How does a train driver know when to start slowing down...

[TheBoyBilly]

Just my 2p-worth ( I'm a train Driver) All trains have a key of some sort. I have a Master Key (us Southern Region old boys call 'em EP keys) but train/loco-specific keys are becoming more common (you'd never inadvertantly go home with the key to a Class 66 loco..it's HUGE) You can't just get on a train and press a 'start' button.
As for braking, our route-knowledge gives us braking points for stations etc but they are a rough guide and you brake lighter and earlier if railhead conditions become poor. As for stopping patterns, these can be a nightmare. I nearly missed Preston Park once as my schedule book flipped a page by accident. The signaller 'looped' me into the far platform to allow a late-running Express pass me. It was only the conductor asking me why I hadn't released the doors that alerted me to the fact that I was looking at the wrong schedule. No harm done, but if I'd set off again without letting passengers on & off it would have been a 'disciplinary'. That was years ago....management don't allow much for human error.
And, daft as it may seem, you really need to know the layout in the dark. I have had trainees laugh at this until the reasons are pointed out to them. (for one thing, but by no means the main reason, it'll help you know exactly where you are in fog too when in the middle of nowhere, and where your next red signal is)
As for computers telling us where we are, that is true for trains such as Eurostar with In-cab signalling (no lineside signals to observe) but not for the vast amount of UK railways. Computers for the majority of trains control WSP & WSP (wheel-slip protection & wheel-slide protection, power to wheels and all manner of train functions, but not location information. There is GPS of course but that is mainly for onboard announcements, and for door-release control (not opening the rear 4 doors of a 12- car train at an 8-car platform for example, which is programmed in by the Driver at cab set-up)
SaltyDog will confirm this I'm sure, but computerising trains makes it much more difficult to fix a fault on a train nowadays but thankfully just re-booting the computer ( which is a pain for passengers because you lose carriage lighting etc) can get us out of bother. A lot of major faults now need a Fitter-and they can be miles away. And (getting a little bit political here) because of some shortsightedness, trains (especially in Southern region areas) come with very different couplings so that the chance of assistance is much, much reduced. If your sitting on a failed train, your stuck 'til maintenance staff appear. In the old days it was all 'buckeye' couplings. You could get round most problems and at least clear the line.

Bill

 

[BrumJim]

Northern don't have trains, they have buses with train bogeys on them :roll
(Not that I'm badmouthing their service, but a LOT of the rolling stock is over 5 years overdue for replacement)

Those trains don't have bogies. Just two wheelsets per carriage.
(sorry, pedant alert!)

 

[BrumJim]

Now that is something that has always puzzled me. Why are trains so solid and heavy - I mean, much heavier than buses? Collisions are extremely rare and in general the only things they run into are other trains, so I would have thought that if all the trains were equally light we would be just as safe and save huge quantities of fuel.

What is the engineering reason for it?

The history of trains is that if you are running steel wheels on steel rail, weight isn't too much of a problem, as long as you don't get steep grades (hills).
However the physics of it demands that trains remain relatively heavy because:
1) They need to be heavy to stay on the tracks. As they curve, the bogie has to rotate too. A high speed train has dampers that stop the bogie rotating too quickly (avoids hunting - yes, I know the last Labour government banned it, but doesn't help us here!), so the train needs to be above a certain weight to keep the bogie on the tracks.
2) The economics of a train means that you need to carry lots of passengers compared to a bus to be competitive (track access charges, stopping patterns, etc). Hence each carriage needs to carry more people than a bus, and hence has to be longer. This means that it also has to be heavier - a beam twice as long needs to be much more than twice as thick to take the same even load distribution. I'll work out how much thicker when I get my engineering brain in gear).
3) Trains also need to be strong enough to take the weight of all the people that can reasonably be expected to squeeze into a carriage and still operate safely. You cannot control how many people get on most trains. This only works with Eurostar and similar services.
4) Whilst collisions are rare, telling victims and their families this is of no comfort. Train strength is remarkable now - a train left the tracks at 96 mile/h (Grayrigg) almost 5 years ago, plunged down a bank, and with no additional safety equipment other than the train structure and interior design, only one person was killed. Try that in any other vehicle, and you won't see the same survival rate.

 

[BrumJim]

And (getting a little bit political here) because of some shortsightedness, trains (especially in Southern region areas) come with very different couplings so that the chance of assistance is much, much reduced. If your sitting on a failed train, your stuck 'til maintenance staff appear. In the old days it was all 'buckeye' couplings. You could get round most problems and at least clear the line.

Bill

Don't you have adaptor couplers on board for rescue purposes?

([controversial] they should change all the trains to Scharfenbergs anyway! [\controversial])

 

[BrumJim]

And if the bodywork was of an identical construction to that of buses?

I was addressing the question of why coaches were heavier than buses not why every rail accident is survivable.

All designs are a compromise else we'd be travelling in armoured trains travelling at walking pace with a man with a red flag walking ahead.

Sorry, feel like I'm monopolising here.

Trains are designed to take a head-on 60km/h collision and ensure that the body collapses in a safe and controlled manner, such that the deceleration is 5g or less (F1 driver braking from high speed for tight corner). This was taken as a compromise level, and sensible given the historic number of accidents at near this speed. However with new signalling (TPWS), such an accident is now very unlikely, and so debates rage as to what the criteria should be. This is difficult, as most recent fatal accidents are so chaotic as to make modelling and predictions almost impossible.
Also designed for various other scenarios, based on previous fatal accidents.

 

[TheBoyBilly]

BrumJim, I know what you mean about adaptor couplings, but they aren't kept in the emergency cupboard of our trains (442s) and, as far as I know Southerns's 377s or FCC's 319s or 377s. Only Southern's 455s have this kit as far as I'm aware (maybe 456s too), which is not much use south of Croydon on our patch. Our rescue loco (Class 73) has kit for this purpose but where that is at any given time is anyone's guess...it could be out trying to clear ice & snow off the third rail or even used for route learning purposes.. The railway has managed to wing it so far, but one day there is going to be a major problem and trains will be stuck all over the place. Progress eh? I am a Buckeye man myself, but I suppose it's a bit outdated for modern trains. I have reservations about Scharfenberg couplings, but I try to be open-minded. I supppose all passenger trains will have them in due course but that could be years away.

Bill

 

[Mad Doug Biker]

You can't just get on a train and press a 'start' button.

What I meant though is that once it is all set up with the keys, etc, certain diesel types have (or at least had) a start button so the engine could prime and eventually fire up, making a rather curious monotone noise in the process.
Certainly class 56s and '60s had them as did a few other classes such as HSTs.

I got (with permission) to start a class 60 (60064 I think it was) at Motherwell once many years ago, and press a button is exactly what I did. I have also heard quite a few other locos being started up, including 56004 once at Warrington, also many years ago now and beleive they were started in a similar manner.

Things will have changed, but I don't imagine they will have changed all that much.

And, daft as it may seem, you really need to know the layout in the dark. I have had trainees laugh at this until the reasons are pointed out to them. (for one thing, but by no means the main reason, it'll help you know exactly where you are in fog too when in the middle of nowhere, and where your next red signal is)

'Quality assured at 80mph in the dark'

 

[BrumJim]

Buckeyes are OK, until you need to add an electrical head, at which point you need a Tightlock. And much like The King of Beers, McDonalds Restaurant, and Probably the Best Lager, the Tightlock is anything but tight.

 

[TheBoyBilly]

I'm an old fuddy-duddy Jim. I want British Rail back!
MDB, that monotone sound you heard was oil pumps priming before allowing the engine to start. You're right of course, things haven't changed much. 66s are much-maligned (mainly by Drivers because of cab ergonomics) but I liked driving them in my freight days. Only ever had one serious fault (couldn't get over 5 mph, well actually the Driver who brought the train down from Liverpool couldn't) which was sorted by Crewe technicians talking me through a fault fixing procedure involving jumping in-and-out of both end cabs repeatedly, resetting the computer from both ends. I was knackered at the end, but got back to Southampton from Bescot lol

Bill

 

[TheBoyBilly]

I've been asked that question quite a few times, User13710

 

[Bigsharn]

Those trains don't have bogies. Just two wheelsets per carriage.
(sorry, pedant alert!)

Not Sprinters

 

[BrumJim]

Not Sprinters

No, Pacers. The ones that look like buses on tracks.

 

[marafi]

Well if i remember in Year 7 which is along time ago. The underground at the stations have the lights, and also the routes of the train drivers going should know when to stop. Speaking to control on the main line trains also helps.

 

[Soltydog]

No, Pacers. The ones that look like buses on tracks.

Make the most of them, cause they wont be around too much longer Can't meet Disabled People’s Protection Policy & they are all due to be withdrawn from service in the not too distant future

 

[Archie_tect]

[There should be level access into all train carriages from the platform... 'just' [easy to write but more complicated to do] need to raise the platform [in part or completely] since they can't lower the carriage body height- moronic that it has never been done. They even managed it on the Metro in Tyne and Wear.]