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‘Victorian infrastructure limitations preclude trains longer than 250 metres’

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In March 2011, the editorial director of Railnews, Alan Marshall, wrote to his local newspaper complaining about what he saw as the inaccuracies of the ‘Stop HS2’ campaign. In the interests of accuracy, he wanted to “draw attention to some factors”.

'A response to Joe Rukin's letter' by Alan Marshall, Kenilworth Weekly News, 24 March 2011

‘A response to Joe Rukin’s letter’ by Alan Marshall, Kenilworth Weekly News, 24 March 2011

Mr Marshall went on to “draw attention to” the “factor” that the Stop HS2 campaign’s “preferred alternative, known as Rail Package 2 (RP2), just does not stack up in providing sufficient extra capacity on the southern section of the West Coast Main Line… Victorian infrastructure limitations of the West Coast Main Line preclude trains longer than 250 metres”.

But did the Stop HS2 campaign actually have a “preferred alternative”? And do ‘Victorian infrastructure limitations on the West Coast Main Line preclude trains longer than 250 metres’?

Alstom Transport: Each 11-car Pendolino train on the West Coast Main Line is 265 metres long

Alstom Transport: ‘Each 11-car Pendolino train on the West Coast Main Line is 265 metres long’

Coventry station from above (Google maps)

Alan Marshall: “The Victorian infrastructure limitations of the WCML preclude trains longer than 250 metres — notably at Coventry”

Contrary to the claim made by Mr Marshall, trains longer than 250 metres operate every day on the West Coast Main Line. A need to extend WCML intercity platforms is unlikely to arise in the next 15 years, but if it did, it would certainly be possible at Coventry (and many other locations). In terms of scale, disruption, and cost, the civils of platform extension — and junction grade separation — are nothing like those involved in building 560 km of HS2.

Unfortunately, certain sections of the railway press — such as Rail Magazine and Railnews — cannot be relied upon to provide accurate information about HS2.

[Engineer sets out plan for more trains on HS2, Railnews, 16 Mar 2012]

[…][HS2 Ltd’s Prof Andrew McNaughton] said HS2’s control system would be based on ERTMS Level 2 train control, and would be designed to allow headways of two minutes, giving a theoretical capacity of 30 trains an hour. At the moment, a maximum of 18 is envisaged.

Headways would be maintained by trains stopping intermediately, such as at Birmingham Interchange, and then departing on ‘acceleration lines’ up to 14km long, so they were running at high speed before being slotted back in behind a fast train that had just overtaken them.

Railnews story, 'Engineer sets out plan for more trains on HS2', Railnews, 16 March 2012

Railnews story, ‘Engineer sets out plan for more trains on HS2’, Railnews, 16 March 2012

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Written by beleben

October 15, 2015 at 10:53 am

Posted in High speed rail, HS2

Tagged with , ,

2 Responses

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  1. As a regular user of the 16 coach 4 trains (356m plus loco) per day services on the West Coast (and East Coast on occasion) main lines I do wonder at what you find special about the 11-coach Pendolinos, which are in turn shorter than some of the trains that used to use these routes. Special excursions still, as far as I’m aware trail 13 Mk 1’s (260m) and of course you may remember that the White Rose services had trains of 312.36 metres in length running between Kings Cross and Leeds/York, with only a gauge clearance issue preventing their use North of York where they would easily fit into Edinburgh Waverley where twice daily a train of 396m plus loco’s on each end is re-marshalled on the through platforms – themselves able to take 2 x 250m trains when operated as 2 contiguous platforms.

    Speaking of the White Rose it provided an apposite echo of the £140m white elephant which was an earlier image/hype-driven ‘high speed rail’ project for which we still have the great sheds at Polmadie and Longsight, although both no longer shouting that they were the destination depots for Eurostar – someone must surely have a picture of the ‘ici’ banner at Longsight? I nearly also got a picture of the Eurostar-Night stock one evening when our coach stopped at Warwick services, en route to storage presumably and now still running in Canada?

    At a recent rail stakeholder meeting the MD – who had seen the full cycle going round since British Rail went to sector driven businesses and then privatised TOC’s noted in the latest split and reforming the it seemed to happen roughly every 10 years – perhaps we can reflect on the Regional and Night Eurostar as cheaper and less damaging but still a model of where HS2 might just be charging towards on a far grander scale.

    Dave H (@BCCletts)

    October 15, 2015 at 1:46 pm

  2. Prof McNaughton’s claim in 2012 that the acceleration tracks would be 14 km long to enable the trains to accelerate to the same speed as trains on the main line appears to differ from the approach he used in a paper he wrote for HS2 Ltd in August 2011 “Signalling headways and maximum operational capacity on High Speed Two”. It appears that the highest speed points (turnouts) available for connecting the acceleration tracks to the through track are limited to a maximum merge/diverge speed of 230 kph so there is little point in having longer acceleration or deceleration tracks that would allow for higher speeds. HS2 have confirmed that the acceleration tracks will be 2 km long and that HS2’s “reference train” will take 1 minute 30 seconds to reach the points at 165kph from standstill in Birmingham Interchange. Once on the mainline it will lose time to a preceding train until it reaches the same speed. In his 2011 paper, Prof McNaughton claims this will take 25.5 km and 324 seconds and it will lose 69 seconds to the first train. However, he completely fails to consider that a following through train, travelling at full speed, will also gain 69 secs on the merging train so it will need to have this additional margin in its headway from the first train. Prof McNaughton also considered a merging speed of 225kph and claimed that the merging train would lose 46 seconds to the first train but again he did not consider the following train. He came to the conclusion that at a merging speed of 165 kph the worst case capacity would be 21 trains/hr but this would increase to 22 trains/hr with 225 kph turnouts.

    HS2 have provided me with costs for different speed turnouts. The cost of a 130 kph turnout is £250,000. A 170 kph turnout costs about three times as much and one for 230 kph costs around £1.5 million. Clearly in 2012 Prof McNaughton was not unduly bothered about the cost of 230kph points or 14k acceleration tracks. Presumably higher speed points will also have a shorter life and/or need more expensive maintenance.

    As southbound trains at Birmingham Interchange will have started off from many different origins, and some will have travelled on the classic network, it seems highly unlikely that all the through trains will be spaced ideally to create the maximum gap for an accelerating train. In such circumstances the departure time window will be reduced, perhaps to the extent that it becomes too small to ensure that the accelerating train can fit into its slot. As Birmingham Interchange will be catering for airline passengers, many with bags, it may also be difficult to ensure that a train is ready to depart before its critical time window disappears.

    It is always worth remembering that merging will be much easier at lower speeds and capacity will increase. The 2009 Traction Energy Modelling report produced by Imperial College for HS2 Ltd showed that increasing the maximum running speed from 300kph to 360kph between London and Birmingham only saved 3.5 minutes but used 23% more energy. Despite the ever increasing costs of the scheme, and changes to the way its benefits should be evaluated, it appears that HS2 and DfT have not seen fit to even think about looking at whether the initial brief, largely set by Lord Adonis, makes any sense.

    johnma

    October 16, 2015 at 11:40 pm


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