Azuma running with raised pantograph at the rear

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Prestige15

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I've noticed that recently im seeing a good number of 9 and 5 car (solo) with the pantograph raised at the rear rather than the usual front, Any reasons behind it?
 
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zwk500

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I thought rear was the normal one to run with so that if it strikes something and detaches (or parts detach) it won't hit the spare pan.
 

Bletchleyite

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I've noticed that recently im seeing a good number of 9 and 5 car (solo) with the pantograph raised at the rear rather than the usual front, Any reasons behind it?

I don't know about 80x, but on the Pendolino the rear one is always used, the reason being that if it gets entangled in the OHLE and is damaged, the front one will still be usable provided the wire is. Whereas a damaged front one could send debris/wire damage back and wreck the rear one.
 

Prestige15

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I don't know about 80x, but on the Pendolino the rear one is always used, the reason being that if it gets entangled in the OHLE and is damaged, the front one will still be usable provided the wire is. Whereas a damaged front one could send debris/wire damage back and wreck the rear one.
I'm guessing the Azuma's at least are starting to do the same, It also probably explains why TGV sets mostly have their pantographs at the rear when on high speed line.
 

Nym

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I don't know about 80x, but on the Pendolino the rear one is always used, the reason being that if it gets entangled in the OHLE and is damaged, the front one will still be usable provided the wire is. Whereas a damaged front one could send debris/wire damage back and wreck the rear one.
Actually more to do with dirt on the roof line than that.

If there is a de-wirement, the chances are the tension is all gone anyway so raising the other pan wouldn't get you anywhere, if indeed you even were permitted to do so.
Same dumb logic that put last mile engines in electric IEPs, driving out from de-wirements that you realistically wouldn't be able to manage operationally anyway.
 

DanNCL

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The 80x had, until the last few weeks, normally ran with the front pantograph raised, usually only using the rear pantograph if for whatever reason the front pantograph can't be raised. In the last few weeks I've noticed most LNER units using the rear pantograph instead, but the TPE 802s still appear to be using the front pantography.

I suspect an incident last December in Northumberland where the pantograph got tangled in the wires, dragged the wires down and resulted in the windscreen being smashed may have something to do with this change.
 

class ep-09

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I've noticed that recently im seeing a good number of 9 and 5 car (solo) with the pantograph raised at the rear rather than the usual front, Any reasons behind it?
There could be few reasons :
Rulebook requires “drop and stop “ if train looses line light ( or open VCB is indicated ) , one attempt to restore it ( close VCB) is not successful and pantograph is further that first 3 carriages from the front .

If pantograph is raised at at front 3 carriages it is “ drop and coast” to suitable location to asses situation ( or change to diesel and drive to such location) .

Perhaps LNER decided that rear option is better as it gives time ( very little though at 125mph) for a driver to “drop the pan “ ( at rear) in case of damaged OLE being spotted in front to prevent pantograph being tangled .
As far as I know LNER runs mostly under head-span wires, which are easily to be damaged over more than one track if pulled down, and any chance to avoid it is a good choice.

GWR 8xxc as a default set up run with front pan raised , when changing from diesel to electric .

Considering that the electrification at GWML is mostly independent over each line , there is limited number of locations, where damage can be serious if wires pulled down ( some head-span between Paddington and Airport Jn still exists), allowing “ drop & coast “ to “get out of the way” approach to be used if line light is lost ( VCB open).

There is also issue with running in multiple (2x5).
The only configuration that 8xx are allowed to run at 125mph is if the frontmost and rearmost pantographs are raised .

That is also how the sets are configured and it makes mistake ( failing to reconfigure pantographs after coupling for example ) or intentional intervention ( to isolate damaged pantograph) to have different pantographs raised in multiple .

Any other configuration speed needs to be reduced to 100mph ( if pantographs are raised on either 5th & 10th or 1st & 6th coach) or 80mph if pantographs are raised on 5th & 6th.
That is due to the OLE tension / oscillation / bouncing .

Having one simple instruction ( front pan always up ) may prevent some of the issues.
 

Mag_seven

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I've noticed that recently im seeing a good number of 9 and 5 car (solo) with the pantograph raised at the rear rather than the usual front, Any reasons behind it?

Oddly enough I was on a southbound LNER "Azuma" on Sunday night and noticed just that. As has already been stated that is not the case on GWR where it is always the front pan that is raised on a single set (5 or 9 car).
 

D365

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I was under the impression that it was always planned (and intended) for Class 80x units to operate using the rear pantograph, unless coupled in multiple where it is front and rear.
 

greatvoyager

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I was under the impression that it was always planned (and intended) for Class 80x units to operate using the rear pantograph, unless coupled in multiple where it is front and rear.
I was under that impression.
 

Bletchleyite

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Same dumb logic that put last mile engines in electric IEPs, driving out from de-wirements that you realistically wouldn't be able to manage operationally anyway.

Surely that isn't about the actually de-wired unit with OHLE all over it, but rather the ones either side of it which have lost power but are otherwise totally unaffected?
 
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