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INFORMED SOURCES September 2005

HST2 – long, lean, fast but frugal

Getting HST2 right is going to need a lot of thought

Here is Transport Secretary Alistair Darling addressing the Railway forum annual conference on 21 June. ‘The Department will be responsible for taking on the key strategic challenges that face the rail industry… for example, the replacement of the High Speed Train fleet.

These trains have served passengers effectively for almost thirty years and have been one of the great success stories of the British railway.  I am determined that their successor should meet the same high standards.

To do so, we will need to learn the lessons of he past.  For instance, we need greater standardisation - one type of train across the network.

We need to get it right - to properly scope and test the new design, so that it can be introduced smoothly and without causing any drop in reliability.  And we need to ensure that we consider how all aspects of the system work together - not buy a train without any consideration of how it operates on the track, or of what passengers actually want.

But most importantly of all, we need clear accountability and strategic leadership.  This project will be led by the Department as a key part of setting the long term strategy for the rail industry. And we will work closely with the industry – not only the Train Operating Companies, although they have an important role, but also Network Rail, the RPC, manufacturers and safety bodies.

We will attach enormous importance to delivering a successor to the HST.  We will be demanding rapid progress in taking this work forward, with the first step being the development of the specification and invitation to tender, which we expect to issue in the first half of next year'.

Engineering first

Phew! Even a political Houdini of Mr Darling's expertise will find it hard to weasel out of that commitment if things go pear shaped. And, in my book, the key lesson of HST, which must read across to its successor, is that it was engineering led.

At the time, the Advanced Passenger Train (APT) was seen as the future. But my old English Electric chum Walter Jowett, having moved to British Rail, and former GNER apprentice Terry Miller had other ideas.

Well-formed and focused ideas two. Thanks to the parallel development of the strategy and the technology it needed to happen, just 22 months after construction was authorised, the High Speed Diesel Train demonstrator rolled out.

Some 35 years on we are not anywhere near like so well organized when it comes to replacing what became IC125. DfT Rail doesn't even have a Chief Engineer – and when it finds one (still waiting for the call Dr Mitchell) the job title will be Director Technical & Professional, which doesn't install confidence.

To get things moving Clive Burrows, Engineering Director, First Rail Division has been seconded to DfT Rail as a Senior Technical Advisor for six months starting in October. Clive probably has more IC125 experience than anyone in the railway and must make sure that the civil servants acknowledge this real world expertise.

Longer

His appointment confirms that the engineers are starting to regain control of HST2. My many chums in the various Systems interface committees, including Clive, must be dead chuffed by Mr Darling's remarks about not buying a train without any consideration of how it operates on the track. And as reported last month, the Vehicle/Track Systems Interface Committee (V/T-SIC) reckons that when the new InterCity gauge is available by Christmas, it will accept a 26m long vehicle slightly wider than the existing Mk3.

This is not an innovation, but a case of rediscovery following the dark ages. At the start of the 1990s InterCity was looking at a conventional replacement for the aborted APT. And in April 1991, the late (and much lamented) Andrew Higton and the very much with us Ron Temple gave a paper to the IMechE Railway Division on the Mk 4 and Mk 5 coaches.

‘Mark 5', you may ask? Yes, this was the basis of InterCity 250, a 26m long vehicle which, claimed the authors ‘is now feasible for InterCity routes with minimal infrastructure expenditure' . Tenders had been invited on 11 March for up to 45 250km/h (140mile/h) trains for the West Coast Main Line based on the Mk 5 coach.

Drag and weight

As you recall from the item on MadLev (Informed Sources April 2005 ), it is aerodynamic drag that dominates power demand as speed rises. So for 140mile/h, the Mk5 was to seek aerodynamic efficiency through a smooth exterior, minimum gaps between vehicles and a minimum cross sectional area.

For HST2, I suspect 200km/h will be adequate and passengers would prefer extra width and height to minimum drag. But note that the cross sectional area of GNER's Mk 4s is 2.85% smaller than a Mk 3. InterCity calculated that, at 1984 energy costs, the net present value of the reduced drag was just over £1 million in modern money. And that, dear reader, was one justification for IC225 being narrower than IC125.

Even then it was recognised that the Mk 4 was a heavy lump. Or as Andrew and Ron tactfully put it ‘the Mk 4 was considerably heavier than the Mk 3'. As a result, the target was for the 13% longer Mk 5 to weigh the same as the Mk 4.

Table 1

Effect of energy cost for IC250 train of variations in weight and drag. £'000s per train year in mid 1990 energy costs in 2005-06 money

Table 1 comes from their paper and shows the saving or extra cost of energy from changes in vehicle weight and drag. I have brought the figures into current money, but electricity prices have fallen since 1990 so use this as a quick and dirty comparator.

As you can see, cutting 20% off both weight and drag saved around £60,000 per train per year.. That may not sound a lot when subsidy to the railway is £5billion a year, but with a 45 strong fleet and a 30 year life you start to get serious money. And energy costs are rising.

Andrew and Ron also calculated that over a 30 year life and an 8% discount rate, the net present value of a tonne saved was about £2,400 in today's money.

More lightness

Now these aspects of drag and weight may seem like angel choreography, but it is tiny details which add up to an energy efficient vehicle. As the aircraft design maxim goes ‘simplicate and add more lightness', which is pretty much what Terry Miller and his team did with IC125.

So, if we base HST2 on a modern version of InterCity's 15 year old vision, we get the following comparison. And as you can see we get back to the weight per seat of the Mk 3.

Table 2

Passenger coach weights

But is that good enough? Well, not compared with Japanese railway engineers.

This chart, courtesy Prof Rod Smith at Imperial College and redrawn for Rail Business Intelligence, compares complete trains rather than coaches. If HST2 is to match IC125, it will have to be 25% lighter than Pendolino: the latest Shinkansen is half the weight per seat.

And there is more to this than energy. Additional mass translates into higher track forces, equals more maintenance which is paid for through higher variable track access charges. So somewhere in the specification should be a maximum figure for variable TAC.

This is likely to challenge the European Big three who seem bent on complicating and adding more heaviness. Of course, the poor dears will bleat about crashworthiness and so on, but even that figleaf may vanish.

Economic and safety regulation are being combined in the UK under the Office of Rail Regulation. This provides the specifiers of HST2 the opportunity to challenge such nonsenses such as the half metre crush zone at each of a coach.

Perversely, Hitachi , who fancy a go at HST2, have got carried away with the British obsession with crashworthiness. Their Channel Tunnel Rail Link Domestic electric multiple units promise more megajoules energy absorption than anyone else in Europe . As result, the trains will weigh around 750kg/seat.

Improvement

Four areas seem to offer scope for improvement in HST2, starting with toilets and air conditioning where European manufacturers have chased the cheapest offers around the world. Whenever a contractor got to grips with the technology, someone somewhere else would offer to do it cheaper. If you travel in a Desiro on Great Eastern, a handy tip is to take a crowbar with you in case the sliding door for the disabled toilet jump off its runners.

Next is wiring. We've been promised multiplexing over fibre optics, instead of miles, and tonnes,of copper wire, for nearly two decades. Aircraft can do it with pulses of light, why can't the railways?

Finally there are bogies. Bombardier actually use the BR Research Conceived B5000 bogie (conceived as the Advanced Suburban Bogie for Chris Green 's Network Rail in the 1980s). Lord knows what a Class 22X would weigh and cost to run with a couple of Eurolump track crunching bogies underneath. It could be their secret weapon in the HST2 bidding.

Hard act

So making HST2 Mr Darling's ‘worthy successor' to the original could well be another mission impossible for my old chum Richard Horton, late of Virgin and now DfT Rail's Head of Procurement.

It won't help that DfT Rail's yet to be appointed Technical Manager Rolling Stock is expected to have a track record in rail vehicle design and specification or maintenance of only five years. Compared with the giants who created IC125 he, or she, will be wet behind the ears. Can first spare Clive for more than six months?

All the Eurogiants will try to sell homogenised standard Eurotrains. If procurement is sub-contracted to a ROSCO it will try to play ultra-safe. The consultancies lack experience and vision.

What a strange situation where after 35 years of technical progress, HST2 could well be less suited to the needs of the capacity-hungry, energy frugal railway of the 21 st Century than the original.

Continues.........