Freight Gauge Nuances Presented by Martin Osman 4 th November 2015
Introduction What s new in the field of freight gauging? Established or Benchmark suspension Standard Vehicle Gauge Data sheets (SVGD) New - W10a gauge Withdrawn W11 and W7-W9Plus lower gauges Considering cross-winds (T1031) 2
Established or Benchmark suspension What do we mean when we say Established Suspension Or Benchmark Suspension? 3
Established or Benchmark suspension GE/RT8073 Issue 3 sets out the definition: Established suspension A suspension which has traditionally been used for vehicles conforming to a particular standard vehicle gauge, and whose characteristics have been used by the infrastructure manager to demonstrate that a route is clear for the particular standard vehicle gauge. Suspension types for use with W6a: 3 piece. Y series. LTF (low track force). TF (track friendly). Swing motion. AM3 (axle motion). BR long link. Friction pedestal. UIC double link suspension. 4
Established or Benchmark suspension GE/RT8073 Issue 3 sets out the definition: Benchmark suspension A suspension for which 8073SVGD is available. It can be used to demonstrate compliance with a standard gauge or clearance to infrastructure with greater accuracy than established suspensions. Suspension types for use with W6a: 3 Piece. Y25. Y33. Y33c. Swing motion. LTF13 5
Established or Benchmark suspension Why have we made the distinction between the two? To provide clearer criteria for new suspension / bogie designs To continue to provide for existing wagons (Grandfather rights) and hopefully reduce costs of gauging analysis To move away from wagon specific gauging compatibility To help to provide for new designs of more track friendly bogies 6
Established or Benchmark suspension How do we add a suspension / bogie type to the Benchmark list? Carry out a dynamic analysis as described in RIS-2773-RST Validated vehicle model Recognised Multi-Body Simulation software package Complete a Vehicle Gauging Data (VGD) workbook Range of vehicle speeds over a range of installed cants Tare and Laden loading condition Curving analysis (to determine wheelset position) Compare movement data to existing Benchmark suspensions Movements shall be within the existing envelope for all cases A Research proposal has been put together to develop the methodology (issues concerning vehicle mass, C of G height and model validation) 7
Established or Benchmark suspension Example of current Benchmark vehicle movements 8
Established or Benchmark suspension What if the new suspension movements exceed the current Benchmarks? If the body bounces 10 mm too high reduce the body height by 10 mm If the body sways 15 mm too much at the top corner reduce the top corner width by 15 mm What about Containers? We cant width reduce Containers! Consider fixing arrangements? There is always a logical solution! 9
Standard Vehicle Gauge Data sheets (SVGD) The Standard Vehicle Gauge Data (8073SVGD) should be used to calculate the dynamic movements and the resultant swept envelope, to support gauging studies The Data for many established suspensions for freight W gauges is available on the RSSB website 10
Standard Vehicle Gauge Data sheets (SVGD) What are the benefits of using the SVGD worksheets? Simplicity If you are using an Established or Benchmark suspension then you simply have to check that the vehicle fits within the static gauge Reduced costs The dynamic movements have already been determined so further dynamic modelling is not required If you are not using an Established or Benchmark suspension a methodology for demonstrating compliance is provided. David Johnson is discussing RIS-2773-RST in the next presentation 11
New - W10a Gauge What is the purpose of the W10a gauge? W10a gauge is a load gauge carried on lower gauge compliant wagons. It was developed to define the maximum size of a load that may be carried on wagons with a deck height of between 820 mm and 995 mm with a maximum bogie spacing (or axle spacing) of 14.020 m and a bogie wheelbase of between 1.8 m and 2.2 m. W10a gauge was developed to accommodate 9' 6" x 2500 mm container traffic on a wider range of bogie types. The gauge is simply a square box with the following co-ordinates: Point X (mm) Y (mm) 1 1262.5 820 2 1262.5 3891 12
New - W10a Gauge What is the difference between W10 and W10a? The difference is the suspension / bogie types that can be used. The W10 gauge is specifically for use with: Y25 Y33 The W10a gauge can be used with all Benchmark suspensions. W10a Static Gauge The gauges are almost the same but the dynamic swept envelopes differ! 13
Withdrawn - W11 and W7 - W9Plus lower gauges Why have the gauges been withdrawn? The W11 gauge No routes had been cleared to it Industry consultation agreed no use for it The W7 W9Plus lower gauges The new Lower Sector Vehicle Gauge (LSVG) has replaced them Industry consultation agreed to reduce the No. of lower gauges The Industry is encouraged to use the LSVG! 14
Considering cross-winds We have a long standing requirement to assess the effects of cross-wind, but how do we carry out the assessment? GE/RT8073 Issue 3 now sets out the requirement for assessing the effects of cross-wind for W10, W10a and the W12 gauges: For the W10, W10a and W12 gauge, if the vehicle does not use an established or benchmark suspension, it is permissible to declare the vehicle to be compliant with the upper dynamic gauge if it can be demonstrated that, in all conditions of speed, cant and side wind loading, its swept envelope remains within that of a vehicle or vehicles with a benchmark suspension conforming to the required standard vehicle gauge. Following the conclusion of research project T1031, GE/GN8573 now provides a detailed methodology for carrying out the cross-wind assessment. 15
Considering cross-winds Methodology: The swept envelope is calculated using a multibody simulation (MBS) dynamic model for the wagon travelling at a range of speeds up to maximum speed over a range of installed track cants. The swept envelope calculations are repeated for a range of 10 minute mean cross-wind speeds. 16
Considering cross-winds Specific Wagon body aerodynamic coefficients are supplied b C Fy C Fz C Mx 0 0.000 0.000 0.000 10 0.172 0.033 0.104 20 0.392 0.175 0.242 30 0.789 0.261 0.487 40 1.140 0.279 0.696 50 1.223 0.224 0.740 60 1.187 0.177 0.725 70 1.220 0.185 0.751 80 1.236 0.142 0.765 90 1.225 0.109 0.758 The calculation details are provided in GM/RT2173 and are the same as used for calculating pantograph sway 17
Considering cross-winds We need to avoid this But that is going beyond gauging! 18
Future??? 19
Thank you