Poor rail conditions?

[MichaelJP59]

My current commute is on the East Coast line to Leeds and today leaving Wakefield Westgate the (class 91) train was very slow, perhaps around 25mph for the first 70% of the trip to Leeds. The guard came on the PA and reported that the driver had told him that this was due to "poor rail conditions" and the train was going "as fast as he could make it go".

This seemed strange to me as even if poor traction meant low acceleration, speed would surely still build up to normal running speed, even if it took much longer than usual. Also looking over at the up line, there was no visible contamination of the rail and temperatures were mild (9 degrees) this morning.

Can anyone help?

Many thanks..

 

[jopsuk]

if he's having trouble accelerating, he may hold back on speed, as he'd have difficulty stopping too!

 

[najaB]

Also looking over at the up line, there was no visible contamination of the rail and temperatures were mild (9 degrees) this morning.

If it was due to leaf fall it wouldn't be easily visible from a moving train. That's why drivers get caught out.

 

[edwin_m]

Noticed the same thing at Grantham on Monday. An up 225 was moving off very slowly with the sanders spitting and the loco in a cloud of dust. This despite all the wheels of the train cleaning the rail before the loco went over it.

 

[Suraggu]

Class 91's are extremely light and with around 6000 bhp, the blowy conditions yesterday and overnight would have not helped rail adhesion. Put those two together and it does not make a good mix.

 

[AM9]

Noticed the same thing at Grantham on Monday. An up 225 was moving off very slowly with the sanders spitting and the loco in a cloud of dust. This despite all the wheels of the train cleaning the rail before the loco went over it.

Would the coaches clean the rail or just compact the leaves/mulch ready for the 91 to slip on?

 

[najaB]

Would the coaches clean the rail or just compact the leaves/mulch ready for the 91 to slip on?

The latter.

 

[MichaelJP59]

Class 91's are extremely light and with around 6000 bhp, the blowy conditions yesterday and overnight would have not helped rail adhesion. Put those two together and it does not make a good mix.

Interesting. On a related note on Class 91's (I'm a mechanical engineer rather than electrical) what creates the characteristic and rather loud noise from the driving locomotive, is it cooling systems?

 

[ac6000cw]

Interesting. On a related note on Class 91's (I'm a mechanical engineer rather than electrical) what creates the characteristic and rather loud noise from the driving locomotive, is it cooling systems?

Yes, it's mostly the traction motor blowers and electronics cooling (as with most electric locos).

Diesel locos also have traction motor blowers and radiator cooling fans but you tend not to notice that noise (as much) above the noise generated by the diesel engine itself.

 

[westcoaster]

My current commute is on the East Coast line to Leeds and today leaving Wakefield Westgate the (class 91) train was very slow, perhaps around 25mph for the first 70% of the trip to Leeds. The guard came on the PA and reported that the driver had told him that this was due to "poor rail conditions" and the train was going "as fast as he could make it go".

This seemed strange to me as even if poor traction meant low acceleration, speed would surely still build up to normal running speed, even if it took much longer than usual. Also looking over at the up line, there was no visible contamination of the rail and temperatures were mild (9 degrees) this morning.

Can anyone help?

Many thanks..

A couple of years back while on nights I left flitwick heading towards London, I just could not attain anything over 15mph, no matter how hard I tried sand no sand etc, in the end I just let it coast because you got to get stopped again ( plus I did not want to cause damage to the motors and wheels).

 

[Bigfoot]

You can only see the contamination when you are looking at the rail closely when stationary. As najaB said that's how drivers get caught out.

 

[Jamesb1974]

Poor rail conditions can catch you out as a driver in two ways.

Either whilst trying to accelerate or when trying to stop.

The other morning I had both. Firstly, when braking for adverse signals, the speedo dropped from 55mph to zero which is a surefire indication of locked wheels due to poor rail conditions. The only thing to do is take the brake off, and brake again, lighter and hope that it sticks (it did).

Then, later that morning whilst accelerating through 30 mph, the speedo suddenly whizzed around to it's maximum speed stop and the motors could be heard increasing speed dramatically. No indication of wheelslip or increase in amps though, even though the wheels were quite obviously slipping. Reduction in power, apply some sand and try again.

Different sections of line, but same weather conditions. You don't have to be able to see the railhead contamination to get caught out by it. Especially at this time of year.

 

[Fincra5]

By 442 was slipping all up the Brighton Mainline this morning.. leaving Wivelsfield took an age. Lovely smell of burning motors.

 

[HarleyDavidson]

By 442 was slipping all up the Brighton Mainline this morning.. leaving Wivelsfield took an age. Lovely smell of burning motors.

That's called not driving it properly. The driver should have been hand notching it, not cranking it.

Anything with a air/oil camshaft you can hand notch and do quite fine control of the power, I know that because I managed to restart a 13 car (yes a 13 car set, 5-WES & 8-CIG(G) which had got stuck) some years ago using hand notching.

Unfortunately hand notching is a dying art with modern traction systems.

 

[irish_rail]

That's called not driving it properly. The driver should have been hand notching it, not cranking it.

Anything with a air/oil camshaft you can hand notch and do quite fine control of the power, I know that because I managed to restart a 13 car (yes a 13 car set, 5-WES & 8-CIG(G) which had got stuck) some years ago using hand notching.

Unfortunately hand notching is a dying art with modern traction systems.

To be fair to the driver conditions have been very bad. I had a HST power car yesterday consistently slipping even in lowly notch two ...

 

[HarleyDavidson]

But HST's don't have camshafts do they? So driving something without one is a true art & you don't have sanders either.

A 442 has twin camshafts. One dealing with Shunt & Series (N1 & N2) the second dealing with Parallel & Weak Field (N3 & N4), you did have a Wheelspin light in the cab which told you when you were spinning, so you could ease the power back and avoid burning motors & damaging wheelsets & track.

 

[feliner]

Wakefield to Leeds line was awful yesterday for both braking and traction. I struggled from Outwood to Ardsley with a 322 at between 15 and 20 mph,and experienced wheelslide at most stations.

 

[Crossover]

I recall a service to Barrow last year (Class 185) which was slipping so badly it was sliding sideways on the rail!

I think the worst (in terms of just not getting anywhere) wheelslip I have witnessed was on the train from Brough last week - this one in fact:
http://www.realtimetrains.co.uk/train/G34251/2014/10/17/advanced

At South Milford, under the lowly light, there was a definite sheen on the opposite side tracks. We came to set off and I'm not sure the driver got into any notch - it took ages to reach even walking speed and even once we got to maybe 30mph, the sanders (we assumed from the noise) were still working overtime and we still weren't gaining traction!

 

[notadriver]

The WSP system will beat hand notching every time. Modern control systems allow the power to individual axles to be varied more quickly than is possible through hand notching an old camshaft type control system. This is because to lower the power setting power has to be completely shut off and reapplied on a camshaft controlled system.

 

[DarloRich]

Noticed the same thing at Grantham on Monday. An up 225 was moving off very slowly with the sanders spitting and the loco in a cloud of dust. This despite all the wheels of the train cleaning the rail before the loco went over it.

what? The wheels dont simply brush the leaves/contamination away - Would that it worked like that! I think there might also be a difference between the effect of the unpowered carriage wheels and the powered driving wheels of the locomotive!

Would the coaches clean the rail or just compact the leaves/mulch ready for the 91 to slip on?

have a guess. It aint the first one. The 91 then slips baking the leaves to the railhead making the next service have even more problems and so on till you scrape it all off and start again

 

[455driver]

I hear a 455 went pop at Surbiton today (Wednesday) with the traction motors giving up!

 

[O L Leigh]

The WSP system will beat hand notching every time. Modern control systems allow the power to individual axles to be varied quickly than is possible through hand notching an old camshaft type control system. This is because to lower the power setting power has to be completely shut off and reapplied on a camshaft controlled system.

Technically correct but operationally that's nonsense. Even with modern traction equipment WSP will not beat a deft hand on the throttle.

WSP intervenes when you've exceeded the limit of adhesion resulting in wheelspin by cutting the power. If you're spinning the wheels or if the WSP has cut the power you will not accelerate. The trick is to apply just enough power to the rail so that you don't exceed the limit of adhesion. If that means selecting a lower power notch so that you can gain momentum without the WSP interfering then that is what you do.

I've had a Cl317 refuse to exceed 65mph in notch 4 because it kept spinning up it's wheels even at that speed. I'd tried dropping sand but it didn't make enough difference to persuade the WSP to leave well alone. So I knocked it back into notch 3 and the unit ran up to 80mph without a sniff of complaint. On another occasion I was stopped at a signal between stations and as soon as I tried to get away the WSP intervened immediately. The only way out of that mess was creeping forward slowly using notch 1 and then carefully going up through the notches and dropping sand as the speed built. The same principle applies to the DMUs I drive now.

O L Leigh

 

[hassaanhc]

On Sunday, the 455 I was on was slipping, but only when the driver decided to give it loads of power http://youtu.be/qm5pk31j2lY

 

[455driver]

Thats just lazy driving!
Very poor and unprofessional.

 

[MichaelJP59]

Interesting first hand information To the layman it all sounds a bit like driving a car on packed snow, when you need to turn the traction control system off as it cuts in so early that no power can be applied through the driving wheels?

 

[edwin_m]

what? The wheels dont simply brush the leaves/contamination away - Would that it worked like that! I think there might also be a difference between the effect of the unpowered carriage wheels and the powered driving wheels of the locomotive!

Perhaps not the contamination but moisture on the rails is likely to be dissipated by previous wheelsets. At Grantham there were no trees in sight but it is possible that contamination had been carried into the area from somewhere round Peascliffe where it is a bit more leafy.

 

[HarleyDavidson]

The WSP system will beat hand notching every time. Modern control systems allow the power to individual axles to be varied more quickly than is possible through hand notching an old camshaft type control system. This is because to lower the power setting power has to be completely shut off and reapplied on a camshaft controlled system.

Nah, you're wrong with that. The more modern electronic traction systems are better as they can control the amount of wheel slip when applying power and the more modern WSP braking systems are quite good, they still can't beat the Mk1 brain and skill, braking earlier & lighter often yields far better results than the computerised WSP system can.

OK, you may be able to brake later with it, but you're increasing the chances of overshooting or sliding through or past a station or signal.

The driving of a train at this time of year takes skill & tenacity and you should use your basic skills to control it, as you never know if & when the system may let you down.

 

[notadriver]

I'm not saying WSP does everything and of course drivers should be accelerating in a lower power notch / braking earlier etc but i think it's a damn sight better than what a camshaft controlled DC train without WSP can achieve.

 

[HarleyDavidson]

No. O L Leigh has got it spot on with what he said & of course you have these things called Mk1 eyeballs & Mk1 ears too, so not only can I see & judge the distances accurately & check the railhead, check back to see what's occurring and I'm not worried about a bit of smoke coming off the rail, beacause I know that it's burning the contamination off. I let that happen for very limited time so not only not to overstress the traction motors but not to shift the tyres.

I can also stick my head out of the window & hear what the motors are doing. Camshafts are fine, provided that you use your skill & judgement with them and they far better than any electronic traction system in ice & snow, especially the modern one's which can't handle ice & snow and the electrical interference that it causes.

 

[matchmaker]

A couple of weeks ago the up Highland Chieftain lost traction at some point north of Aviemore (not sure where). It had to return to Inverness* to have another go, made it, but was cancelled at Edinburgh 120 minutes down.


*That's about 30 miles!