OT: Steering a train?

[The Natural Philosopher]

Indeed. Locking the wheels probably simply damages them in time. So attempts are made to prevent that.

The acceleration and decelaration of trains is pretty appalling.. 0-60 in one minute is quoted.. :-) Once off te rails who knows what brings the train to a halt..bouncing off the sleepers would be one way..digging into the gravel another..

I also question the wisdom of having points anyway in an isolated place..

I also note that as agaisnt the trains of my youth, where railway cranes would be routinely deployed down the lines to clear wreckage, they seem to be faced with building and access road to get land borne cranes in situ.

Why?

[Huge]

You must have owned some pretty crap cars, then, since every one I've owned in recent years can.

I expect you're not pressijg hard enough. Few people do, hence Mercedes' EBA.

[David Hansen]

On Mon, 26 Feb 2007 10:54:48 +0000 someone who may be The Natural Philosopher wrote this:-

Not when one considers the weight of a train and the smoothness of a steel wheel on a steel rail. This smoothness is the reason trains need little energy to move, but it also means that stopping is slower.

Emergency crossovers are provided at regular intervals to make single line working and rescuing of failed trains easier. Without them more time would be expended recovering from such problems.

Ask Mr Hidden, whose report into the train crash at Clapham Junction filled the police with the confidence to start investigating things about which they know little or nothing.

[Bob Martin]

Really ? Traffic came to a stop on both lanes of a motorway near Salzburg (I was in the inside lane) and a big Merc went past me in the outside lane with all 4 wheels locked but still doing well over 80 mph. Could hardly see him for smoke, but he did manage not to hit anything.

[Dave Liquorice]

Most cars won't *let* you lock the wheels these days. Anyone else noticed the much decreased number of skid marks on roads these days compared to

10 years ago. Any car that I've had that didn't have ABS could lock the wheels at any speed, doing at high speed wasn't good for bowel control though!

[Ian Stirling]

Or a horse yard... I hate people that don't put in units. At least define it the first time it's used per program.

[Bob Eager]

Well, that would be slightly populist, but also open to criticism as an outdated unit!

[Tim Downie]

Not just Mecedes. It's trickling down to more mainstream cars now.

I discovered mine has it (in the heat of the moment so to speak) the other day. (A WV Touran). I have to say, I was quite impressed.

Tim

[Brian Sharrock]

Knowing nothing about the incident; other than what I can glean from photo's in the media; it seems to me that the carriages and locomotive are lying off an embankment on the 'wrong side' from a 'Down Line'. I can't judge whether or not the 'Down Line' is workable nor am I able to judge from photo's whether a 'railway crane' -as you've described it - would be capable of reaching over the damaged track and lifting substantial weights aloft from three/four storeys below? I presume, perhaps naively, that the railway and lifting engineers 'know what they're doing"! Do you?

[manatbandq]

They don't have concrete sleepers in them. Different situation entirely.

MBQ

[ARWadsworth]

So there are less skid marks in peoples pants as well!

Adam

[ARWadsworth]

The first generation of ABS did have faults. I live on a steep hill and arrived home when there was snow on the road. I came slowly down the street and the ABS kicked in and would not allow me to stop and reverse into my parking spot. I passed my house at 5mph and had to drive around the block before trying again with the ABS fuse pulled out. The snow built up in front of the locked wheels and allowed me to stop. I do believe that ABS no longer works below 10mph to prevent this effect and I am also sure I have read that gravel and snow with an ABS braking increases stopping distances not shortens them.

Adam

[Roger Mills]

Yes, you're right - stopping distance on soft snow *is* reckoned to be shorter with the wheels locked - and maybe on other soft 'ploughable' surfaces too.

To return to the original topic, maybe Mr Branson's driver's act of heroism was the pull the ABS fuse on the train once he'd realised that he was going on a detour?

[Autolycus]

I've explained the mechanism of a derailment turning into a pile-up in another post in this thread, which must have set some sort of record for false information and ill-informed speculation.

Derailment investigation was my job for over ten years.

[nightjar]

First, ABS allows you to both steer and brake. Second, locked wheels wear flats on the tyres.

Colin Bignell

[nightjar]

They used a Police pursuit car with modern tyres and ABS alternately enabled and disabled. If you do the Austrian emergency services' winter driving course, you can see the video.

Colin Bignell

[Dave Fawthrop]

|!>> The Metropolitan Police did a series of experiments that showed that |!>> the difference between the stopping distance of a locked wheel and a |!>> rolling one is minimal. |!>

|!> So why have car makers spent loads of dosh on developing systems that |!> prevent wheels locking and why are such systems pretty much standard fit |!> on all new cars? |! |!First, ABS allows you to both steer and brake. Second, locked wheels wear |!flats on the tyres.

Only used mine in anger once! hit some intermittent black ice and the sensation scared me not a little. Wondered what on earth was happening. But confirm that I could both steer and brake at the same time.

[Dave]

So, basically, you are saying that ABS is a total waste of money. I can't believe that.

Dave

[Dave]

As they are on major roads and motorways. You can spot them by there being a bolt on extra to the barriers in the middle of the road.

Dave

[nightjar]

No, you missed the bit about being able to steer as well. Few people can brake in a bend on black ice without the benefit of ABS and sometimes you need a combination of braking and steering to avoid a collision.

Colin Bignell