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Has reversion to ETCS Level 2 sorted Railtrack's signalling problems on the WCML? Er, no, it's made them worse – much, much worse
At one stage in the Gallic Wars, Julius Caesar had three things to do at one and the same time. Compared with those responsible for signalling on the West Coast Main Line, Caesar had a cushy number.
Consider what has to be done between now and, variously 2 June 2002 and 29 May 2005 .
First and foremost Railtrack is committed to installing the Train Protection & Warning System (TPWS) at all signals protecting conflicting movements by the end of December 2002, although the legal end date is 31 December 2003 .
That includes 900 signals on the WCML. Now implementing TPWS is not a trivial operation. It means installing the two sets of speed detecting loops on the track and then wiring them into the lineside signalling equipment case.
As the Clapham accident showed, you have to be very careful when altering signal wiring. And the Hidden report into the accident resulted in stringent qualification requirements for signalling tests and procedures that have made installing signalling equipment a very slow process compared with other railways (see Iberian Interlude).
So TPWS is going to occupy a significant proportion of that limited pool of qualified signalling equipment installers – a pool that has shrunk as the signalling companies have reduced staff to match Railtrack's cut back in new signalling investment. And Westinghouse have been barred from TPWS installation for some reason.
Next, on the same track, Railtrack has to install the track mounted balises to support whatever type of speed control emerges for Virgin's tilting trains. The West Coast is pretty curvy and at many curves there may have to be three balises, one to say, speed restriction ahead, another to check the speed at the entry to the curve and one after the curve to display the new line speed. Balises will also have to be installed at locations where restricted clearances mean that tilt has to be temporarily switched off.
These balises, which will be the standard units developed for the European Train Control System, will have to be installed and tested in time for Virgin to start running its Pendolini at 125 mile/h from 2 June 2002. Fortunately, they don't have to be connected to the signalling system, but someone has to programme them (argument still ranging over bright balise vs smart train) and have possessions to install them and test them
Meanwhile, the decision to revert to ETCS Level 2, in place of the all singing/all dancing radio moving block, has pretty well guaranteed that Virgin will not get 140mile/h operation in May 2005. Not that the original radio based moving block signalling would have been ready before 2007-2009 (now Alstom tells us).
But given that the simpler system will involve much lower technical risk, how can it make things worse, you may well be asking? Here's how.
Let's recap why radio based moving block signalling was flavour of the month for so long. First, radio meant you could get rid of all that expensive lineside kit and its maintenance, not to mention renewal. Second, moving block gives you more capacity.
In vain did my vastly experienced signalling chums point out the flaws in these articles of faith. They were old railway dinosaurs: Professor Brian Mellit, Railtrack's then Director of Engineering & Production had seen the future and its blocks would move, first on the Jubilee Line and then on the WCML.
Moving block's ability to deliver extra capacity was always suspect. With all the trains on the fast lines running at the same speed, moving block gave no benefit, while on the slow lines reconciling the variations in traction and braking performance was a huge technical challenge.
But it was left to Dutch railway engineers to demolish the moving block argument. Their recent studies have showed that when you allowed for the delay between the driver applying the brakes and the pneumatic brakes coming on, the capacity gain was destroyed.
Even more devastatingly they pointed out that to maximise capacity with moving block you also had to assume that the train in front would brake normally, with the following train stopping in the same distance. But as the Eschede accident in Germany , and Ladbroke Grove most recently, showed, trains can stop suddenly when they hit each other or a lineside obstruction.
So bye-bye moving block, hello ETCS Level 2. Now you might thinks that moving down in the complexity hierarchy would save money. In this case you would be wrong.
In ETCS Level 3, you can get rid of lineside signalling because the train knows where it is from balises on the track. All the vital safety kit is in the Radio Block Centre (RBC) instead of being spread over hundreds of miles.
So each train calls up the RBC on its digital radio and tells the vital safety computer where it is and how fast it is travelling. The RBC thus knows where every train is and what it is doing.
As yet undefined vital safety systems calculate what is needed to maintain safe separation and the RBC radios each train individually every few seconds with its maximum speed and Limit of Movement Authority, ie how far ahead that maximum speed applies, This information is displayed in the cab.
But ETCS Level 2 keeps the existing trackside train detection equipment (track circuits or axle counters) and interlockings and the cab display simply replaces the lineside signals .
Instead of driving multiple aspect signals, each interlocking sends this information to the RBC: don't ask me how, probably by fibre-optic landline. Somehow the RBC knows which train is where – (don't ask, probably from the train describer), cross references this location with the signalling data, and transmits the equivalent of signal aspects to the cab display in each train by radio. And for 140mile/h you need to look five or six signal blocks ahead – the equivalent of a flashing green aspect.
So instead of retiring the existing 1960s vintage signalling, Railtrack now has to replace the conventional signalling on the WCML south of Crewe if Chris Green is to have the cab signalling he needs to run at 140mile/h in 2005. Not to mention Railtrack keeping its commitment to have Automatic Train Protection on its InterCity lines.
But, in addition to this unplanned and unbudgeted resignalling, Railtrack still has to build the as yet pretty nebulous RBC and get GSM-R radio working and link the conventional lineside kit to the RBC.
Now this column never says ‘I told you so'. What never? Well, hardly ever. This is not because of any innate modesty – perish the thought. No, it's just that whenever I refer back to past issues for a reference and find some example of stunning prescience in a column, I turn the pages to see what else I got right and invariably find some example of toe curling naivete, over optimism or just plain ignorance, that I resolve not to provoke readers to do the same.
But, just this once I will refer you back to the January 1999 Informed Sources where I published Railtrack's published breakdown of the £2.2billion cost of the West Coast Route Modernisation. And I wrote: ‘ At which point note that resignalling and control is budgeted at £485million. But Railtrack say TCS will cost between £500million and £1billion. That doesn't leave much for a couple of Network Management Centres and extensive resignalling of junction areas with solid state interlocking.
Is the WCML doomed to be forever tarted up on the cheap?'
There you are, right and wrong. Because the cost of signalling and control for the WCML, including conventional resignalling for ETCS Level 2 , is now £1.9 million. And it seems to me that if the improbability of that £485million was obvious to a failed traction engineer a year ago, it seems odd that no one at Railtrack spotted the discrepancy.
When it comes to the choice of conventional technology for this resignalling, likely to cost around £750million the five year deadline for PUG2 means there is no choice. It has to be that British world beating technology, the Solid State Interlocking.
No, this isn't blind nationalism. While Railtrack is encouraging two European manufacturers to bring their technology to the UK , neither has got safety case approval. One pilot scheme (Siemens) is stalled and the other (Ansaldo) uses a new electronic interlocking which saw its first application in Rome recently and reportedly fell over on the first day – which happens in the best regulated of signalling technology.
Now, normally, new technology is piloted somewhere quite, SSI cut its teeth at Leamington Spa. But under its programme to bring in new technology and resources Railtrack allocated Ansaldo's new interlocking to the Manchester South resignalling scheme.
This gives rise to yet another cause for concern. Manchester South resignalling is crucial to all those using the station where more capacity is needed by 2002 – that date again. But the proposed computer based interlocking still has to go through the Railtrack Safety Review Panel. Given the rate of progress on simple, proven, low cost interlockings, like those from Vaughan Harmon and Westinghouse, where the suppliers now have long and bitter experience of Railtrack's safety approvals process, I can't see the new mainline interlocking for Manchester South being ready by June 2002.
Brief interlude to illustrate the scale of the approvals problem. On the Norwich-Cromer resignalling, which uses a Harmon dual processor vital safety interlocking, humming away safely in large numbers in the US of A, the number of safety case documents prepared by or for consultants got so large that an uberconsultant had to be appointed to co-ordinate all the consultants' work.
So, Railtrack has better brush up its hand signalling for when the first Virgin Pendolino crawls into Manchester .
Now only Alstom Signal and Westinghouse Signals can supply SSI hardware. They can also do scheme design, as can WS Atkins, and have installation and commissioning teams.
Adtranz Signal, which has the signalling scheme design and implementation facilities in the UK has told Railtrack that it is not prepared to supply SSI packages which it would have to source from the other two majors. Instead it is negotiating a contract to trial its EBILOCK electronic interlocking at Horsham.
Time for another diverting interlude. One of the reasons for bringing in foreign signalling firms was to increase the design and installation resources available. Wrong again. The two low cost schemes are soaking up Brit BoS. Even more risible, CSEE, which is fronting up the Manchester South project for its parent Ansaldo, decided that UK signalling principles were so different that it only a UK firm could do the scheme design and Westinghouse obliged.
Given the five year time frame, plus the unprecedented penalties Railtrack faces if it fails to deliver PUG 2 to Virgin in June 2005, the boot in signalling procurement is on the other foot. After years of browbeating the signalling companies for being too expensive, inefficient, incompetent and slow when commissioning, Railtrack is now dependent on Alstom and Westinghouse to dig it out of a huge hole – or at least limit the damage.
Will industry be magnanimous? Will they hell. This is the private sector and firms are not going to take on silly timescales at silly prices. Remember that if the signalling is late, the contractors will be blamed.
Assuming that Railtrack can get the tender documents out yesterday, strike a deal quickly, and organise a whole set of new possessions, you might have south of Crewe resignalled with SSI during 2004. The logical approach would be to roll Westinghouse's current Euston-Willesden resignalling up through Watford to Rugby and, in parallel, have Alstom resignalling from Rugby and up the Trent Valley .
Back when hard nosed signal engineers were in charge of Railtrack's West Coast resignalling, the consensus was that about four signals would have to be moved to give sighting or braking distances 125mile/h running in 2002. Remember that the Virgin Pendolino will have a shorter braking distance than IC125 since it brakes at 9% adhesion all the way down from 125, whereas IC 125 is limited to 7% between 125 and 100 mile/h.
Then the rats got in and the latest news is that 400 signals will have to be moved. Yes four hundred.
Yes, I know it's unreal. Yes I know it means more possessions and more work for an overstretched signalling resource. No I don't know why grown up people do this sort of thing.
Railway Group Standard GM/RT2042 call for a train to stop (worst Braking performance) from 225km/h in 1775metres. When Virgin tested Eurostar on the WCML in 1997, the stopping distance was 1750m.
As the WCML's existing signals average out over the whole line at around 1000/1100 yards (installed in pre-metric days), the distance between the double yellow and the red is considerably longer than 1775 metres. Weird eh?
But, glimmer of hope, I hear that the need for changing signal spacings is being reviewed. If the new answer is more than 10, Tony Fletcher should throw the report into the waste paper basket and drag some grizzled signalling engineers out of retirement and tell them to kick ass.