Eurostar woes

[Usenet Nutter]

Well you tell me the relevance to doing it yourself .

[newshound]

Because D-I-Y people are interested in getting to the root cause of a problem, so that they can fix it. And plenty of us are engineers in our spare time. And there could be lessons to be learned from this one at home or at work.

[sm_jamieson]

I see. Well they'll have to amend that one then. At least they had a recovery plan of some sort. But leaving the people in there so long is a public relations disaster, and I wonder if they will include the negated advertising spend in the total cost of the fiasco. Simon.

[John]

The media is so dumbed down that it wouldn't be able to write an explanation now. Ah - remember the sectioned drawings that used to accompany technical explanations years ago?

[Roger Mills]

Wouldn't that be preferable to a complete collapse of the service?

Or, maybe, they could stop the trains just short of the tunnel and remove the accummulated snow before entering the tunnel, if that would be quicker.

[mark]

Not all trains get stopped by snow:

[pete]

Not the best analogy considering frozen O rings and exploding shuttles.

While I don't have any sympathy with the way it's been handled, it does seem as if this sort of situation is very hard to foresee and even harder to test adequately. Just how many different types of snow do you account for? and how do you produce them to order on a country-sized rail network>

[pete]

On an exceptional basis, yes. However when your business proposition is to be as fast (or faster) than planes, time _is_ of the essence.

[Usenet Nutter]

Bloimey ..That's a bit tenuous that ...lol

[Dave Plowman (News)]

Given it's the first time this particular fault has happened, no. There would as likely be more faults due to changing locos often. Broken connectors, etc.

Or just redesign the shield for one which works with this type of snow.

[Dave Plowman (News)]

Of course. There's little point in having a high speed link if you have to stop twice just to change locos. As well as adding considerably to the costs.

[The Natural Philosopher]

Oh, its not hard to see.

Anyone who has e.g. taken a camera thats been outside in weather like this, inside, will have noted instant fogging as teh warm moist air condenses on to it.

They would have experienced MASSIVE consdensation on entering the tunnels, and they are high voltage beasts.. no doubt water is/was dripping from areas that were never expected to or designed to get wet.

Right. First think is , its not snow, it was rapid transition to warm moist air from very cold air.

Second thing, as to why not diesels? why indeed? As someone remarked on the beeb 'less managers and more engineers' would be a good start.

[Dave Liquorice]

Powder snow is hardly a new phenomina. It's bastard stuff and *will* get through the smallest of holes and be carried along in an air flow to a point where the flow rate drops to low to carry it. It'll then just build up and up at that point.

As an engineering problem on air cooled kit it's not an easy one to solve. You can't filter as the filters would clog, baffles would work but as EuroStar seem to have found very fine powder snow travels further than larger particle powder snow. Heating the air flow after the baffles might work, provided that the heat exchanger "holes" where big enough not to clog and there was enough heat to melt any snow in the flow and snow/ice build up on the exchange unit.

I'm sure there are facilties that could wind tunnel test a full size train power unit. Generating large quantities of fine powder snow might interesting but they seem to make snow for indoor ski slopes fairly easily, adapt that technology?

The basic premise that a following train can push a broken one out is a massive oversight or far too much optimisium in the reliabilty of the trains. The traction power supply is a single point of failure if nothing else. As a quick and easy solution the push out by following train is fine but it needs at least one preferably two, on standby, alternatives.

[Man at B&Q]

Normal has more than one value in this case so you can't neccessarily just use the nearest available loco.

MBQ

[Dave Liquorice]

But that would be true of a cold (but snow free) train entering the tunnels, not heard of that being a problem. The fine pwder snow is a important factor here. I suspect the power cars had lots of snow in them carried in by the cooling air. Rapid melting when blasted by 28C air resulted in flooded electronics...

Not sure I'd like to share a 30 odd mile long tunnel with a load of diesels...

Or managers that have the authority to manage or if they don't feel that they will be supported by the Company if they make a decision outside of their authority.

[TheOldFellow]

The answer may not lie in the design of the power cars per-se. They do have to be economic to buy and operate in normal conditions. I would have expected, however, a 'dry-out' procedure for the trains prior to entering the tunnel when powder snow had been detected. Something like:

1) Train diverted to dry-out layby, and stops. 2) Warm completely dry air blown through ducts for time X (until dry conditions in the important places) 3) Train resumes journey clearing the dry-out layby for next service.

Cost of fixed plant, infinitesimal compared with this fiasco, and with multiple other uses in normal service, including spot checks for terrorists. Delay is much to be preferred to disaster. "Ladies and Gentlemen, we regret that this service will be delayed by 15 minutes due to the extreme weather conditions which mean that we must dry the train before we enter the tunnel" is so much better than "sorry you had to sit in appalling conditions for 15 hours because we are incompetent at running a railway".

The Technical Director of EuroAsteroid needs to get his head out of his (expletive deleted).

R.

[John]

Some helicopter gas turbines use centrifuges to ensure sand doesn't enter the compressor

[Jules]

Hmm, it's like submarines, but without the water. They should be nuclear... :-)

[Jules]

... or make it worse ;)

[The Medway Handyman]

According to a spokesbod on local radio, it was condensation caused by unusually cold weather in France & comparitively warmer tunnels.

So I blame the French for not insulating France better.