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: R min = 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: C stat = 0.22 N/mm 3 (Static secant stiffness) Thickness: 10 mm Weight: Approx. 4.2 kg/m 2 Form of delivery: 2 semi-parts per sleeper
Test Site Straumsnes Station Visual Inspection of Sleepers 467 sleepers with USP 100 sleepers without USP 3 sleepers with USP were inspected 100 sleepers with USP 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 with USP 3 Sleepers without 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
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 Sleepers without USP 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
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!