Top and Tail

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Oswyntail

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This prompted by a photo of two 66s at either end of a works train.You see this all the time, but I have never stopped to wonder how it is done.
When this happens, do the locos operate independently or do they have some control system link? Or is it done by radio communication between the drivers? Is this the same in eg railtours, or do they use some sort of through-wired multiple working?
And, if there is a driver in each loco, which cab does the rearmost driver operate from?
 
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Hydro

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It's not done (in terms of both engines powering), in most cases. Top and tail generally means that the rear most loco is hauled "dead", and not powering - this set up is used on engineering trains because it negates the requirement to run the loco round as moves within engineering possessions can be quite complex. If the rear most loco has to be left running, for ETS purposes on passenger trains for example, a second driver must ride on the locomotive to monitor the fire system. Normally the rear loco doesn't provide assistance.

The only train to my mind that runs normally top and tailed with the rear loco powering (and no through cabling) is the HOBC, and the drivers stay in contact via radio link. I'm quite sure the same applies to trains requiring banking.

Test trains are run as push-pull, generally. All test trains have through cabling and pipes for Blue Star working. This means that no rider is required on the rear loco, as the fire system is piped through the train via the cables, and that both engines can work in multiple. As long as the electrical connection through the MW jumpers is sound, then no-one is required on the rear engine.
 

Hydro

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American Association of Railroads. The American standard for things like couplers, electrical systems, multi-working etc. AAR MW is found on Cl.66, 67 and 70 - all of which are based on American designs.
 

DownSouth

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I think you meant 0.47 miles long!

Locotrol is even cooler than Blue Star or AAR, try eight 4,700 kW GE locos distributed through a 19 km train with 682 iron ore wagons, all without fiddling around adding anything special to the wagons. It's so good that locos are now being delivered to Australia without cabs, only electronics cabinets with the Locotrol gear.
 

marks87

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I was in Glasgow the other week when the Northern Belle was leaving Central station, and the 47 on the rear sounded dead, but had its tail lights on (but still had a flashing tail lamp as well).

Is it likely it was just idling on the rear, to avoid having to power it up from cold when needed.
 

deltic1989

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Trains can still have their lights on without them running AFAIK
I would be inclined to agree with you, as they are IIRC required to show red lights to each end when parked in a siding or yard. there certainly seems to be a few dead units showing lights at Eastcroft every time I pass.
 

Schnellzug

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Trains can still have their lights on without them running AFAIK
I don't know if it is actually a requirement, but if a loco's just hooked onto the back, They'll usually put a flashing tail lamp on the back just to be on the safe side. If it's pushing then it'll have its own tail lights on.
 

Ploughman

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Frequently with Top and Tail working of engineering trains.
If there are multiple trains all working on one site, like a couple of spoil trains, some bottom stone trains and maybe a few others.
The last train would be T+T then at some point during the possession all the locos on the trains except the first will uncouple and move forward and couple on to the train in front ready to return the trains out the way they arrived. With the first train to arrive being the last out and working T+T.
 

GB

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Even with the rear loco running, with a top and tailed train using the class 66 there is no requirement for the rear loco to be manned.

Top and tailed can work in 3 different ways.

1- The rear loco is running and provides power and brake assistance with two independent drivers with radio link as already said.

2- The rear loco is completely shut down and isolated and provides no assistance. In this mode a battery operated taillamp must be placed at the end as one some locos the built in lamps won't work and the ones that do will drain the battery.

3- The rear loco is running but the brake control unit is isolated and engine is isolated and provides no assistance. As the engine is running the built in tail lamps can be used. This is the most common type of top and tailing.

The same processes apply with double heading.

With points 2 and 3, the rear loco effectively becomes just another wagon.
 

BestWestern

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American Association of Railroads. The American standard for things like couplers, electrical systems, multi-working etc. AAR MW is found on Cl.66, 67 and 70 - all of which are based on American designs.
How depressing! :( Class 47 anyone?!
 
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