Under Sleeper Pads on the Ofoten Line Bjørn G. Larsen, Infrastructure Division and Alf Helge Løhren, Technology Jernbaneverket

19th Nordic Seminar on Railway Technology 2016 Luleå, Sweden

Content

• Test Site

• Inspection and Observations after 100 MBT

• Influence on Track Geometry Durability

• Conclusions

• Further Works

Test Site

• Location:

Straumsnes station, Track 2

Km 13,157 – km 13,483 (326 m)

• Curvature: Rmin = 322 m / Cant 44 mm

• Gradient: 13 - 14 ‰

• Speed:

50 km/h (Equilibrium speed to loaded

iron ore trains)

60 km/h (Empty iron ore trains)

70 km/h (All other trains)

• Max axle load: 30 tons

• Traffic load: Ca. 100 MGT after 4 years

Test Site - Superstructure

• Track 2 renewed in 2012

• Rail profile: 60E1

• Fastening: Pandrol Fastclip FC/FE

• Concrete sleepers:

NSB 96 without USP (100 sleepers)

JBV60 with USP (567 sleepers)

Sleeper space 520 mm

• Crushed stone ballast:

Fraction 31.5 – 50 mm

Thickness under sleeper: ~ 300 mm

Under Sleeper Pads - USP

• Manufacturer: Getzner

• Product data:

Sylomer® Under Sleeper Pad

SLB 2210

Elastoplastic material (Polyurethan) for

optimal ballast fixation

Bedding Modulus: Cstat = 0.22 N/mm3

(Static secant stiffness)

Thickness: 10 mm

Weight: Approx. 4.2 kg/m2

Form of delivery: 2 semi-parts per

sleeper

Test Site Straumsnes Station –

Visual Inspection of Sleepers

100 sleepers without USP

100 sleepers

with USP

467 sleepers with USP

3 sleepers with USP were

inspected

3 sleepers without USP

were inspected

Track Geometry Observation Distance in This Presentation

Visual Inspection of Sleepers at km 13,400 and km 13,350

3 Sleepers without USP

3 Sleepers with USP

Sleepers 11 and 12 without USP

Sleeper 13 without USP

Inspected Sleepers without USP

• 3 sleepers NSB 95, Ø2009; No. 11, 12 and 13

• No cracks

• Slightly dust under sleeper 12, no dust on the other sleepers

• Little rugged surface, more or less like new sleepers

• The edges on the underside not or very little rounded or

damaged

• Conclusion of Visual Observation:

The concrete sleepers without USP are insignificant worn

and damaged after 100 MGT.

Sleeper SM1 with USP

Sleeper SM2 with USP

Sleeper SM3 with USP

Concrete Sleeper

USP SLB 2210

Inspected Sleepers with USP

• 3 sleepers JBV60 S2012; No. SM1, SM2 and SM3

• Small impressions 2 – 5 mm in the USP from ballast stones

• Some small tears in SM2 and SM3

• A few tears on the edge of SM2

• USP has loosened from the concrete in a short distance on SM1,

otherwise good fixing for the mounting mesh onto the concrete

• Negligible damaged on the concrete edges on the sleepers undersides

• Conclusion of Visual Observation:

Insignificant wear and damage on the USP or sleepers after 100 MGT.

Visual Inspection of Ballast under Sleepers without USP

Visual Inspection of Ballast under Sleepers with USP

Assessment of Ballast Reduction/Contamination

• Sleepers without USP:

Little size reduction of the ballast stones

Little contamination of the ballast

• Sleepers with USP:

No or very little size reduction of the ballast stones

Little contamination of the ballast

• Conclusion of Visual Observation:

Negligible difference in ballast reduction and

contamination under sleepers without and with USP after

100 MGT

Test Site Straumsnes station, Ofoten Line

Sleepers without USP

Test Site Straumsnes station, Ofoten Line

Sleepers without USP

Test Site Straumsnes station, Ofoten Line

Sleepers without USP

Test Site Straumsnes station, Ofoten Line

• Comparison of track geometry defects

tendency in track without and with USP:

No difference in develpoment of

increased track gauge

No difference in development of

alignment defects

The track level may have a tendency to

change more the first years after sleeper

installation, if there are USP?

No difference in development of twists

Sleepers

without USP

Sleepers

without USP

Conclusions:

• Even inspection samples are limited, following visual

observations have been done after 100 MGT:

Insignificant wear and damage on the sleepers without

USP

Insignificant wear and damage on the sleepers with USP

and on the USP itself

Negligible difference in ballast reduction and

contamination under sleepers without and with USP

• At this stage it is impossible to make any final decision about

the influence of USP on ballast degradation and track

geometry durability on the Ofoten line after 100 MGT.

Further Works:

• New inspection of sleepers, USP and ballast after 200 MGT

• Comparison of later track geometry diagrams

• Planning of test program with use of “Smart Sleepers”

Censors to measure loads, tensions and bending

moments in sleepers without and with USP

Thank You for Your Attention!