INFORMED SOURCES e-Preview May 2011
Well, I certainly earned my holiday in the south of
It’s a fascinating story and I hope you enjoy reading it as much as I enjoyed researching and writing about this timeless design.
ETCS – grappling with interoperability.
Research tames anti-social bogies.
IEP – credible-alternative costs the next battleground?
It may seem that I have been writing about the European Train Control System (ETCS) for ever and a day. It sometimes feels like it.
With the Cambrian Lines Early Deployment Scheme (
First of all, there is the question of what do you mean by ETCS? Here we need get into Versions of the ETCS System Requirements Specification (SRS).
Cambrian
Network Rail’s implementation proposals are currently based on V2.3.0d, which still has some missing features. These omissions are due to be closed by a new Version 3.0.0, otherwise known in the trade as ‘Baseline 3’. But compliant systems won’t be commercially available for another three or four years.
Incompatible
So that’s why Network Rail is going ahead with V 2.3.0d. But even that is not easy because the ‘European’ in ETCS is a fib. Instead of an interoperable pan-European system, each country implementing ETCS took a bespoke approach. So we should really write (D)TCS, (CH)TCS (I)TCS and so on
And it gets worse. None of the European suppliers are currently offering fully compliant ETCS. So on-board equipment from one supplier may not talk to another’s Radio Block Centre.
Network Rail’s solution to this signalling
Implementation
ETCS implementation is due to start with the Great Western Main Line in 2014. The programme is complicated by the partial electrification, the residual operation of IC125 and the presence of the original British Rail ATP.
This results in an equally convoluted resignalling programme. First, the GWML will be re-signalled with conventional multiple aspect signals, retaining BRATP. Then, after a pause of around 18 months, the new signalling will be overlaid with Level 2 ETCS.
Both signalling systems will then operate in parallel until the lineside colour light signals are removed around 2025-26. Meanwhile, some IC125s will need to be retrofitted with ETCS for Continued Service Operation.
The East Coast Main Line between
HNIF began life as the test track for the Thameslink central core signalling. This is due to have the same ‘conventional resignalling then ETCS overlay’ treatment as the GWML.
Thameslink’s new ETCS equipped train fleet will be compatible with the Southern sections of the ECML and MML. South of the
So the 2007 National Implementation Plan is obsolete. In a recent Parliamentary answer DfT said that the NIP would be updated to ‘fully reflect the lessons learnt from the Cambrian deployment’. But when it will be published is another matter.
Harsh bogies tamed
Having been fiercely critical of two attempts at producing rail research strategies, I thought it was about time I wrote something positive about Research & Development. And earlier this year a classic example of R&D saving serious money came my way.
After the Hatfield derailment brought down Railtrack, Network Rail’s engineers have become masters of the 5 pence sized contact patch between wheel and rail. Understanding the effect of vehicle dynamics on rail wear and Rolling Contact Fatigue (RCF), one thing. Practical application of that understanding is another.
RCF and rail wear is primarily determined by the energy in the wheel/rail contact patch. And this energy is, in turn, linked to the primary yaw stiffness of the bogie.
Network Rail modelling predicted that the suspension characteristics of the Desiro EMU bogie would increase rail wear compared with the Mk 1 stock being replaced. And so it turned out. RCF defects on the
As a result Network Rail initiated a project to eliminate the cause of the wear and track damage by reducing the stiffness of the Desiro suspension. The key was the rubber bush in the swinging arm primary suspension.
These bushes need to be very stiff to prevent the bogie hunting at high speed. But on curves, the bush should ideally be soft. The stiffness of the rubber bushes is thus a compromise, favouring high speed stability.
Network Rail’s solution to this conflicting requirement is the HALL bush made by Freudenberg. Where a conventional bush is a solid rubber tube, the HALL bush contains two hollow chambers connected by a small diameter pipe. The chambers are filled with hydraulic fluid.
At speed, when the longitudinal forces on the bush are at high frequencies, the pipe restricts fluid flowing between the chambers. This makes the bush very stiff for good stability. Conversely, when curving, the forces are applied at lower frequencies, allowing time for the fluid to flow between the chambers so that the bush becomes relatively soft.
Tests showed that at maximum speed the HALL bush was around 15% stiffer than the existing solid rubber bush. But at low speed it had only 20% of the stiffness of the existing equipment. These characteristics have reduced the energy in the contact patch by a factor of 6-7 according to Network Rail.
Retrofitting of HALL bushes to both SWT’s Class 450 and Class 444 Desiro fleets is due to start in July under a two year programme. Costing £4 million, the modification programme is expected to pay for itself by the end of the SWT franchise in 2017.
IEP cost claims challenged
With the Intercity Express Programme firming up, Members of Parliament have facts to question and Ministers are having to answer with cold numbers.
For example, replying to a written question from Andrew Gwynne MP, Transport Minister Theresa Villiers claimed that the bi-mode IEP is estimated to save ‘around £200 million (net present value)’ compared with the alternative of a fleet of ‘all-electric trains’ with diesel locomotive haulage beyond the electrified network.
Now this seemed improbable. Could a fleet of 125 mile/h EMUs, plus a small number of diesel locomotives to haul them beyond the wires, really be more expensive than five car IEP bi-modes each with the thick end of £750,000 million of Cummins finest diesel engines underneath the floor?
Andrew Gwynne thought it unlikely and asked for the source data on which the NPV calculation was made. According to the answer, ‘The capital rental of full length electric trains was assumed to cost around £260,000 per month, with the capital rental of each locomotive assumed to cost around £30,000 per month’.
And these numbers seemed even more improbable. While Theresa did not specify what she meant by ‘full length trains’, a full length IEP was 10 cars, although the standard formation is now five cars
So let’s assume we are talking 10 car trains. That means rentals of £26,000 per vehicle per month. Since money costs around £9,000 per £million per month that puts the capital cost at £2.9 million per vehicle.
Even the current Pendolino lengthening order cost ‘only’ £2.65 million a vehicle – for a 140 mile/h high- performance tilting train. Informed Sources reckon a standard EMU should be around 32 million, max.
Doing the same sum for the diesel loco gives a capital cost of £3.3 million each. Informed Sources suggest £2.5 million each is more representative
DIY
So there was nothing for it but to fire up an Excel spreadsheet and do the job properly. A complicating factor was capacity, since IEP has, notionally, 26 m long vehicles and a standard EMU would be 23m.
So I have compared the annual capital and maintenance costs, plus variable track access charges, for both five and six car EMUs against the proposed IEP fleet. With five cars the credible alternative is significantly cheaper. With six cars there is not much in it. Even so, I can’t see how the IEP Bi-mode solution would have a £200 million better NPV.
Coupling.
Last month’s e-Preview brought the biggest reader response ever. And one thing that exercised you particularly was the statement by the Transport Secretary, that connecting a diesel locomotive to an electric Intercity express passenger train would take nine minutes.
‘Rubbish’, you all said. Lord Bradshaw asked where this ridiculous number came from and was told that ‘DfT consulted with Network Rail, train operating companies and other rail industry stakeholders on train coupling time assumptions’. Apparently, the nine minutes was at ‘the upper end of the range of responses’.
However, the appraisal modelled a seven-minute dwell ‘for any manoeuvre involving coupling at one end and uncoupling from the other’, and a shorter dwell for simpler coupling manoeuvres. It also allowed for the ‘reduced approach speed into stations where coupling is to take place’.
And, no, I can’t make sense of it either.
On to Swansea
Meanwhile, don’t write off Cardiff-Swansea electrification just yet. Our Prime Minister does tend to say what the audience want to hear, but on a visit to
Now here’s an interesting thought. According to Informed Sources, the 70 bi-modes in the 1 March announcement is the very minimum viable quantity. Wire to
No expensive bi-modes, fewer diesel locos. What price that dubious NPV?
Roger’s Blog.
I’m writing this the day after returning from our holiday in Nice which was a triumph of public transport and high speed rail. Going, we caught the 07.22 Eurostar to
Since our last visit Nice has gained the first line of its light rail system. You can tell that I was in holiday mode because I failed totally to spot that there weren’t any overhead wires in Place Massena. The Alstom Citadis trams drive through on battery power, leaving the open space uncluttered by masts and electric string. Instead of which you have masts carrying illuminated statues – part of the artwork linked to the new system.
What with Easter and royal weddings, there’s a shortage of working days ahead. But this week I am meeting
On the way back from the meeting I’m stopping off at St Pancras for a coffee with a chum who is writing a history of the Brush Class 89, one of my favourite locos – probably because it was the nearest thing to an electric Deltic!
Currently May is fairly quiet. This should give me the chance to catch up on outstanding offers of visits to factories. But events have a way of filling up the diary and foiling such self indulgence. We shall see.
Roger