TOWER CRANE INSPECTIONS Presentation Overview · Presentation Overview • Background of Coast...

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Presented by Mike Heacock

Coast Crane Company

TOWER CRANE INSPECTIONSPresentation Overview

• Background of Coast Crane and Mike Heacock• Review common tower crane types• Pre-delivery inspections for new tower cranes. Required

by manufacturers• Storage and transportation of cranes and components• Preassembly and jobsite delivery inspections• On site preparations, inspections, calibrations and

orientation• Periodic inspections on site

C O A S T C R A N E C O M P A N Y

Background

• Graduate of U of W in Construction Management• 15 years of experience working in the crane industry• 10 years working with tower cranes• While at Sunnen Crane Service I helped pioneer the use

of self erecting tower cranes in the Northwest• Currently the Tower Crane Division Manager for Coast

Crane Company


Coast Crane Company Background• Elite Dealer for Manitowoc Crane Group – Territory

includes California, Oregon, Washington, British Columbia, Alaska- Manitowoc Crawler Cranes- Grove Mobile Cranes- National Boom Trucks- Potain Tower Cranes

- #1 Self Erecting Tower Crane Dealer in North America- 1st MDT City Crane Dealer for MCG

• Dealer for Comansa Tower Cranes for California

• Dealer for Tadano Tractor Mounted Boom Trucks


Coast Crane Company• Coast Crane’s Tower Crane Fleet

- Approximately 100 Units2/3 of fleet is Self Erecting Cranes1/3 of fleet is Hammer Head Cranes


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Self Erecting Tower Cranes


Most self erecting cranes swing at the bottom of the tower

Self erecting cranes are free standing on an outrigger type base. Drive bogies can be attached so the crane can move around a job site on rails.

As their name implies, self erecting cranes have the ability to completely assemble themselves without the aid of an additional crane. This significantly reduces the erect / disassembly cost.

Self erecting cranes can be operated from a cab located at the top of the crane but quite often they are operated from the ground via wireless remote control.

The tower of most self erecting cranes turns with the jib. Some towers telescope out to predetermined heights giving the user multiple tower heights to choose from. Other towers fold half way up and only allow one tower height to work at.

Counterweight

Back stay or back pendant

Pendants

JibTrolley

TOPLESS HAMMER HEADTRADITIONAL HAMMER HEAD

No tower top and pendants reduces the topless crane’s overall height. This is advantageous on multi-crane projects or around airports. The jib also does not have to be completely assembled on the ground because it does not rely on pendants for support.

Hammer Head cranes slew at the top of the tower

PendantsTower Top

Counter Jib

Counterweight

Trolley

Hammer head cranes require an additional crane for erection / disassembly. Pieces are erected individually or as component groups.

Operators typically control the crane from a cab at the top of the crane which swings with the jib.

Counterweight

Cranes equipped with self climbing gear have the ability to add tower sections under their own power. This enables the crane to be erected at a lower tower height and grow with the building.

TowerTower sections range in length but are generally 15’-20’ tall and can be erected either one at a time or in multi-section groups to save erection time on site.

Static baseThese bases require a large concrete footing but only require enough space for the tower. These bases work well in elevator shafts or where space is limited.

Ballasted Cross Frame BaseThese bases require a smaller concrete footing but require enough space for the cross frame and ballast. These bases work well outside the building footprint. These bases require extra assembly time and trucking. Traveling bogies can be attached and the crane can move around a job site on rails.

Counter Jib

Hammer Head Tower Cranes


Jib

Luffing Jib Tower Crane

JibUnlike other tower cranes which utilize a trolley system, the jib on luffing tower cranes is configured like a lattice boom mobile or crawler crane. The crane uses a gantry and boom hoist to raise and lower the boom with the load block always suspended from the jib / boom tip.

PendantBoom Hoist Bridle

Fixed Counterweight

Swinging CounterweightMany luffing tower cranes have both fixed and swinging counterweights. Swinging counterweights move away from the center of rotation as the operator booms down and towards the center of rotation as the operator booms up. Greater maximum radius capacities can be achieved with this system.

Gantry

Machinery Platform

TowerTower sections range in length but are generally 15’-20’ tall and can be erected either one at a time or in multi-section groups to save erection time on site.

Cranes equipped with self climbing gear have the ability to add tower sections under their own power. This enables the crane to be erected at a lower tower height and grow with the building.

Most luffing cranes slew at the top of the tower

BaseLuffing tower cranes can be put on both static and ballasted cross frame bases. Static bases (as shown) require only enough room for the tower but have a large concrete footing. These bases work well in elevator shafts or where space is limited. Ballasted cross frame bases (not shown) require smaller concrete footings but occupy much more room and are generally used outside the building footprint. Traveling bogies can be attached and the crane can move around a job site on rails.

Luffing tower cranes are advantageous when working in cities or other areas where buildings or other structures would obstruct 360° swing of a traditional tower crane. Luffing cranes are also useful on multi-crane projects where hammerhead crane jibs would not have clearance. Drawbacks to luffing jib cranes are high monthly rental rates and erect / disassembly cost.

Operators typically control the crane from a cab at the top of the crane which swings with the jib.


Pre-delivery Inspections for New Cranes • New crane components are unloaded from containers or

trucks– Inspected for shipping damage– All components are assembled (ie jib sections pinned together)

& then disassembled into subassemblies for shipping to the jobsite

– All electrical components are connected, energized and tested as a complete unit

• Testing checks for electrical shipping damages that may not be noticeable from a visual inspection

• Self erecting tower cranes are erected in our yard.– The cranes are function tested and load tested both static and

dynamically to loads that exceed on site testing (required by manufacturer)


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Storage and Transportation• To maintain integrity of tower crane components, and

prolong the life of these expensive tools, tower cranes and their components must be stored, transported and handled properly to ensure they stay safe for a long period of time.STORAGE IN YARD

• Components must always be bunked on wood or steel blocking to keep the components from being damaged

C O A S T C R A N E C O M P A N Y C O A S T C R A N E C O M P A N Y

Storage and Transportation• Components must also be stored in a manner so water

cannot pool in the surface of the components promoting corrosion

• Some electrical components should be either covered or stored indoors to ensure their longevity by reducing their exposure to moisture.

Storage and TransportationRIGGING & HANDLING

• Most manufacturers supply information on proper lift points or methods.

• These instructions must be followed in order to ensure the components are not damaged while handling the crane components.

C O A S T C R A N E C O M P A N Y C O A S T C R A N E C O M P A N Y

Storage and TransportationTRANSPORTATION

• Chain tie downs should always be avoided for securing equipment on the trailer. If possible, use nylon straps to secure the loads. Chain must never be used to secure lattice type equipment (ie. jib, tower etc.)

• If chains must be used on non-lattice equipment, softener must be placed between the chain and the component being tied down to ensure the chain links do not dig into the component during transportation.

• All components loaded on trucks should be able to sit on the trailer without being tied down or rigged to a crane.

Pre-assembly Inspection• Performed prior to shipment to project site• Must be performed by competent person• Documentation must be kept. See sample documents

for periodic checklist for hammer head tower cranesSUMMRAY OF INSPECTIONS

• Visual inspection of structural components– Looking for damaged lacings, cracked welds, bent or

damaged components– Components with suspect welds or cracks must be

NDT tested– All repairs must be made by a certified welder

experienced in performing repairs of this type– All materials must either be supplied by manufacturer

or must be approved by manufacturer


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Pre-assembly Inspection


SUMMRAY OF INSPECTIONS (cont)• Clean and Inspect all pins and bolts that are removed

during assembly / disassembly – Cleaning should be done with solvent or other

degreaser– Cleaning with a wire brush or wheel should be

avoided as it may remove protective coatings and over time reduce the diameter of the pin or bolt.

– Pins or bolts with suspect cracks must be NDT tested and replaced if cracks are present


SAFETY ITEMS• Check the condition and installation of all ladders

platforms, ladders and handrails• Check to see all warning signs and safety decals are in

good condition and in their proper place• Check to see the fire extinguisher, operating manual and

log book are in the cabin or operators station


WIRE ROPE• Inspect wire rope as per ANSI

B30.3 instructions for tower cranes

• Damaged wire rope must be replaced or shortened by removing the damaged section of rope

• Proper procedures must be followed by an experience individual when shortening wire rope (Cutting with an oxy-acetylene torch is generally not an approved method for shortening tower crane hoist ropes)




Pre-assembly InspectionELECTRICAL COMPONENTS

• The inspections required will vary by model and manufacturer

• Primary components– Electrical slip ring – clean & inspect for abnormal wear– Cabin / remote controls – clean & check functions– Limit switches – check condition– Motors – test conditions of windings (megger test)

- check brake adjustments, pads or linings– Electrical supply cable – inspect for damage (ie. cuts, cracks etc) - Electrical cabinet components - check for signs of wear on

contactors, timers, etc.

On Site• Customer responsibilities

Foundation– Engineer must evaluate soil (self erecting crane) or design

concrete footing– Provide survey instrument and qualified person to plumb the

base tower section when it is set– Break concrete cylinder from footing prior to erecting tower crane

Industry Standard for tower crane plumbtolerance is L/500

example: Δ=96”/500Δ=.192” max.


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On SiteAssembly / Disassembly– Provide unobstructed work area for assembly of components– Restrict access for other trades to assembly areas and areas

under overhead work– Have licensed electrician on site to connect or disconnect the

crane to the electrical and grounding service

• Turnover report (see sample documents)– Technician and operator checklist which double checks all

components and systems of the crane have been properly assembled

• In Service Certification (load test report – see sample document)– Functional tests of the crane are performed checking all systems– Calibration of all movement limits and capacity limits as well as

testing the support structure or footing


On Site

• OPERATOR ORIENTATION• It is extremely important that all operators (regardless of

qualifications) review the functions, features and safety items of each tower crane with a qualified crane technician


Periodic Inspections On Site• Operator inspections (see sample documents)

– Daily logbook – visual inspections and functional checks of crane systems

– Weekly logbook – detailed visual inspections and routine maintenance

• Coast Crane Inspections (see sample documents)– Periodic 3 month – visual inspections and routine adjustments of

crane systems– Annual – detailed visual inspections and major adjustments and

checks of crane systems


TOWER CRANE INSPECTIONS Presentation Overview · Presentation Overview • Background of Coast...

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