Why NR60 Mk2 S&C?
Strengthening the case for NR60 Mk2 S&C layouts NR60 MK2 from pilot site to ‘business as usual’
Ian Bostock, Principal Engineer (S&C)
Providing technical leadership Ian Bostock : Introduction
Principal Engineer (S&C) S&C Engineering Team, Technical Authority, Network Rail On secondment to Supply Chain Operations, Route Services, Network Rail
25 years in S&C – Started working for Balfour Beatty 15 years in the national engineering team (Network Rail)
Page 2 NR60 MK2: The Journey & The Challenge
The Journey NR60 MK2 development 2017 Thirsk pilot site 2019 3 more sites 2020-2021 business as usual The future
The Challenge Justify NR60 Mk2 as the right solution Manage the change and differences Justify and manage the associated costs
Page 3 NR60 S&C NR60 Mk2 development
Providing technical leadership CEN 60 S&C – What is it?
CEN 60 rail section – Taller and stiffer than CEN56 rail 650mm nominal bearer spacing (vs 710 for Vertical S&C) Inclined running rails & 1435mm gauge – better wheel rail interaction
Widely used in mainline railways throughout Europe and the world
Page 5 CEN60 S&C - benefits
In relation to previous UK CEN56/54 Vertical designs it offers:
• A stiffer track form • reduced point loading on the ballast and formation • Better support for switches, crossings and POE • Lower bending stresses in the rail • Less rail defects • Better wheel rail interaction • Less RCF • Better steering characteristics • Better vehicle stability
Page 6 CEN 60 S&C – A potted history 1
• RT60 developed in late 1990’s (Railtrack) • 4 designs • Edgar Allen • Balfour Beatty • Corus Cogifer • VAE • Manufacturer specific components • Common geometry and crossing footprint • Geometry differs from CEN56 Vertical designs • Higher cant deficiency limit
Page 7 CEN 60 S&C – A potted history 2
• NR60 S&C was introduced in 2005-2006 • Network Rail bought the rights to the Edgar Allen RT60 design • A few minor design changes were made • Hy-drive was adopted as the standard POE • NR60 (MK1) Challenges • Cost • Geometry footprint compatibility • Crossing issues • Switch wear and damage (Trailing moves)
Page 8 NR60 MK2 Development – Geometry (RE/PW/4299)
Layout Geometry is compatible with NR56V Geometry changes slightly with change in gauge and rail head width
Switch geometry for B, C, D, E switches (Secant geometry) is almost identical to NR56V. C switch has a slight modification to reduce the switch entry angle. Switch geometry for longer switches is different. Tangential geometry is used, as with the older HV & HVS switches. This is common practice in Europe and gives a smoother transition on the diverging route.
We avoided the use of the clothoid used on NR60 Mk1 switches The cant deficiency figures are lower than NR60 MK1 (90-95mm) The switch entry is carefully managed
Page 9 Switch geometry and analysis
B- E Intersecting or Secant
F- G Tangential
Page 10 Switch geometry – switch entry
Switch toe abrupt change in cant def Equivalent rate of change BS EN 13803:2017 Andrew Turner Senior Engineer (S&C) Network Rail
Page 11 NR60 Mk2 Development switches and POE
Switch flexure analysis has been around for many years. Learning has increased more recently. Loads and displacements when the switch is opened (bent or flexed)
Points Operating Equipment Evolution of existing technology In Bearer Clamplock Mk3 Tubular supplementary drive Testing to confirm the analysis & establish head room
Page 12 NR60 Mk2 Development - POE
IBCL Mk3 with Hy-drive IBCL Mk3 & tubular supplementary drive All switch sizes – focus on long
B, C, D & E switches switches Page 13 NR60 Mk2 Development – Cast Crossings
Last years PWI W&W presentation
CEN60 cast crossings have a longer life, on average There is a lower risk of fatigue cracking from the base
NR60 MK2 crossings: • Improved profile, wheel transfer • Lower dip angle and impact forces (much quieter) • More resilient crossing through design and stress analysis
Page 14 NR60 Mk2 Development - Layouts
SeeSeeSee
See NR/GN/TRK/065 for more details
Page 15 NR60 MK2 Developments -layouts
• Bearer (modular) joints with Vossloh NG screws and green dowels • Switch toe position indicator – a hole in the stock rail (eliminates ball and claw) • No stress transfer blocks at heel • Direct fix cranks. The nominal construction height is consistent throughout
Page 16 NR60 MK2 Pilot site to BAU
Providing technical leadership NR60 MK2 introduction
Thirsk Installed April 2017 ECML 125mph through line speed C 13 Transition emergency fast- fast crossover (Trailing) D15 Transition crossover down slow-down fast (Facing) Both modular – installed as half crossovers
No performance issues. Minimal maintenance Fewer issues than Thirsk Green Lane (Thirsk South, NR56V) Early POE failures due to teething troubles with new POE system Very quiet crossings, very small dip angles
Page 18 2019 pilot sites
Ulceby • C 13 crossover, D 10.75 turnout, E 15 turnout • HP rail and 350HT switch rails • Heavy freight route Farnborough • 3rd rail electrification • E 21 crossover, C 13 crossover (wide interval) Cogload • C 13 crossover
Page 19 2020 and 2021
Cricklewood (2020) • G 28 Transition crossover • Two levelled layout • First Hy-drive layout
Balham and Falcon Junction (2021) • First NR60 MK2 Double junction and 3 line crossover
Many other sites (over 30 point ends in total)
Page 20 NR60 Mk2 Evaluation
Providing technical leadership NR60 Mk2 – The right solution?
All of the layouts installed to date are reported to be performing well. Some layouts have been monitored very closely • Thirsk (High speed 125 mph – 4.5 years in service) • Ulceby (Heavy freight annual tonnage – almost 3 years in service)
Page 22 Geometry and Wheel rail interaction
Vertical and horizontal geometry has remained good for all layouts installed This is the latest trace from Broadholme installed 3 months ago. At Thirsk the S&C was almost invisible on the traces Wheel transfer is good on both the switch and crossings
Page 23 Switch operation
The IBCL Mk3 was developed to design out known failure modes The tubular supplementary drive provides a more positive drive that operates consistently in tension and compression
Switch operation has proved to be more reliable than equivalent (non NR60 Mk2) units nearby. Each first of type switch size has an integration test for each manufacturer. This is a check on operation, including headroom and an obstruction detection test. The longer switches are limited to Hy-drive. Testing shows that even the improved supplementary drive does not provide an acceptable level of headroom. NR60 Mk2 switches are designed to operate in non-ideal conditions
Page 24 Switch wear and damage
Concern over a repeat of NR60 Mk1 switch damage issues A smaller, but still high, peak load occurs on the steering switch. This occurs when the switch is much thicker than a NR60 MK1 switch, breakout is much less likely Ulceby is not a typical ‘trailing wear’ site, but has suffered wear and damage in the past. NR60 Mk2 has been combined with premium rail steels and lubrication
Page 25 Ulceby
Switch blade is R350HT rail, stock rail and switch extension is HP rail After almost 2 years the switches look unworn No actionable defects have developed. The trial and use of R350HT switches is being expanded, more rail is being procured The switches are weld repairable, if needed. A new flux cored welding process and competency has been developed
Page 26 Bearers and modular joints
Bearer joints with NG screws and green inserts NR60 stiffer track form Design and installation in line with NR/L2/TRK/3406
No issues reported on NR60 Mk2 sites. Thirsk and Ulceby have bearer joints and are being monitored closely (see indicators)
Page 27 Crossings
A combination of: • NR60 stiffer track support • Improved crossing design • Improved crossing profile • EDH (pre-hardening) in all cases
All NR60 Mk2 crossings are performing well. Each one is quiet, has a low dip angle.
Page 28 Challenges
Familiarity BRT files for C switches • Briefing Switch set up and stressing • Training Fastening system • Tooling Access for welders – alignment • Approach Material lead times
Treat the change as a project Share best practice NR/GN/TRK/065
Page 29 Challenges - Costs
What is the benchmark? NR60 will always cost more than NR56V – 56V has become the benchmark for cost NR60 Mk2 costs: • Unit rate (15-25% higher for materials) • Set up costs (patterns for crossings and plates) • Initial contingency costs
When comparing costs always make sure you compare like with like. The final cost is always higher than the base price cost estimate.
Page 30 Challenges - Costs
Mk2 costs – what will happen
• Unit rate (15-25% higher for materials) will go down as volumes increase and prices are agreed • Set up costs (patterns for crossings and plates) will only be needed for special or non standard layouts • Initial contingency costs will be eliminated as NR60 Mk2 becomes BAU for all
When comparing costs always make sure you compare like with like. The final cost is always higher than the base price cost estimate. • Spares • Extra panels • Delivery costs
Page 31 The benefits
Increased reliability Longer life of crossings, switches and the layout Reduced whole life costs Reducing initial costs
Page 32 Future developments
NR60 Mk2 H switch double junction with switch diamond Installation at Uddingston at Christmas 2021 New POE system on the switch diamond (VAE Unistar)
Page 33 Future developments
Further double junctions • A range of geometries have been defined • Units will be developed when required • Design, supplier and approval resources are critical
Higher Speed layouts • Turnouts and crossover • 100mph I switch • 125mph J switch • Development being funded by HS2 for use on connections
Page 34 NR60 Mk2 – A Team Effort
The NR60 MK2 range has been developed by the S&C Engineering Team with Matt Crompton as the Lead Engineer, but supported by the whole team S&C and component suppliers have been involved at all stages Universities and consultants have supported us in many area
Project teams have worked with us to make the pilot sites happen
Thank you to everyone
Page 35 Providing technical leadership