Pendolinos pantograph

[Pumbaa]

Realised the other day whilst doing some spotting that all the Pendos passing by had their rear pantograph raised.

From NW Rail noticeboard, I suspect this is not far from the truth.

Some interesting news about the Class 390 Pendolinos related to the use of the current-collecting pantographs when on the electrified lines where they normally roam. Each train set has two of these, one on the third carriage from the 'front' and one on the third carriage from the 'rear.' Only one is required for normal working, and the original intention was that the rear one (in the direction of travel) should be used, and in their early days around 2004 this was the case. However, soon after entering passenger service, it was decided that the front one was to be used. An apocryphal story at the time was that Richard Branson thought this looked better ... although a more prosaic, if cryptic, explanation is 'infrastructure issues.'

However, these issues have now been resolved, we are told, and a recent instruction to train drivers states that from 21 December onwards, they should revert to using the rearmost pantograph. This seems to have some obvious advantages, especially that if some mishap with the overhead wires causes pantograph damage, the lowered front unit will have already passed by safely, and the train may be able to continue by using it. Another point is that carbon stains on the train roof are caused by small amounts burned off from the current collector, and using the rear one will keep this to a minimum area. It is also felt that this will will help reduce the likelihood of damage to the carbon collector head itself, which has been a problem with these trains.

 

[Geezertronic]

There was a thread on Pendolino Pantographs a while ago:

http://www.railforums.org.uk/showthread.php?t=25724

 

[ffcphone]

Noticed a pendo at Preston couple of days ago with rear pantograph raised and thought it odd. Understand why now.

 

[StewieG]

It's the same with using the frontmost Panto though isn't it?

If ya use the first pantograph, the damage to the OHLE is surely going to be the same as compared to the back ?

 

[Geezertronic]

If ya use the first pantograph, the damage to the OHLE is surely going to be the same as compared to the back ?

I think the point being made is that if the back Pantograph causes damage then the theory is that the train can proceed with caution lowering the back pantograph and raising the front Pantograph, and using the potentially undamaged OHL nearer the front of the train?

 

[starrymarkb]

The infrastructure issues were connected with 140mph running and required the knuckle to be trailing. Hence the front pan was used

 

[gregh]

Whilst unloading at Rugeley PS in the last couple of weeks, every Pendo I've seen go by on the WCML has had its rear pantograph raised and the front one lowered, which I guess fits in with other reports here

 

[adamp]

Makes sense actually, gives you more time to lower the pantograph in the situation of an object being on the wires...
-Adam

 

[TGVDUDE]

I believe that TGV's traditionally have the rear pantograph raised. but i think that Class 373's have both up due to the length of the train:

http://www.youtube.com/watch?v=Rne3ZYbGJOQ

 

[90019]

I believe that TGV's traditionally have the rear pantograph raised. but i think that Class 373's have both up due to the length of the train

They have one at each end up because it's two trains forming one set.

 

[O L Leigh]

I think the point being made is that if the back Pantograph causes damage then the theory is that the train can proceed with caution lowering the back pantograph and raising the front Pantograph, and using the potentially undamaged OHL nearer the front of the train?

Nice theory. Not much good if the rear pan has brought down the whole lot and tripped the entire section or the rear pan is hanging over the side, though.

I don't see that it confers any great advantage to operate with one pan or the other raised. The uplift and drag are the same no matter whether the head is facing or trailing to the direction of travel, so the wear rates won't be very different on either the carbons or the contact wire.

I suspect that VWC are just experimenting to see whether they can eke a few more hours of running out of the carbons by swapping the pans over. If so, I expect that they will find that the life of the carbons is virtually the same as it was when they ran with the leading pans.

O L Leigh

 

[TGVDUDE]

They have one at each end up because it's two trains forming one set.

oh right, thanks for correcting