HULTS scheme by providing safe and

comfortable means of transport to visit local shops and other amenities along the route.

2.7 The HULTS proposal strategy can also lessen the impact of traffic congestion by providing

an attractive alternative to car use.

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2.8 The HULTS proposal will use a Hybrid-Power concept which would result in:

• Lower investment and running costs than conventional Light Rail Tram (LRT)

• Same capacity, safety and comfort as LRT

• Low atmospheric emissions

• Low noise, vibration and visual pollution

• No overhead wires or third rail power system like conventional LRT

• Speed and acceleration suitable for operation in pedestrian areas, with road traffic or segregated routes

• Energy efficiency due to Brake Energy Recovery (BER)

• Low environmental impact to immediate surroundings

• Ease of travel

Background

2.10 Bristol’s first horse drawn tram system was established in the 1870s. In 1890, Bristol

became one of the first cities in the UK to adopt electric trams.

2.11 At its height, the tram system extended throughout the major suburbs of Bristol. It

extended as far as Westbury on Trym and Horfield to the north, Kingswood to the east and

Brislington and Bedminster Down to the south.

2.12 Figure 1 shows the tramway by the Victoria Rooms in the early 1930s. Trams shared the

same space with pedestrians and are still doing so in many cities around the world.

Figure 1 – Tramway by Victoria Rooms in Bristol Source: http://www.emep.dsl.pipex.com/tram02.html#Route

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2.13 Nevertheless, in conjunction with the railway and bus systems, the trams provided an

affordable and integrated transport system for the people of Bristol. They were particularly

useful for transporting large numbers of working men and women from their homes in the

suburbs to their places of work. Figure 2 shows the centre of Bristol with buses and trams

sharing the road.

Figure 2 – Tramway in the centre of Bristol Source: http://www.emep.dsl.pipex.com/tram02.html#Route

2.14 Unfortunately, the tram system ceased to operate in 1941 when a Luftwaffe bomb

destroyed the power station during the Good Friday Raid on the city.

2.15 Bristol’s urban layout still retains many of the spaces created by these original tramway

and train routes. Many of these routes survive as disused areas of brownfield land or have

been incorporated into adjacent developments. The urban ‘memory’ of this transport

infrastructure survives in the fabric and layout of the city to the present day either as

isolated stretches of Brownfield land or as intact, but largely disused, stretches of track

(often in use as public footpaths).

2.16 The Bristol City Council, however, has been involved in feasibility studies and schemes in

order to bring trams back to the city. The latest Light Rail Tram (LRT) system proposed for

Bristol in the early 2000s, however, has not being endorsed by the central government

because a detailed and costed proposal was not included in the Local Transport Plan

(LTP).

2.17 The recent Joint Local Transport Plan (JLTP) - 2006, in its section 10.6.22, nevertheless,

stated that long-term public transport solutions for the West of England area must contain

high profile public transport schemes rather than the short-term bus-based ones. JLTP

believes it is essential to devise a future Light Rail Tram (LRT) network to meet the longer

term needs of the area and facilitate the potential housing and employment growth.

2.18 The HULTS scheme fulfil the short and long term objectives proposed by JLTP due its

tramway conception, such as LRT, with affordable cost, such as bus rapid transit.

8

2.19 The proposed HULTS route between Bristol City centre and Long Ashton will incorporate a

number of elements of Bristol’s Industrial heritage including:

• Long stretches of currently derelict railway track along the Ashton Meadows Loop

• Ashton Avenue Bridge

• Stretches of disused track running towards the harbour area under Vauxhall

Bridge

• Existing track by the Industrial Museum

• The Prince Street Bridge

• The harbourside and Rupert Street

2.10 The route would also pass through more than three conservation areas, and would be

visible from a very large number of scheduled monuments and listed buildings.

2.11 A HULTS network in Bristol would assist preservation and appreciation of the historic

environment in a number of ways:

• Reuse of the original train and tram routes would represent a return to Bristol’s

heritage

• Increased public access to, and appreciation of elements of the historic

environment currently disused or rarely visited

• A reduction in traffic would improve the setting and ambience of the city centre

conservation areas

• The opportunity to appreciate these areas from the trams would also represent a

positive impact of the development

• The development could have a similar impact on the setting and appreciation of

the city’s many scheduled monuments and listed buildings

• An improved transport infrastructure will also assist in promoting tourist access to

the historic core of Bristol and create an ambience which more accurately reflects

the historic character of the city

• A reduction in traffic levels will help preserve the historic environment by reducing

the corrosion caused by pollution

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3 The HULTS Concept

3.1 HULTS has the capacity to carry up to 60 passengers per vehicle, as shown in Figure 3, running on a lightweight track at frequent demand driven stops throughout the route.

3.2 If required, two vehicles can be coupled to double vehicle capacity during peak-hours in

order to reach demand without the need to reduce the headway time (time between trams).

Figure 3 – Schematic Hybrid Ultra Light Tram System - HULTS Source: Parry People Movers (PPM)

3.3 The Hybrid Technology will allow HULTS to be operated on Pedestrian or Low Emission Zones, such as, Broadmead shopping area. HULTS has the best environmental performance of any comparable mode of transport.

3.4 Tram operation in pedestrian zones is not new and it is used in several cities around the

world. Figure 4 shows examples in the UK of conventional electric trams operating in Nottingham and Manchester.

Figure 4 – Trams operating on pedestrian and low emission zones Source: http://www.citytransport.info/Zones.htm

3.5 However, HULTS does not need overhead wires, shown in Figure 4, with HULTS being energy autonomous, generating its own power. HULTS will operate safely and unobtrusively in Pedestrian Areas, mix with other road traffic on streets and use segregated routes where appropriate.

10

3.6 HULTS tramway does not need to be insulated because the system does not require external electrification. This considerably reduces the time and cost for its installation. The investment costs of HULTS is about 70-80% lower per kilometre than that of conventional electric tram systems.

3.7 Apart from being more environmentally friendly and energy efficient than conventional

diesel buses, HULTS has a visible predictable path like any tram system. HULTS meets the public desire for accessibility to traffic free zone.

3.8 HULTS will be powered by a two litres Internal Combustion Engine (ICE) fuelled by bio-

methane and flywheel for complementing the necessary energy demand.

HULTS Flywheel 3.9 The HULTS system uses a flywheel, drawing kinetic energy to accelerate the vehicle and

then recovering brake energy in order to minimise fuel consumption. Flywheels are reliable energy storage device which have been equipping steam locomotives since the beginning of the last century.

3.10 The HULTS flywheel is made from steel laminates, 1m in diameter and 500kg mass,

rotating at a maximum speed of 2,500rpm and is safe, reliable and easily maintainable.

HULTS Fuel

3.11 HULTS primary propulsion system is currently fuelled by gas. However, HULTS can be

equipped with a flexible fuel engines which can effectively burn various fuel types. 3.12 Several countries, e.g. Brazil, Sweden and the USA, have been running their car fleet with

flexible-fuel engines (FlexiTM Engines) powered by pure petrol or alcohol or natural gas or a combination of petrol/alcohol known as blended petrol.

3.13 HULTS has the capability to use the lowest carbon fuel available, i.e. from Bio-Methane

produced from renewable waste as fuel to hydrogen-fuelled internal combustion engines or fuel cells.

11

3.14 In addition to low emissions and fuel consumption HULTS will bring other benefits,

including:

• The use of existing railway tracks without any track design modification

• Efficiency of energy and operation due to its hybrid concept

• Affordable tramway infrastructures comparable to the guided Bus Rapid Transit (BRT) route

• Rapid implementation and operation with a similar timescale to that allowed for BRT

• Three times operational life span compared to a standard diesel bus

• An excellent platform for system innovation and the testing and implementation of new technologies.

National Industrial Symbiosis Programme (NISP) interest in the HULTS project

3.15 HULTS is a proposal engaged in the sustainable urban mobility claim of the Bristol

Environmental Technologies and Services (BETS) sector. Therefore, it has called the attention of NISP which is a governmental initiative sponsored by DEFRA and one of the partnership members of BETS.

3.16 NISP brings together companies from all business sectors with the aim of improving cross

industry resource efficiency through the commercial trading of materials, energy water, and /or by-products together with the shared use of assets, logistics and expertise.

3.17 Scott Wilson’s NISP team has been shown interest in the HULTS proposal for Bristol in

order to look for suitable and reliable suppliers of Bio-Methane in the West of England area.

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4 Joint Local Transport Plan Objectives

4.1 The Joint Local Transport Plan (JLTP) has been set up as a joined initiative of Bristol,

Bath, North East Somerset, North Somerset and South Gloucester Councils to plan and

deliver transport improvements in the area (West of England Partnership).

4.2 JLTP proposal will:

• Provide improved access and regional regeneration

• Set environmental standards

• Offer social equality and opportunity through readily available public transport for all

• Meet public transport needs

• Improve integration – by providing easy interchange between ferry, bus and rail stations at key locations

• Encourage modal shift from cars to public transport

• Offer easy walking routes between transport stops and homes/workplace

• Provide high levels of environmental performance to meet strict sustainability criteria

• Be an economically viable system

4.3 The HULTS proposal is in accordance with what has been proposed by JLTP. Achieving

these objectives will provide, above all, a system which adds value to numerous

development sites along the routes.

4.4 According to JLTP, the Bristol, Bath and North East Somerset, South Gloucestershire and

North Somerset area will accommodate an extra hundred thousand new homes during the

next 20-30 years. This will generate greater expectation for people’s mobility and

accessibility, increasing the pressure on the public transport system and on Local

Authorities for:

•••• Suitable public transport

•••• Congestion reduction solutions

•••• Air quality improvement

•••• Road safety

4.5 Regarding public transport, JLTP is looking to submit two major schemes to improve the

bus network in Bristol and Bath.

4.6 Although these schemes have been developed in partnership with the main bus operator,

it does not mean Rapid Transit Systems have to rely on buses to give the area a reliable

and modern public transport service.

13

4.7 The schemes will submit bids to the Department fro Transport (DfT) to develop:

• Rapid Transit

• Selective highway enhancements

• Weston-super-Mare Package

4.8 HULTS is a economically and viable public transport system and a cost effective

alternative to bus rapid transit that could be used to address many of these goals and

objectives.

4.9 The current fuel situation will mean that car-users will demand suitable and sustainable

public transport as an alternative to the car. HULTS, therefore, is proposed as an

alternative to supplement the public transport network, with high public acceptance and

thus avoiding the high costs of oil dependence.

4.10 In order to have support and interest of the public and stakeholders in developing this plan,

suitable means of transport for different routes need to be selected.

4.11 JLTP, however, recognises that several obstacles will have to be faced and that any failure

in tackling transport problems will have adverse social and economic impacts.

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5 Infrastructure and Route

Infrastructure

5.1 HULTS has a unique low-cost infrastructure which allows the tram system to be applied to

any route. HULTS does not require any external electrification, nor is there a need for track

insulation as required by electrified tram systems.

5.2 Therefore the costly relocation of cabling and utility services under the track, such as,

water and sewage will not be necessary. HULTS installation costs are comparable to, or

lower than, the cost of guided segregated busways.

5.3 HULTS will use the most advanced technique of permanent way installation used for tram

system applications in the UK. This technique allows minor works to be undertaken around

or under the track with limited disruption of the tram service. If more major road works have

to be undertaken involving services (such as sewers) lying underneath a significant section

of track, a temporary diversionary track can be established that has a simple interface with

the fixed track and allows tram services to be maintained throughout the duration of the

works.

5.4 High performance polymers have opened up the possibility to construct an embedded rail

track with very high vibration isolation performance as well as good electrical insulation.

Although HULTS does not require electrical insulation, HULTS track will add this extra

feature. Figure 5 shows in details a section of an encapsulated rail and an embedded

track.

Figure 5 – Pre-coated and embedded rail Source: ALH Rail Coating ltd

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5.5 HULTS has been applied in Stourbridge in a train-tram operation as an alternative to the

conventional diesel train unit. The link between the Stourbridge Junction to the town centre

has been using the Parry’s People Movers (PPM 60) unit. PPM will provide the chassis

and the hybrid system to HULTS.

Route/Plan

5.6 A schematic of the proposed route is shown in Figure 6.

5.7 As a first application, HULTS would be designed as the prime means of conveying people

between Long Ashton Park & Ride (LA P&R) and key destinations in Bristol such as

Temple Meads, Temple Quay, Cabot Circus, Broadmead and the Centre whilst serving

intermediate locations such as Ashton Gate, Spike Island and Harbourside.

Spike Island

Figure 6 – Schematic of proposed rapid transit route, Bristol Centre to Long Ashton P + R

Ashton Gate

Extension to P + R

LTP preserved route

LTP preserved route

Heavy rail route

To Portishead

Wapping Wharf

Harbourside

Cumberland Basin

Ashton Meadows

Southville

Prince Street Bridge

Portishead line

Long Ashton P+R

Ashton Swing Bridge

City Centre

Broadmead

Temple Meads

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5.8 The route uses the existing rail alignment between Wapping Road and Ashton Gate, via

Spike Island and Ashton Meadows, serving the Museum of Bristol, SS Great Britain,

residents near Vauxhall Foot Bridge, CREATE Centre, BCC offices, and Ashton Gate area.

It then crosses the heavy rail line and reaches Long Ashton Park and Ride by a route to be

defined by further discussion with planners.

5.9 In the Bristol City Centre various options are available. Figure 7 shown two routes

selected for the Supertram in 1999.

Figure 7 - Options for City Centre Routes Source: Bristol Electric Railbus

5.10 The preferred route is the route currently preserved in the Joint Local Transport Plan. The

route from Ashton Vale would cross Prince Street Bridge and join the above route at The

Grove.

5.11 Subject to discussions with planners, the route would be extended from Broadmead to

Temple Meads, via Cabot Circus. This would provide a valuable convenient link between

the shopping centre and the railway station.

17

5.12 Three tram routes are envisaged:

(1) Long Ashton P&R to Broadmead/Cabot Circus (2) Long Ashton P&R to Temple Meads (3) Broadmead/Cabot Circus to Temple Meads

LA P+R to Broadmead/Cabot Circus

5.13 This service would provide access to the Shopping centre from the Park and Ride terminus

and from intermediate stops on Spike Island.

LA P+R to Temple Meads

5.14 This service would provide access to Temple Meads Station and the Temple Quay and

Redcliffe areas – from the Park and Ride terminus and from intermediate stops on Spike

Island.

Broadmead/Cabot Circus to Temple Meads

5.15 This service would provide access to the Shopping centre from Temple Meads Station and

the Temple Quay and Redcliffe areas.

5.16 Service frequencies would be adjusted to meet demand.

Practicalities

5.17 The tram design is such that it can mix freely with pedestrians in car-free zones, in a safe

and unobtrusive manner, mix freely with other traffic where required or operate on simple

to construct segregated tramway.

5.18 A high frequency service will result in only a short wait time at the stops covered. Tickets

will be purchased in advance of travel from vending machines at each stop or by season

ticket for regular users via Internet transaction or designated outlets.

Depot

5.19 The vehicle fleet will be stabled in a secure depot / compound overnight or when out of

service where repair, maintenance and routine cleaning can be carried out.

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6 Vehicle Options

6.1 The vehicles will be based on a design which has been modified for commercial

application in Greece in 2004, shown in Figure 8. The vehicle evolved from the vehicle

successfully operated by Bristol Electric Railbus Ltd in Bristol from 1998-2000 and has now

been applied to the Stourbridge Junction – Stourbridge Town line as a permanent public

transport mode as shown in Appendix 1.

Figure 8 – Proposed HULTS Source: Transport Design International Ltd

Tram Body

6.2 The body will be of lightweight construction but built on a substantial chassis, provided by

PPM, and superstructure. Access for passengers, including wheelchairs, will be by level

entry from platforms or kerbs, by doors on either side of the vehicle. The vehicles can be

driven from either end and will have a maximum capacity of 60 passengers. There is the

possibility of coupling two vehicles together to double the capacity at peak hours.

Drive Train

6.3 The elements of the hybrid drive train are as follows:

• Primary power – A compact, high efficiency, low emission gas engine running on biogas derived from renewable waste sources.

19

• Energy store and regenerative drive – The gas engine drives a flywheel energy storage unit which also receives energy from regenerative braking. The flywheel provides the power to the drive motors for acceleration and stores the brake energy. This is proven, innovative hybrid technology giving up to 40% fuel savings.

• Fuel store - A tank for compressed natural gas is built into the roof of the vehicle. Its capacity will enable re-fuelling at the depot on a once a day basis. The depot will incorporate fuel storage and refuelling facilities.

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7 Operations

7.1 HULTS operational characteristics comply with any light rail including the capability of

running on former railway lines, alongside highways or on street and pedestrian areas.

Work will be needed to integrate with the city centre traffic signals.

7.2 With the advent of the tram-train operation, HULTS can also share tracks with heavy rail

vehicles with the ability, however, to enter city centres, safely sharing urban areas with

pedestrians and cyclists.

7.3 The system is designed for high reliability. Operational costs will be low because of the

low fuel consumption. Other operating costs, including vehicle leasing costs, along with

other operational requirements will be similar to those of an equivalent bus service.

7.4 Maintenance and refuelling will be undertaken when individual vehicles are out of service

either daytime off peak or evenings.

7.5 Vehicle maintenance costs and requirements are likely to be low compared with equivalent

buses. Track maintenance costs will be lower than those of guided busway because of the

durability of steel rails, and the high quality of embedded and coated rail technology.

Evidence will be given when a feasibility study is commissioned.

7.6 Operational and investment costs and operational risks (Appendix 2) have to be assessed

in a feasibility study.

7.7 HULTS is not a rigid concept, but a flexible one using advanced propulsion which fits

between conventional buses and electrified light rail trams. HULTS has the advantage of

being cost competitive with bus rapid transit systems, but cheaper to operate for a given

capacity.

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8 Environmental Impacts

8.1 The vehicle will have very low impact on the environment. Details are as follows:

Atmospheric Emissions

8.2 Atmospheric emissions will be low because of the low fuel consumption and the use of

biomethane as fuel. As a result, net CO2 emissions will be only 18% of those of an

equivalent diesel bus due partly to the credit given to the use of renewable waste derived

biofuel.

8.3 Pollutant emissions will also be reduced to below Euro 6 equivalent levels by use of

methane as fuel with 100% combustion.

Noise

8.4 Because of the small size of the engine and its relatively light load due to hybrid operation,

noise levels will be low in comparison to the equivalent diesel buses.

Life Cycle Costs

8.5 The vehicle will be robust and by virtue of its service will have a useful life of 30-40 years

compared with 8-13 years for conventional buses

Pedestrian Safety

8.6 Guided vehicles are inherently safer than unguided vehicles, particularly in pedestrian

areas due to the visibility of the track and close control of the vehicle movement. HULTS is

less environmentally intrusive. The accessibility of pedestrian areas is enhanced without

affecting the quality of the environment.

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9 Finance

Infrastructure Costs

9.1 The costs represent a substantial part of the project. Therefore, any estimate cost assessment has to be led by discussion with authorities, contractors and services providers when route alternatives are established.

Vehicle Provision Costs

9.2 HULTS investment costs will depend on vehicle characteristics and the fleet required

complying with demand. Vehicle price, nevertheless, tend to decrease according to the

number of vehicles ordered.

9.3 However, according to personal discussions and non-official information with PPM, the

vehicle manufacturer, the HULTS vehicle price could be around £300-350k.

9.4 In order to predict HULTS costs for the proposed route for Bristol City, a more elaborate

and thorough feasibility study is necessary.

9.5 In terms of fuel costs alone, bio-methane natural gas is cheaper than most fossil-based

fuels, which means that running costs for natural gas vehicles can provide considerable

savings compared to diesel costs. According to the Asia Pacific Natural Gas Association

(ANGVA), bio-methane is 35% and 30% cheaper than diesel and petrol.

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10 Meeting Greater Bristol Strategic Transport Study objectives - GBSTS

Extending Choice of Transport Modes for All, and in Particular for Private Car Drivers to Encourage a Shift to Public Transport

10.1 HULTS is designed to provide an attractive alternative to the car to access central and

southern parts of Bristol, both for residents and for commuters and visitors approaching

from the South and South West.

10.2 Residents of Bower Ashton, Ashton Vale, Southville and Spike Island, as well as university

and school staff and students based in the area, will have the option of accessing Bristol

by way of quality light rail transport, while car drivers will have the option of parking at Long

Ashton and completing their journey into Bristol by light rail.

10.3 HULTS design will be to a standard normally expected from modern light rail services,

which have proved to be more effective than bus services in attracting car drivers.

Promoting Sustainable Development by Providing High Quality Public Transport Links

10.4 The route passes by and through many development areas, including Spike Island,

Cumberland Basin, Ashton Meadows and beyond. HULTS service will enhance the quality of the development by providing an attractive alternative to car use and allowing the viable development of a proportion of car free housing, a key feature of sustainable development.

Improving Access to Public Transport Areas which Currently Have Poor Provision

10.4 At present, Spike Island, Southville, Ashton Gate and Ashton Vale are poorly served by

public transport. This proposal would result in a frequent service to these neighbourhoods giving access to the Centre and to the wider transport network.

Improving Integration of the Public Transport Network 10.5 The proposed service will link with the 500 circular bus service on Cumberland Road, the

ferry services at the Nova Scotia and Museum of Bristol, the Greater Bristol Bus Network in the Centre and near the Bus Station and with the national rail network at Temple Meads station and, when the heavy rail service is operative, with the Portishead line at an interchange at Ashton Gate.

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Promoting Social Inclusion by Improving Access to Employment, Retail, Community, Leisure and Educational Facilities

10.7 The route will link with the David Lloyd centre, the existing and proposed new football

stadium, Ashton Park School, UWE Bower Ashton, Ashton Court, The Riverside Garden Centre, Bristol Record Office and other B Bond offices, including the CREATE Centre, Spike Island Arts complex, The SS Great Britain and Maritime Heritage Centre, The Museum of Bristol, The Centre, North Harbourside and College Green, Redcliffe and Temple Quay, Broadmead and Cabot Circus.

Improving Safety Along the Corridor by Providing a High Quality Public Transport Alternative to the Private Car

10.6 The service will meet 100% the quality standards of conventional light rail transport giving:

•••• Improved safety to pedestrians

•••• Improved safety to standing passengers and comfort in general due to the high ride

quality

•••• Level entry for wheelchair access and rapid boarding

•••• Regular reliable services

•••• Attractive vehicles

Meeting the Specific Scheme Objectives

Mode Shift from Car

10.7 The Park and Ride service is specifically designed to attract drivers, particularly those

entering Bristol via the A370, to leave their cars and complete their journey by the light rail

service. Also, those living or working in the vicinity of the route will be encouraged to use

the service rather than having to seek parking spaces at their destination.

Helping Reduce Traffic Congestion

10.8 By providing an attractive alternative to car use, traffic will be reduced as will the demand

for central area parking. This will alleviate congestion in the City Centre, Hotwells,

Bedminter and Southville

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Contributing Towards Economic Growth 10.10 The proposed service will increase the accessibility of commercial areas such as

Broadmead, Cabot Circus, Temple Quay and also developing areas such as Spike Island, Cumberland Basin and Ashton Vale. It will allow for the sustainable expansion and economic development of South Bristol without significantly increasing its carbon footprint.

Addressing the Local Context Criteria

Low Emission Technology 10.11 The vehicles are designed for maximum fuel efficiency by use of light rail technology to

reduce wheel losses and hybrid propulsion to recover brake energy. Fuel consumption is thus up to 40% below that of the equivalent standard bus. Emissions are further reduced by use of compressed natural gas which is low carbon and clean. It is proposed to use renewable methane derived from waste sources so as to render the operation carbon neutral.

Ability for Services to Serve All Four Authorities 10.12 Bristol and North Somerset will be served by this route. If appropriate, the technology

could be applied along all the rapid transit corridors proposed in the Joint Local Transport Plan with similar environmental benefit.

Retention of Road Network Capacity 10.13 It is not intended to remove any road capacity. Where a reserved path is not available,

e.g. in the centre, the vehicles will share road space with other traffic or with buses on bus lanes. Little impact on traffic flow is expected, except for an improvement due to a general reduction in traffic.

Integration with the Network of Showcase Bus Corridors and GBBN Proposals

10.14 Where the service shares road space with the bus services (e.g. in the Centre) full

integration at stops is envisaged facilitating transfer and interchange between services. The operators of the tram service will participate in any joint ticketing system that emerges in order to reduce boarding delays and allow through, city-wide, ticketing for passenger convenience.

Integration with the Proposed Bath Line 1 Scheme 10.15 No direct connection with the Bath scheme is proposed at present but there is no

fundamental incompatibility. Bus Rapid Transit and light rail can share the same alignment so that both can be part of an integrated network.

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Maintaining, and where Possible Enhancing, Existing Cyclist and Pedestrian Provision.

10.16 Features will be incorporated to ensure the safety of pedestrians and cyclists in areas of

shared use in accordance with HM Inspectorate requirements. By use of stretches of single track, the existing pedestrian and cycle path along the New Cut will be preserved.

Maintaining Amenity Value of the Existing Corridor 10.17 The light rail service will be designed to have minimal impact on the surroundings

particularly regarding noise and pollutant emissions. The amenity value could be enhanced by the added accessibility which the service provides.

Physical Opportunities and Constraints of the Technology

Ability to Restrict Access to Authorised Vehicles 10.18 Most of the route will be on dedicated tramway though access will be available if required,

on occasions, to heavy rail traffic, in this case, the Bristol Harbour Railway steam operation. Except in the centre and on the Ashton Level Crossing, road traffic will be excluded from the route.

System Resilience in Terms of Vehicle Breakdown 10.19 In the unlikely event of vehicle breakdown, the normal practice of propelling the vehicle

from behind using a serviceable vehicle will be employed to move the faulty vehicle off the route.

Alignment Width (land take) – Horizontal Alignment 10.20 For a double track the width of land take is under 7.2m. Much of this is land already

reserved for LRT. It is envisaged that sections of the route will be single track with passing points. This is to avoid interference with cycle and pedestrian routes along the New Cut. Doubling of this stretch would require use of Cumberland Road, possibly by removal of parking spaces.

Ability to Deliver Level Boarding 10.21 The tramway is guided throughout so that gapless level entry is provided at every stop.

Ability to Negotiate or Cross the Infrastructure 10.22 Light rail is inherently safe for pedestrians, who can cross the track without impediment

with full awareness of the route of oncoming light rail vehicles. Other traffic can cross the track which, if on road, is flush with the road surface.

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Impact on Road Network at Junctions 10.23 Where the route is along the road (e.g. in the centre), the vehicles mix with other road

traffic or run along buslanes. At junctions the vehicles will obey normal traffic signals unless special priority arrangements are made.

Maintenance Requirements 10.24 The light rail system will have its own purpose-built depot where routine maintenance will

be carried out.

Deliverability and Viability of the Technology

Capital Cost of Infrastructure and Vehicles.

10.25 The rail infrastructure can be installed at a cost of below £3M per km which compares

favourably with the cost of guided busway and has the advantage of being more durable.

10.26 The vehicle cost per passenger is similar to that of the equivalent hybrid low emission bus.

The leasing cost may be lower due to the longer life of light rail vehicles compared with buses.

Operating Costs of Infrastructure and Vehicles and Reliability 10.27 Operating costs are below those of the equivalent bus services on account of the fuel

costs and track maintenance cost which are lower than that of the equivalent busway.

Risk Associated with the Technology. 10.28 The hybrid light rail technology has already been successfully demonstrated on the

Stourbridge Junction to Stourbridge Town branch service where it has gained acceptance by Her Majesty’s Rail Inspectorate (HMRI) for daily service operation on this line. The vehicles proposed for the Bristol operation will employ the same drive technology.

UK Safety Case 10.29 Street running will require permission under the Transport and Works Act. The proposers

have been advised by HMRI that the costs of obtaining this will be proportional to the scheme cost and therefore will not be prohibitive and will be incorporated into the overall cost.

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11 Appendices

Appendix 1 – Vehicle Characteristics Vehicle Technical Data

Length 9.6 m Width 2.4 m Height 2.7 m Entry height 0.45 m Seats (approx) 22

Passenger capacity 60

Max. speed 65 km/h Tare 9 t

Primary Drive Ford 2 litre gas engine Hybrid drive system, brake energy recovery 2x 12v battery supply for ancillary power

Energy Store Unit (per drive):

500kg 1m diameter flywheel, normal effective speed range 1000-2600 rpm

Transmission: Linde hydrostatics through final drive gearbox,

Braking: Normal (regenerative) braking 1m/s

2

Emergency braking through sprung on, air off discs at 3m/s2

with normal adhesion (Tread and or track brakes available if required) Air operated sanding gear to the driven wheels

Running Gear: Solid axle with wheels 610mm diam. to tram profiles Suspension, chevron type with coil spring optional

Heating (per vehicle): 2x Water heated air blown

Maximum Speed: 65 km/h

Minimum Curvature: 15m radius

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Appendix 2 – Costs and Risks

Provisional Operational Costs

These costs are subjected to a thorough feasibility study for specific route or network. This will depend on:

•••• Route •••• Operational features •••• Vehicle characteristics for the project •••• Availability of fuel •••• Depot facilities •••• Administration

Project Risks.

1. Project Delivery

Risk Control Mechanisms Remaining Risk

Unable to fund capital Infrastructure Vehicle Development Vehicle Costs

Pre project requirement that infrastructure is funded by the development. Multiple sources to be pursued Investigate at feasibility study stage. Tender supply/builder

Low- Project will not be initiated without agreement. Low- Funds need to be secure before contract. Low- Leasing Co. and operator have to be happy with costs and returns.

Unable to deliver acceptable design.

Competent Design with experienced independent technical support. Test procedures built into project from the start. Assessed at project feasibility stage.

Low. Elements of technology have been demonstrated elsewhere.

Do not achieve planning or regulatory consents

Check with planning authority and light rail regulators early and before contract.

Low. Development is largely in rebuilt areas and planning needs can be incorporated.

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2. Operational Risks.

Risk Control Mechanisms Remaining Risk

Inadequate patronage for viability.

Clear professional assessment at feasibility study stage. Concept has to be integral to development to encourage usage.

Low. Rail characteristics of HULTS has been proved more attractive to passengers in other cities in the UK than bus system

Vehicles unreliable Intensive pre-testing.

Low. HULTS reliability has been thoroughly tested for more than 10 years already. Further tests will depend on planned route only.

Operating costs exceed predictions.

Clear professional assessment at feasibility study stage. Good operating margin built in from start. (Operator convinced)

Low. Costs should be quite predictable once capital/leasing costs are known.

Technology Review


Appendix

APPENDIX C

DESIGN REQUIREMENTS FOR STREET TRACK, OFFICE OF THE RAIL REGULATOR, MAY 2008

Technology Review


Appendix

DESIGN REQUIREMENTS FOR STREET TRACK

Tramway Technical Guidance Note 1

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Contents

Introduction 3

Design requirements for street track 4

Features of UK second generation track designs 7

Systems with in-situ embedment 7

Systems using pre-cast embedment 9

Generic problems with concrete slab construction 10

Generic problems with floating rail construction 11

Solutions capable of meeting the requirements 12

Photographs and diagrams

1. General street track with tram 3

2. Lateral roll of rails causes road surface damage 8

3. Welding a rail joint 9

4. ALH6 polymer pre-coated SEI 41GP grooved rail 9

5. Pre-coated rail installed on concrete slab 10

6. Tie bar arrangement of rails used on the Blackpool tramway 12

7. Example of traditional track construction in Graz 13

8. Grooved rail profiles 14

9. Twinblock concrete sleepers for street track in Grenoble 15

10. Rheda City precast sleepers in use on a renewal in Croydon 15

11. New track in The Hague, showing expanding foam injection 16

12. Welded repair to keeper flange – Fleetwood 17

13. Example of street surface reinstatement using concrete blocks and hot poured sealant 18

14. Reinstated grooved rail in Manchester 19

15. Street and segregated track in Montpellier 19

16. Example of traditional drain boxes for grooved rail 20

17. Transverse drain in Montpellier 21

Introduction

This guidance is issued by the Office of Rail Regulation. Following the guidance is not compulsory and you are free to take other action. If you do follow the guidance you will normally be doing enough to comply with the law. Railway inspectors seek to secure compliance with the law and may refer to this guidance as illustrating good practice.

Author:

J R Snowdon, I.Eng, FIET, FIMechE, Chief Engineer, Tramtrack Croydon Ltd (30 April 2008)

At the request of HM Railway Inspectorate and with the assistance of the members of -

• The Light Rail Engineer’s Group

• The ORR Tramway Standards Group

• HM Railway Inspectorate.

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Design requirements for street track

Requirements 1. The primary requirements for any design of tramway track which will be used in the street1 are:

a. suitable load bearing foundations the foundation provided to support the rails should be of a load bearing strength that is sufficient to support both the foreseeable tram and traffic loadings without distress;

b. adequate rail support the rails are adequately supported to allow operation of both trams and foreseeable maintenance vehicles without distress to their foundation or to the surrounding materials;

c. prevention of gauge movements the rails are held to gauge by positive means, sufficient to resist the lateral forces exerted by the wheelsets, by the motion of the vehicle and other highway vehicles;

d. suitable rail fixings anchored securely to the underlying foundation such as to be able to resist any lateral and/or vertical movements induced in the rails as a result of thermal expansion and contraction.

Considerations 2. There are a number of further requirements, principally in regard to the future maintainability of both the track and the street, which also need to be observed, namely:

e. rail maintenance any coatings applied to the rails in order to limit the propagation of stray currents should be consistent with the long term maintenance requirements of the operator and the types of equipment likely to be available to them when there is a need to access and expose the full depth of the rails in order to effect repairs or electrical connections;

f. ducts where the tramway’s cable ducts are constructed alongside the track foundation, a break joint should be provided so as to permit the latter to be excavated with minimal risk of consequential damage to either the ducts or the material in which they are encased. Additionally, where practicable, the cable ducts should be laterally separated from the track slab, particularly through curves and switch & crossing work, so as to allow for subsequent flexibility in the track alignment when renewal works take place. Undertrack crossings should be as near to 90º to the track as is practicable and protected so that the risk of damage when excavation of the track slab is taking place is minimised;

g. under track excavation it should be possible to excavate trenches of moderate width across the width of the trackform without disturbance to the alignment of the rails. Depending upon the rail section chosen, trenches of around 1m in width can normally be spanned by the rails without any additional support;

h. track renewals following works to renew the rails, or alter the alignment or track layout, the track should be capable of operation, under speed restriction if necessary, as soon as is practical, consistent with the needs of restoring the service as soon as possible. A normal expectation is that the track should be usable with the rails supported on temporary blocks or packing pending reinstatement of the underlying foundation layer;

1 Within this document “street” is used as a generic term to describe any road, highway, carriageway or pedestrian area, including grassed track in such environments, where it is necessary to construct track such that the rails are nominally level with the surfacing.

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i. adjacent road level the road surfacing adjacent to the rails to be capable of being adjusted post installation in order to ensure that the effects of rail wear and road surfacing settlement can be compensated such that the road surface can be maintained nominally level with the rail to within the accepted standards (see below);

j. street track surface the materials used to build up the level between and around the rails to restore the ground or street surface should be capable of ready removal and replacement by alternative materials and finishes should the need arise for future aesthetic or highway reasons;

k. current return capacity that the rail cross-section2 should be as large as practicable so that, in combination with the use of cross-bonding cables and/or parallel return cables, the electrical impedance of the traction return path is minimised, thereby minimising the return voltage drop to the traction substations. This will increase the overall energy efficiency of the system, reduce the risk of electric shock from the system and/or reduce the number of substations that are required;

l. rail renewal the rails should be capable of being electrically welded in order to enable – • the effects of side and/or head wear to be made good with the rail in-situ, • new rails to be inserted3, without special requirements as to pre-heating and without causing distress to any components of the track system which are in contact with the rails;

m. duct and equipment access access manholes to the tramway’s cable ducts and other trackside equipment should be positioned such that they can be accessed without significant interruption to either tram or road traffic, or undue risk to staff working in such manholes;

n. rail joint levels where it is necessary to join new rails to existing rails that have side and/or head wear, it is readily possible to lift and/or slew the existing rails so as to allow the contact faces across the joint to be made level4;

o. expansion joints traditional practice in the UK has been for fully embedded grooved rail to be continuously welded and installed without provision for expansion, based upon the relatively limited variation that occurs in the ground temperature and the limited exposure of the rail itself to solar heating. Where it is considered that the provision of an expansion joint would be of benefit in limiting stresses in the rail and/or the rail fastenings, it should be such as to comply with (p) below;

p. rail joints where rails have to be joined mechanically, the minimum standard is a six-bolt fishplate, preferably secured by Huck Bolts (or similar) and with the rail ends butted tightly together. Where relative movement of the two rails is necessary, it is desirable that the joint is scarfed, ie overlapped, in order to lessen the deleterious effects of impact as the tram wheels cross the joint. In all cases, it must be possible to obtain ready access to the fishplates in order that the joint can be maintained;

q. rail transition where it is necessary to change rail sections, particularly between Vignole and Grooved rails, purpose made transition rails should be provided. These should always be located on straight track, if necessary on the approach side of any curve, so that the tram wheels can be properly centred in the gauge and impacts between them and the flared entry to the groove avoided. If this

2 The ruling cross-section is that when the rail is fully worn. 3 The process of replacing worn rail may require the rail being retained to be lifted in order that the running surfaces are maintained level whilst at the same time not causing the trackform to creep downwards into the street construction. 4 Not being able to do this can cause significant difficulties in the renewal of, for example, turnouts that are incorporated into curved track, or can result in the progressive downward migration of the track as successive renewals take place at the same location.

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cannot be guaranteed, even on straight track5, it may be necessary to insert a short length of renewable check rail on both sides of the track immediately ahead of the grooved rail transition, in order that they can take any impacts;

r. groove transition changes from wide to narrow groove rail, eg on the departure side of curves, should also be aligned such that the tram wheels are not presented with a sudden change in lateral alignment. This applies particularly to the inner (or low) rail;

s. electrical return path it must also be remembered that the track, specifically the rails, provide the electrical return circuit from the trams to the substations, and are therefore required to act as efficient electrical conductors in addition to their mechanical role. The standards which relate to this aspect of the track design are set out in the Design Requirements for Stray Current Management, covering the design of the power system as a whole and the measures pertinent to managing the generation of stray current.

5 Typically as a consequence of the use of bogies (or trucks) having independently rotating wheels, which cannot be regarded as having any self-steering properties.

Features of UK second generation track designs 3. All of the second generation tramways built thus far in the UK and Ireland6 are characterised by having track forms in which:

• the rails are encapsulated in an elastic polymer material, which serves as both an electrical insulator (against stray current) and a vibration isolator/damper (against noise and vibration);

• the rails are either held in place solely by virtue of the adhesive properties of the polymer or a combination of holding down bolts bearing on the pre-coated polymer jacket and in-situ cast concrete;

• the rails are mechanically independent of each other (i.e. there are no metal:metal connections between them, or between the metal and the concrete substrate that provide positive control of the gauge);

• the rails are supported on a reinforced concrete slab in which the reinforcement provides both structural integrity and is intended to act as a stray current mitigation measure.

Whilst each of the various designs could be said to have fulfilled the expectations of their designers and constructors, the same cannot always be said regarding those with the responsibility for their maintenance. The passage of time has revealed various shortcomings in relation to their performance and/or maintainability. This is necessarily more apparent with the longer established tramways.

It also has to be remembered that the time pressures on the tramway operator to restore a section of track to operational use are considerably greater than those on the contractor, which factor has not always been properly considered in the overall track design.

Systems with in-situ embedment 4. Descriptions and requirements for suitable load bearing foundations are as follows.

a. Rail support The earliest of the second generation tramways are characterised by the use of reinforced concrete track slab construction with the rails supported in a bed of polymer material, poured in place after the rails had been set to line and level. In each case, the rails are not mechanically fixed either to the slab or to each other.

The slab can be of either shallow or full depth construction, according to whether the concrete is carried to, and forms part of, the road surface (full depth) or is submerged by the street surfacing (shallow depth). With shallow depth slabs, the rails are effectively bonded to the slab only around their foot, and in the absence of any mechanical fixings, have been found to roll laterally under tram loads, particularly in curves. This in turn leads to distress in the surrounding street surfacing, which lacks the strength required to resist these forces.

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6 Metrolink (Manchester), Supertram (Sheffield), Midland Metro, Tramlink (Croydon), NET (Nottingham) and LUAS (Dublin)

Lateral roll of rails causes road surface damage J Brown

The lateral movement of the rail also leads to interference with the wheel:rail interface, to the extent that undesirable levels of flange front and back contact can be generated. Such a system fails to meet Requirement (b), and can be expected in addition to suffer higher levels of rail and wheel wear, as well as increased highway maintenance costs.

This situation does not arise to the same extent where a full depth slab is used, in that the greater strength of the concrete is better able to resist the lateral forces generated in the rail. However, the exposed edges of the concrete slab are liable to crumble under road traffic loads, leading to highway defects for which the tramway operator may be liable. Similar effects can occur with shallow depth slab construction at the interface between the embedment medium and the highway surfacing.

b. Rail welding A common practice on tramways elsewhere in Europe is the longitudinal welding of the rail to make good the effects of wear to both the side and head. With the rail embedded in polymer, this is considerably more difficult due to the problems created by heat build-up, and if, as has commonly been the case, hardened or heat-treated rail has been used, the required preheating can be hard to achieve without causing the chemical decomposition of the polymer, with consequent health hazards to the welders. Without adequate temperature control, there is a high risk of initiating cracks in the rail, leading to breakage and, ultimately, premature renewal at considerably greater cost.

c. Rail break repairs A further consequence of polymer embedment is that it becomes very difficult to gain access to the rail in the event that, for example, a crack requires repairing, or an electrical connection is required, or when a new section requires to be welded in. Generally, whilst the concrete can be broken out using common highway maintenance tools, cutting through the polymer requires an altogether different approach. So far, the only effective methods involve either the use of sharp tools to physically cut it, or the use of very high pressure water jetting. Renewal generally requires the road surface to be saw cut on either side of the rail so that the rail can then be pulled out of the road. Depending upon how well the rail and concrete were cleaned prior to the embedment being poured in the first place, the bond between the two can be sufficient to cause small but significant quantities of concrete to be pulled away from the slab. Further, it is still necessary to excavate a significant size hole at each end of the section being renewed in order to allow the welds to be made to the existing rails.

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Welding a rail joint M Howard

A secondary problem is that the rail, with the polymer still attached, has a zero scrap value and can be difficult to dispose of.

Systems using pre-cast embedment 5. Descriptions and requirements for systems using pre-cast embedment are as follows.

d. Pre-coated rail break welding As an alternative to the above, some systems have been constructed using rail to which the polymer jacket has been applied in a factory environment, so that the amount of in-situ work, which is always subject to weather conditions, is reduced to the on-site encapsulation of the rail ends where they have been welded together, and to switch and crossing work. This technique also facilitates a much higher degree of control over the relative levels of the rail head and the surrounding street surface in that the usual method of installation is to set the rails to line and level on the previously cast concrete slab and then make up the surrounding street to the level of the rails. Crushed stone can be added to the top/exposed surface of the polymer to aid skid resistance.

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ALH6 polymer pre-coated SEI 41GP grooved rail NTC

However, once installed, the same problems can exist in terms of the difficulty in accessing and welding the rail itself as with the in-situ embedded systems, for the same reasons. The extent to which this can be a problem will depend on the polymer used, the steel grade, particularly if significant preheating is required, and the ability to achieve adequate heat dissipation during welding processes.

Generic problems with concrete slab construction 6. The generic problems associated with concrete slab construction are as follows.

e. Road level Significant problems emerged early on with level differences between the rails and the adjacent concrete, sometimes well over the limits of what could be considered compliant with either the 1870 Tramways Act interpretation of “level” or the more recent redefinition that resulted from the legal case Roe vs. Sheffield Supertram, which had resulted primarily for the inherent differences in construction accuracy for the vertical alignment of the concrete work and the rails, and were blamed for a number of instances involving loss of control of road vehicles.

Pre-coated rail installed on concrete slab D Keay

f. Level resolution To a large extent, the pre-coated rail systems were designed to overcome this problem by ensuring that the rails could be laid first, and the street surfacing subsequently laid by reference to the rail level. However, the same principles can also be followed using traditional tramway track construction, so long as the surfacing is laid after the rails have been fixed, as was normal practice with traditional street track construction.

g. Current track alteration practice It has also become practice in the UK to build the track on a reinforced concrete slab, with the concrete in at least some cases being of a high strength grade (at least C40) so that (i) the slab can act as a bridge across trenches up to 2m in width, and

(b) the reinforcement can act as a collector mat for intercepting and redirecting stray currents from the

traction return circuit.

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As a consequence, it becomes much more difficult to either modify the track to accept tiebars or direct fixings to the slab, or to alter the alignment without first breaking out the slab entirely. That task is also made difficult by the high strength of the concrete employed and the amount of reinforcement present, and can thus represent a major cost and time element in any track renewal works, the latter giving rise to high risks of possession over-runs.

h. Track replacement difficulties Rail replacement has exposed the difficulties of access through the track slab, in that although the rail can be released along its length by saw cutting the concrete, outside of the polymer, it is still necessary to excavate access holes around and below the rail at the cut ends, and to clean the remaining ends of polymer before welding.

Generic problems with floating rail construction 7. The generic problems associated with floating rail construction are as follows.

i. Polymer only supported rail allows too much movement Compared with traditional forms of tramway track construction, the extent to which the rails can move when they are supported solely in polymer, especially the softer grades, is liable to cause problems with track drains, as well as any other equipment, such as connection boxes and point mechanisms, that are attached to the rails, and non-welded rail joints. The relative movements between the two are liable to result in failure and subsequent mechanical deterioration, whilst fishplated joints, particularly where only four bolts are used, are inadequately supported and once some wear has taken place on the fishing surfaces, will progressively deteriorate. At the same time, where the rails have been embedded in polymer, even if only partly, it becomes next to impossible to undertake any basic maintenance work on the joint unless the polymer is removed first. Even then, unless attended to as soon as looseness has become visible, it is difficult to recover the situation as a result of the damage that has started to occur to the fishing surfaces of both the rail and the fishplate. The failure of such joints in Switch & Crossing work is also liable to cause consequential damage to major components, such as the switch or crossing legs, which are then expensive to repair, given the complications introduced by any rail embedment. Where switches are located in street areas where they are run across by other road traffic, particularly goods vehicles and buses, the mechanical security of the point mechanism is prejudiced as a result of the relative lack of support. The case containing the mechanism is usually supported on lugs welded to the rails, with the result its vertical movement under road traffic loads can be sufficient, over time to cause these lugs to break. Because they are contained within the embedment, they cannot be inspected without excavation, and first sign of breakage is when the whole mechanism case becomes loose in the road.

j. In-situ adjustment Whenever it becomes necessary to replace sections of rail with new, it is essential to ensure that the head and gauge or keeper faces (as appropriate) are lined up across the joint. In the vertical direction, it is usual to lift the remaining old rail to meet the head of the new, whilst laterally it is necessary to slew the old rail. However, when the rail is encased in polymer and effectively bonded to and/or constrained by the surrounding concrete, there is very little latitude to do this without considerable additional excavation. Consequently, it becomes easier to set the new rail to line up with the old, with the effect that as the latter is then replaced, the vertical and horizontal alignment starts to drift, with potentially significant effects.

k. Noise and vibration Once the rail is supported on elastic materials, eg polymer, it becomes a mass/spring system in own right. At the same time, it is usual, with modern trams, for the tyres to be resiliently mounted on the wheel centres, which are then resiliently coupled to the bogie frame and car body in turn. The result, particularly if the support for the rail is relatively elastic, is that both the wheel rim and the rail can be set into oscillation as a result of either dynamic interaction or external inputs such

as a railhead discontinuity at a joint. This in turn becomes a generator of further excitation as well as noise and rail corrugation. From observation, it is evident that the firmer the rail support, the less likely this is to occur. To an extent, some of this, particularly the higher frequencies, can be attenuated by means of dampers fitted to the wheel, or the wheel rim. However, the resonant modes are complex and cannot always be controlled in all respects.

Solutions capable of meeting the requirements 8. Producing a track form which will meet these requirements requires three fundamental elements in its design, namely:-

• a foundation layer, sufficient to transmit the loads imposed on the rails into the underlying substrate, ie the subsoil,

• rails, of sufficient weight to both support the trams and provide a sufficient return path for the electric traction current,

• means for maintaining the rails to the correct gauge and alignment under the vertical and horizontal loads imposed upon them.

l. Foundation As with the highway itself, some means is needed to spread the weight of the vehicle such that neither it nor the surface it is standing on will sink into the underlying ground. For railways, this was accomplished by supporting the rails on sleepers and ballast such that pressure exerted on the ground was low enough to be borne by the subgrade. Similar techniques were adopted for the early street railways, but with the passage of time and heavier vehicles, were ultimately found wanting, with decay of the otherwise inaccessible sleepers being a significant factor. By the start of the electric tramway era, c.1890-1900, it had became more normal to set the rails directly on to a continuous concrete bed as a better means of support. The rails were held to gauge by steel tiebars, and anchored to the concrete, frequently by short lengths of old rail, laid transversely and secured tightly to the new running rails. The latter are necessary as a means of ensuring that the rails remain in place even under thermal stress, since they are neither pre-stressed (as in modern CWR practice) nor provided with expansion joints, it being normal to either weld or close joint the rail ends. The concrete foundation was simply laid up to the bottom of the rails, without any internal reinforcement.

Tie bar arrangement of rails as used on the Blackpool tramway

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An example of traditional track construction in Graz in 2004

This method for laying street tramway track is still in widespread use across Europe and has changed little other than by way of the insertion of resilient elements between the rail and the concrete, and the introduction of precast concrete sleepers which are then cast into the slab. In some instances, a single layer of reinforcement is used, but only as an anti-cracking measure in the same manner as for concrete highway construction.

There are also a number of systems that were developed in the latter part of the 20th century, principally in Eastern Europe, where the trackbed is formed of precast concrete slabs which are laid on to a prepared subgrade, with the rails then inserted into slots cast in the top surface and retained by rubber strips. These systems are not suited to other than plain track, and require an accurately laid sub-base to support the slabs, as there is no scope for subsequent adjustment.

m. Rail weight Although not essential, it has long been established practice in Europe and elsewhere for tramway track to be laid using grooved rail. There are a number of different sections available, largely as a result of historical and national differences however, consistent with Requirement (k) above, it is preferable to adopt as large a section as is practicable. It is also preferable from a maintenance viewpoint to adopt a section which is in large scale use, and thus readily available from the rolling mills. As one example, the German Ri60N section fulfils these requirements, with the complementary Ri59N section (having a wider groove) for use on curves of less than 100m radius.

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Grooved rail profiles

n. Gauge and alignment Where the rails are laid on a plain concrete slab, as per traditional methods, it is necessary to provide some means whereby they are (a) held to the required gauge and (b) tied so as to resist the overturning forces induced by the action of the wheelsets on curves7. The traditional, and still current, method is to use steel tiebars, usually fabricated from flat or round bar construction and bolted to the rail webs at suitable intervals, typically every 2m on straight track, 1.5m or less on curves of less than 150m radius. This method also has the advantage, useful during maintenance activities, that the track can remain safely usable, albeit under restriction, even without the underlying concrete in place, with the rails simply supported on packing blocks. A modern alternative, adapted from the methods used to construct the slab tracks used for high speed railway lines, is to attach the rails to precast concrete sleepers, or sleeper blocks, which after being lined and levelled are then embedded in the mass concrete foundation slab. To facilitate this, these sleepers are only partially cast so that their internal reinforcement cage is exposed and becomes embedded in the slab. Such systems have the benefit of positively holding the rails to gauge and restraining them against twisting under wheel steering forces on curves. Gauge tiebars are not required, the function being provided by the sleepers, and replacement is considerably simplified by comparison with the polymer embedded track systems, rails can be readily unclipped from the sleepers to facilitate replacement.

Page 14 of 21 7 On typical street tramway curves of <50m radius, these can be very considerable, in the order of 30-40kN.

Twinblock concrete sleepers for street track in Grenoble E Hollis

Rheda City precast sleepers in use on a renewal in Croydon J Snowdon

Irrespective of the method used, it is beneficial to place a layer of resilient material between the rail foot and the concrete in order to provide some cushioning against vibration transmission and to avoid the fretting action between the rail and the concrete which would otherwise occur under repeated loading.

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New track in The Hague, showing (nearest) expanding foam injected into the gap between the rail and the concrete.

o. Rail hardness Rails are available in both normal (700 / R200 grade) and heat-treated (900 / R260** grade8) or alloy steels (typically 1100 / R340** grade), the latter intended to provide greater wear resistance and thus longer life. Whilst there are some attractions to using harder rails on curves that are expected to receive heavy wear, their life is still significantly less than the same rails on plain track. As an alternative to the considerable cost of replacing such rails, it has become a common practice to rebuild the side and/or head wear by welding. Whilst readily practicable on normal R200 grade rail, careful control of the welding process is required for the harder rails if the risk of cracking is to be avoided. This requires either preheating or very careful control of the welding process, usually by automated techniques, to ensure that cracks do not develop in the heat affected zones behind the welds and subsequently propagate through the rail section. It should be borne in mind that, because the rail is fully embedded, it is not always possible to monitor the progress of any crack beneath the visible surface of the rail head. It must also be borne in mind that excessive rises in the rail temperature can exceed the safe limits for the polymer, causing both degeneration and exposing workers to hazardous fumes and fire risk.

Page 16 of 21 8 BS EN 14811 lists steel grades as both Rxxx & RxxxGHT, the latter designating heat treated steels.

Welded repair to keeper flange - Fleetwood

For this reason it is the practice of some of the well-established European systems that normal (700 / R200) grade rail is used in the high wear areas, if not throughout the system. Once the initial wear has taken place, it is made good by welding using hard wearing materials, thus obtaining the wear characteristics of the higher grade steels but retaining the advantages of the weldability of the normal rail. As these wear, the hard facings can be renewed several times before wholesale renewal of the rail becomes necessary. As a rule, the costs of replacement normally outweigh the costs of repair by welding many times over, reducing the life cycle cost.

p. Wheel hardness versus rail hardness Consideration must also be given to the relative hardnesses of both the rail and the vehicle tyres, particularly in areas where sliding (as against rolling) action takes place. This normally occurs in the curves, and experience has been that there should be a distinct difference between the hardness of the two components; empirical evidence would indicate that where the rail and tyre are of comparable hardness significant roughening of the surfaces can occur, resulting in an increased risk of derailment, as well as higher wear.

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q. Surface reinstatement The level of any surfacing adjacent to the rail head should be such that the tram wheels, particularly in a fully worn condition, do not run on the surfacing such as to cause damage, as well as unnecessary noise and vibration. Where possible, the surfacing should be kept below the top of the rail head, subject to any limitations as regards the safety of other road users and/or pedestrians. Depending upon whether the finished track is in the carriageway (shared) or segregated, the surface between and outside of the rails is built up using a combination of mass concrete and normal bituminous street surfacing materials, sand- or stone-bedded blockwork, crushed stone or, if appropriate, earth and grass. Whichever method is chosen, it is necessary to consider how it will be maintained in the future, both from the point of view of reinstatement following maintenance and the issues of controlling the height of the rail head relative to the road surface. Experience with bituminous materials has shown that these can be difficult to lay accurately and with the proper consolidation over relatively narrow widths, such as alongside the outside of the rails and in turnouts.

Further, such materials are by their nature susceptible to flow under repeated loadings by road vehicles following the same track. This can result in the tram rail becoming significantly proud of the adjacent surfacing and vice versa. Buses present special difficulties in this regard as a result of weight and suspension characteristics, particularly where they routinely wait in shared tram and bus lanes, such as at traffic signals and stops. Alternatively, there are foreseeable advantages to reinstating the road surface around the rails using concrete blocks9, in that these can relatively easily be adjusted to be level with the rails when laid and subsequently as the rails wear. It is a technique used on various tramways in Europe with no apparent problems, with slabs typically ranging from 400mm square to the full width of the “four-foot” and 2-2.5m in length. The technique is essentially only a modern day equivalent of the granite and/or wooden setts used on the first generation tramways.

An example of street surface reinstatement using concrete blocks, with hot poured sealant between blocks and rail

Page 18 of 21 9 Not to be confused with the small concrete paving bricks used in, typically, pedestrian and non-trafficked areas.

Rail concreted in place M Howard

A third option, subject to the approval of the street authority, is to surface using concrete. This should, as with any concrete used to infill between the top of the slab and any bituminous surfacing, be of a lower strength such that it can easily be excavated as and when it is necessary to access the rails and their fixings. This does, however, carry the disadvantage that the edges of the concrete next to the rail edge sealant are liable to crumble over time.

For track which is not shared with road vehicles, the space in between the rails, and between the rails and the edges of the track can be infilled with a variety of materials, ranging from crushed stone to earth sown with grass, or compacted sand on which concrete or stone blockwork is set. Where the infill material is porous, appropriate and adequate drainage should be provided to the section between the rails, or between tracks, by the inclusion of drains in the foundation slab at the time of construction.

Street and segregated track in Montpellier E Hollis

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r. Drainage In addition to any provision made for the drainage of surface water from the street as a whole, arrangements should also be made to drain water from the rail grooves at appropriate intervals and/or locations. These should be on straight track as far as is possible and should not, unless there is no other option, be located in curves of less than 50m radius. The drainage slots should be of sufficient size not to become easily blocked by street detritus and/or sand dropped by trams, and should be formed by machining, with generous radii at the corners in order to avoid stress concentrations under lateral loadings.

An example of traditional drain boxes for grooved rail prior to concreting in. J Snowdon

Examples of typical detritus that will end up in rail drainage slots include - - food remains from fast food outlets, typically packaging and chicken bones - disposable pens, of the sort found in catalogue stores and betting shops - coffee stirrers - plastic drinks bottles and cans, which lodge in the groove and become crushed

all of which may not necessarily block the drain slot by themselves, but which, once lodged, then provide sufficient obstruction for other detritus, including tram sand, to collect and ultimately block the slot.

It is also common practice on established tramways to install a continuous drain along the centre line of each track, into which both the rails, the top of the track slab, if covered by a porous material eg grass or stone, and point mechanism boxes can drain. This is in turn drained to the highway drainage system at suitable intervals, thereby minimising the number of under-rail pipe connections needed. It also facilitates the use of transverse drainage gulleys between the rails in order to drain that part of the highway, which can otherwise tend to act as a wide channel.

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Transverse drain in Montpellier E Hollis

Drainage water should be led into purpose made drain boxes bolted to the rail web before being conducted into the street drainage system. The size, number and capacity of the drainage boxes at any location should be sufficient to ensure effective drainage under all reasonable conditions of rainfall and maintenance. These boxes should incorporate a silt trap, sufficient to allow for both normal detritus and the additional sand which may be dropped by the trams, as well as facilities for rodding and/or flushing through the drainage connections leading from them. Connections to the street drainage system should be of adequate size, having regard to the fact that the rail grooves often act as drainage channels for a significantly greater area than the street in the immediate vicinity.

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Technology Review


Control Sheet

CONTROL SHEET

Project/Proposal Name: WEST OF ENGLAND RAPID TRANSIT Document Title: Technology Review Client Contract/Project Number: SDG Project/Proposal Number: 207514-L

ISSUE HISTORY

REVIEW Originator: Ian Sproul Other Contributors: Chris Ferrary, Dick Dapre, Peter Armitage Review By: Print: Peter Armitage Sign:

DISTRIBUTION Clients: Steer Davies Gleave:

Issue No. Date Details 1.0 14 July 2008 Draft to officer team for comment only 2.0 25 July 2008 Draft for internal client comment only 3.0 30 July 2008 Draft for internal client comment only 4.0 22 September 2008 Final Report

WEST OF ENGLAND RAPID TRANSIT · 2019. 6. 9. · The proposed BRT network consists of a number of...

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