Train journey home.

[Dieselman]

Travelling home from Central London last night made me think of the journey as a whole.
Over 100 miles in 1hr, 20 minutes just wafting along was quite some achievement I thought, especially as we made a couple of stops on route.

It made me think of the power involved in getting the train to move along.
The train was an intercity 125 with two power-cars.

So if it can do 125mph with both engines running, how fast can it go with only one.?

 

[st4]

Question?

Two locomotives and one engine running or one locomotive only?

 

[Dieselman]

Complete train, but one broken down engine. In reality having the additional power car mass makes no difference to top speed.
Just for clarity a power-car is where the engine lives. There are two on an interecity 125, one at each end of the train.

 

[verytalldave]

The rolling resistance of steel wheels on a steel rail is VERY low. By far the greatest drag at those speeds is wind resistance. And Intercity trains are fairly aerodynamic. Providing the train is not fully laden, then I would say the second power unit is for backup purposes mainly. Just a guess.

 

[Dieselman]

RR of steel wheels on rails is 1,000 times less than pneumatic tyres on tarmac.

 

[verytalldave]

Is that an educated guess or fact?
Just seems a nice convenient round figure...............
Wouldn't have bothered asking if you had said 1034.5........

 

[st4]

Right, in other words the acceleration of the train may be slower, but it might just reach 125mph

The Intercity 125 is quite an old design, if you want really impressive diesel power try the Virgin Voyager trains.

 

[Dieselman]

Is that an educated guess or fact?
Just seems a nice convenient round figure...............
Wouldn't have bothered asking if you had said 1034.5........

It was a figure I read as a quoted figure some while ago. It may not be absolutely exact but is in the right order of magnatude.

 

[jaymanek]

havent you answered your own question... of course im sure it can reach 125 mph with just one engine, it will probably take a long time to get there though!

how do they ensure both engines are working at the same output?

 

[verytalldave]

Travelling home from Central London last night made me think of the journey as a whole.
Over 100 miles in 1hr, 20 minutes just wafting along was quite some achievement I thought, especially as we made a couple of stops on route.

It made me think of the power involved in getting the train to move along.
The train was an intercity 125 with two power-cars.

So if it can do 125mph with both engines running, how fast can it go with only one.?

BTW.............Do you know the answer?

 

[Dieselman]

havent you answered your own question...

I've been careful not to. Read carefully.

how do they ensure both engines are working at the same output?

They work as a pair. Them 'lectronics is damn good stuff. Trains are diesel/electric so there is no direct connection of the engine to the wheels.

I have also been informed the mpg is average 9mpg. Not bad for a train carrying 450 passengers.

Next question.
Am I sad for thinking of this..??

 

[Dieselman]

BTW.............Do you know the answer?

Yes.

 

[robert.saunders]

Is this defo a 125 or a 225?

 

[Dieselman]

Is this defo a 125 or a 225?

The example is a 125. It makes it easy..

 

[robert.saunders]

The example is a 125. It makes it easy..

Indeedy

 

[robert.saunders]

Does the 125 push & pull to achieve top speed

 

[scumbag]

nobody gives a stuff.

its public tranpsort and you should be shot, then hung and shot again for asking such a stupid question.

then you should be boiled alive for taking the damn train the first place.

And after that, you should be cut into peices for not using a Mercedes.


Now have this thread closed before someone else goes and does something daft like buying a train ticket. Hells' teeth, people may even consider the bus if the kind of thing carries on?


what is this world coming to?

 

[st4]

9mpg, I thought it would be sub 1pmg - I could get my old BMW to 8mpg. So my old car at times was less economical than a diesel train The 225 trains are solely electric and draw their power from overhead lines.

Does it work be electric drive then, whereby the diesel engine acts as a generator to power an electric motor? This would allow the diesel engine to run @ peak efficiency all the time, making the MPG higher.

How big is the fuel tank? It must be massive to be able to run upto Aberdeen to London without refuelling.

 

[Colin_b]

9mpg, I thought it would be sub 1pmg - I could get my old BMW to 8mpg. So my old car at times was less economical than a diesel train The 225 trains are solely electric and draw their power from overhead lines.

Does it work be electric drive then, whereby the diesel engine acts as a generator to power an electric motor? This would allow the diesel engine to run @ peak efficiency all the time, making the MPG higher.

How big is the fuel tank? It must be massive to be able to run upto Aberdeen to London without refuelling.

The electric drive acts as a transmission, so no need for clutches and gearboxes.

We have some class 66 locos at work - 3000 or so HP, and 6,000+ litre fuel tanks

When they are started from cold they produce an unbelieveable amount of smoke!

 

[verytalldave]

Judging by the sound they make when pulling out of Paddington for example, the diesel engine shaft is directly connected to the generator which sends variable power to individual electric motors.
But that is a total guess. I might be very wrong.