Briefing Note. Use of standard gauges for non-passenger rail vehicles. March 2013

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1 Briefing Note The Use of Standard Gauges for New Non-Passenger Rail Vehicles March Purpose This briefing note is written to guide the manufacturers and introducers of non-passenger rail vehicles onto the GB rail network in respect of gauge clearance for; New designs of locomotives New designs of wagons, on track machines, and other vehicles built to W6A gauge Modifications to locomotives, wagons, on track machines or other vehicles, which affect their static or kinematic gauge profile Network Rail wishes to alert introducers of new or modified vehicles of the need for early discussion with us to ensure that their vehicle is compatible with the infrastructure. This note is written without prejudice to contractual rights, Railway Group Standards and published clearances or approved exceptional load permissions. This document and associated documents are available on the Network Rail website 1. Guidance for passenger rail vehicles can be found here. 2. Scope Please note that this document covers gauging aspects of vehicle design and introduction only. All other elements of infrastructure compatibility will need to be addressed separately prior to operation on Network Rail infrastructure (e.g. electromagnetic [EMC] compatibility, route availability etc) as outlined in Group Standard GE/RT8270. The operational clearances for existing vehicles are as published in the Sectional Appendix Route Clearance Tables. Network Rail is contractually committed to provide operators of existing vehicles with the clearances shown in these tables. 3. Background W6A and locomotive gauge are standard gauges for non-passenger carrying vehicles. Most of the network provides adequate clearances to these gauges. They have existed for many years, W6A (issued in September 1990) being an amendment to the much earlier W6 to take account of the third rail profile. Locomotive gauge has a similarly long history. However, it is only in the last few years that improved technology has been available to measure the infrastructure and analyse clearances to W6A and Locomotive gauge with complete accuracy across the network. This improved measurement has shown that there are many structures on the network that are foul to W6A and / or Locomotive gauge - many more than were envisaged when the standard gauges were created. Some structures are foul in the upper sector (more than 1100mm above rail level) but most of the foul clearances are caused by structures in the lower sector (such as platforms and underbridge girders). Historically, engineers and operators throughout the industry have assumed that clearance to the Standard Gauges should be available throughout the network. It is understandable that Standard Gauges can be perceived to reflect a comprehensively available gauge. Unfortunately, whilst this would be desirable, the reality is not and has never been this simple although this realisation has only emerged in the last few years. Building a new or modified design of vehicle to W6A (or other Standard W Gauge) does not ensure network wide gauge clearance. Page 1 of 10

2 Network Rail is in the process of improving clearances to many of the relevant upper sector arches and overbridges and that programme is continuing. However, improving clearance to lower sector structures is more problematic. To provide an example of the issues involved please see figure 1 below. The underbridge girders to both the left and right of the track are foul to W6A though they do not impact materially on the operation of existing vehicles. To improve the clearance to full W6A cannot be achieved without complete reconstruction of the bridge concerned a very expensive option that would provide compliance on paper but would deliver little or no tangible benefit for the industry. As a result it does not make sense to address the foul to W6A until the bridge is due for renewal when it becomes life expired - which could be in many decades time. There are no restrictions to freight traffic over the bridge illustrated. This is because the design of most freight wagons reduces their width to less than the theoretical maximum for W6A along the length of the wagon so that they can negotiate curves. All standard freight bogie designs are well within W6A. The design of non-freight vehicles - particularly on track machines is more complex. A design which takes full advantage of W6A in a location of low lateral throw (e.g. adjacent to the bogie) may be restricted over this bridge and similar structures. Figure 1 In summary, parts of the infrastructure are not compatible to the standard gauges (Locomotive and W6A). The standard gauges are not go anywhere gauges despite the historical assumption that they provide this facility. Standard gauges are, in reality, go most places gauges - but there are exception structures that are foul to these. It follows that, vehicles built to these standard gauges are not guaranteed network wide operation. In response to industry needs, Network Rail has published the routes that meet W6A gauge fully in the Sectional Appendix (available through our website 2 ). Many are shown as Y*, indicating a problem in the lower sector. A summary of British Gauging Practice 3 has also been published by the relevant industry standards group (known as V/S SIC Vehicle and Structures Interface Committee). This is on the RSSB website and is recommended for further background information. Page 2 of 10

3 4. Guidance Suppliers may continue to design vehicles to the standard gauges but need be aware of those parts of the vehicle that are most likely to infringe the exception structures and are advised to design the vehicle to take account of the practical issues that apply to those areas. They need to check an accurate dynamic model of the vehicle against the exception structures to maximise network compatibility. These checks should be undertaken when the vehicle is still at the design stage. This document provides the guidance on how to do this. To ensure that their vehicles are introduced in a timely manner and to reduce the possibility of gauging problems arising, the introducer is advised to: Make early contact with NR when contemplating introduction of new non-passenger vehicles (i.e. all classes of on track machines, freight vehicles, rolling stock and locomotives). This needs to be early in the design stage (see below for contact details). Be aware of this briefing note on standard gauges and the extent of non-compliant structures (a list is available from Network Rail on request). Decide whether full network clearance is desirable or operational restrictions are acceptable Agree a gauging strategy and clearance methodology with NR at the start of the project, (see GE/RT8270 p25) for which the options are: 1. Apply absolute gauging methodology. This is highly recommended as the chosen solution as it eliminates all doubts as to the dynamic size of vehicles and their gauging compatibility with the infrastructure, removing all uncertainties from the process. Please note that this method requires a ClearRoute compatible vehicle model to be created, for container wagons this model also needs to individually show all combinations of freight container which can be carried. 2. Build to standard vehicle gauges (i.e. loco gauge, W6A etc). This allows vehicles to run over the routes that are clear to the standard gauge but will cause operational restrictions (usually prohibitions) to apply over the routes that are not clear to the standard gauge. All current applicable restrictions to the standard gauge will be inherited by the new vehicle. 3. Apply comparative gauging (i.e. demonstrate that the vehicle is same size or smaller than an existing vehicle). This will limit operational routes to those cleared for the comparator vehicle and may lead to substantial operating restrictions. Candidate and comparator vehicle models should be developed with comparable methodologies and both vehicles should comply with GM/RT2149. A comparator vehicle has to pass the test of operating in significant and regular traffic which may not be the case for some existing vehicles. 4. Apply hybrid gauging (i.e. a mix of comparative gauging and absolute gauging for parts of a vehicle which sit outside the gauge of the comparator vehicle) Combinations of the above methodologies may be permissible to achieve route clearance. Operating restrictions as a result of using standard and comparative gauging methodologies can seriously impact the ability to operate the vehicle over the chosen routes, including some busy trunk routes which are important for freight. Whilst these options may appear to be quicker and cheaper than absolute gauging, they have on occasions led to delay, added cost and uncertainty bringing vehicles into revenue earning operation. They have also led to delays and added cost at later stages within the operational life of the vehicle when additional route clearances (e.g. for new container or swap body sizes) have been requested. You should discuss your choice of options carefully with Network Rail to ensure that the outcome is in your overall best interests. Page 3 of 10

4 5. Issues to consider The issues which relevant parties need to address can be summarised in the following: Manufacturers/introducers: Need to decide the extent of the network over which the vehicle is intended to operate. If network-wide operation is not a requirement this can reduce the number of exception structures that constrain the design and may make build size options and clearance methodology simpler. Need to prove compatibility with infrastructure and other rolling stock applicable to the routes of intended operation. To do this NR recommend the use of absolute gauging via approved analysis software e.g. ClearRoute, using the National Gauging Database (NGD), this will require a dynamic vehicle model to be created. Network Rail: Needs to provide up to date infrastructure survey data for the entire network, which is done via the National Gauging Database (NGD). Needs to provide a list of routes cleared to standard gauges (shown within the Sectional Appendices). Network Rail will also provide lists of exception structures to W6A and Locomotive Gauge on request. This will reduce the costs of absolute gauging as it involves analysis of only c structures out of c. 160,000 across the whole network. Needs to sign off the NRAP summary of compatibility once the introducer has provided all evidence to demonstrate compatibility with infrastructure. Needs to thereafter maintain clearances granted to vehicles on the routes for which they are cleared and published in the Sectional Appendix (available through the NESA website 2 ). Operators: Need to operate the vehicle in accordance with compatibility criteria. Page 4 of 10

5 6. Gauging process flowchart Page 5 of 10

6 Key to process flowchart; 1. Propose routes of operation and gauging methodology - Manufacturer/end users to decide routes where vehicle is to operate and agree gauging methodology with Network Rail i.e. absolute gauging/standard gauge etc 2. Are required routes cleared to standard gauges? - Review intended routes of operation to see whether they are cleared (available from Sectional Appendices) 3. Are route restrictions acceptable or practical? - Standard gauge compliant routes may have restrictions i.e. bay platforms etc, review to see whether any potential restrictions are a barrier to operation. 4. Where the routes required are cleared to the standard gauge, design vehicle to the standard (W6A or Locomotive) gauge profile - Vehicle to be either compliant with W6A or Locomotive gauge profile or: 5. Where the routes required are not cleared to the standard gauge, design vehicle to modified W6A or Locomotive gauge profile Vehicle to be compliant with the modified profile (see next section for details) 6. Populate vehicle model template spreadsheet - All relevant information to allow the vehicle model to be created to be entered onto the spreadsheet, this allows easy creation of vehicle model profiles. Guidance to the completion of the spreadsheet can be found in the RSSB research report The V/S SIC guide to Vehicle Gauging Data Format Create the vehicle model Supply template spreadsheet to relevant consultant to enable creation of a vehicle model which can be used within ClearRoute to analyse clearances. Note this is desirable even when the vehicle is standard gauge compliant as it will make future cascades to routes not clear to the standard gauge easy to analyse. 8. Analyse vehicle model against known exception structures only A list of exception structures to either Locomotive or W6A gauges is available from Network Rail on request. By only analysing against those structures the analysis time and subsequent costs are minimised 9. Are clearances/restrictions acceptable/practical? The analysis may result in a list of structures with less than normal clearances to the vehicle. The project team and Network Rail will need to discuss whether the reduced clearances and/or restrictions to the operation are acceptable and/or operationally practical e.g. if there is a restriction in one bay platform it may not represent much of an operational issue. 10. Amend infrastructure or vehicle? - The project team and Network Rail need to decide on the most effective way to gain gauge clearance for the vehicle, this can be by the application of either of the following: 11. Amend vehicle design if the vehicle model is found to be foul to a large number of difficult to modify structures it may be more cost effective to amend the vehicle design. 12. Amend infrastructure if the vehicle model is found to be foul to only a few structures it may be more cost effective to amend those structures. 13. Demonstrate gauge compatibility once clearances are acceptable, the vehicle has to be proven to have compatibility between both itself and the infrastructure and itself and other vehicles on the routes where it is intended to operate. This relates to not just gauging but to a number of other disciplines including but not limited to electrical compatibility, route availability, signalling compatibility etc. 14. Build vehicle and bring into service begin using the vehicles on the infrastructure once all certification and commercial issues are resolved. Page 6 of 10

7 7. Modified W6A or Locomotive Gauge diagram Figure 2 indicates the three areas where the exception structures encroach into the standard gauges. These are: at the top where flat deck bridges are too low at cant rail level due to low arch bridges at or below sole bar level (this is where the majority of exception structures encroach on the gauges) As a guide, Network Rail advises that designing within (i.e. to less than) 50 mm of the standard gauge in these three locations, should eliminate most exception structure problems. N.B. This is not the same as the width reduction required by the Gauge. In practice, this tends to happen as a normal function of the design process since most vehicles are width reduced in accordance with a Standard. For example, sole bars are subject to this normal width reduction function and their width is consistent for the full length of the vehicle. These have never been known to cause an issue. The parts of a vehicle that are vulnerable to clashing with the exception structures are ancillary fittings such as footsteps, sanding boxes, hand brake wheels, yaw and vertical dampers (with their brackets) and speedometer attachments. These are generally located at locations with little or no lateral throw near the bogie and are not subject to normal width reduction. Some items that are width reduced may also be problems: e.g. fuel tanks. Other items known to be problematic are buffers (especially on vehicles with large end throws) and exhaust manifolds. Whether a vehicle design is actually compatible to the infrastructure or not varies from type to type. An identical component that passes without problems on one vehicle type may cause a problem on another design due to a slightly revised longitudinal position on the vehicle or different bogie centres. Therefore, the only way to check with certainty is to model each vehicle dynamic type accurately. Page 7 of 10

8 4500 Typical Worst Case Bridge Typical Worst Case Arch Standard Gauge (Dynamic where appropriate) W6A or Locomotive Suggested Lower Sector Line Typical worst Lower Sector exception structures Lower Sector Structure Gauge (GC/RT5212 App A) Rail Figure 2 Page 8 of 10

9 8. Container Wagons The gauging of flat deck wagons designed to carry containers incurs added gauging complexity due to the need to achieve compliance of the combination of wagon and containers conveyed with the enhanced freight gauges of W7 through to W12. For the wagon itself, introducers need to follow the process outlined above to design the wagon to meet W6A. In addition there are further gauge related issues that have to be considered so that the wagon can be used in traffic without problems. The wagon design needs to state the maximum dimensions of containers (height, length and width) that the wagon can carry within each of the standard container gauges W7 through to W12. Network Rail will then arrange for this information to be inserted in the Working Manual for Rail Staff Table J (GO/RT3056) The wagon design and the container nominated in the bullet point above need to comply with the definition of the W gauges W7 W12 contained in GE/RT8073. These definitions have been derived from particular existing wagons and new wagons and their loads will have to fit within the assumptions derived from these existing wagons to conform to the gauge. For instance, the dynamic movement of the bogies used in a new wagon will need to match the most dynamic of the existing wagons. For bogies that are the same as an existing wagon used in the definition of the gauge, these checks become a simple static comparison; for new bogie designs, considerable work is needed to check that the dynamic movement of wagon and load sit within the dynamic profile of the gauge. Likewise, the gauges make assumptions on the use of UIC spigots or twistlocks; these assumptions effectively mean that wagons fitted with UIC spigots are restricted in their deck height. For instance, only twistlock fastenings can be used with W11 gauge. A dynamic ClearRoute compatible vehicle model of the vehicle is required to assess containers for special clearance for a particular wagon / container combination to be permitted to exceed the headline published W gauge. This model needs to individually show all combinations of freight container which can be carried by the wagon. In practice, freight operators take advantage of space above the headline published W of a route. Enhanced W routes are cleared by Network Rail to accept the standard gauge plus 100 mm of normal clearance (see GE/RT5212). This 100mm is used by Network Rail over the lifetime of the track for renewal of ballast and to maintain the track. Network Rail receives about 6 to 8 requests a week from freight operators to use this space on a special basis which may be granted if it is available. A typical request asks whether a particular wagon with a container say, 50mm taller than the maximum height allowed on that wagon for the W gauge, can travel. To answer this, Network Rail assesses a model of the wagon, complete with a model of the container requested over the route concerned, using ClearRoute. If a dynamic vehicle model is not available then these requests cannot be accommodated. This reduces the utility of the wagon to freight operators. 9. Future actions Network Rail is working with V/S SIC to seek agreed changes to; Revised Locomotive standard gauge, Create a new universal gauge for the lower sector which is compatible with the gauge that new infrastructure has to meet. The proposals for this gauge are currently being analysed (see RSSB Research project T977). Work is progressing with these proposals, under the control of the V/S SIC, however, to implement them involves considerable amount of technical research and industry consultation on the change to Group Standards, both of which take some time. Page 9 of 10

10 Where the network is renewed, clearance to published gauges for the route shall be achieved. At a number of locations we are undertaking accelerated improvement to the infrastructure loading gauge as a result of our commitments to the industry. These routes are part of the most intensively used Strategic Freight Network and their enhancement provides accelerated assurance of compliance with Standard Gauges. 10. Any further questions Please contact the following: Gauging issues; Mark Ward, Gauging Manager, Network Rail mark.ward@networkrail.co.uk General freight queries; Ian Cleland, Freight Development Manager ian.cleland@networkrail.co.uk Footnotes 1 This document can be found on the Network Rail Web Site; the link is from a page entitled Standard Gauges at 2 NESA is a (free of charge) subscription data source available to any interested stakeholder details are on the Network Rail web site at 3 The V/S SIC guide to British Gauging Practice is RSSB research project T926 and can be found on the RSSB web site at 4 The V/S SIC guide to Vehicle Gauging Data Format which provides guidance to the completion of the vehicle model spreadsheet can be found on the RSSB web site when it is published in Page 10 of 10