What does that cable loop on the end of a class 56 do?

[Topgun333]

Apart from reminding me of the Droopy Dog cartoon character, what does that cable loop do on each end of a 56?

Always wondered, never asked...

 

[Murph]

Apart from reminding me of the Droopy Dog cartoon character, what does that cable loop do on each end of a 56?

Always wondered, never asked...

That will be the multiple working cable, I believe. Plugged into a dummy socket when not in use. It's to control multiple locos coupled together at the head of a train, when a single loco would have insufficient tractive effort or power.

 

[Topgun333]

That will be the multiple working cable, I believe. Plugged into a dummy socket when not in use. It's to control multiple locos coupled together at the head of a train, when a single loco would have insufficient tractive effort or power.

Thanks Murph.

Why is its positioning and/or visibility so unique to a 56 then?

 

[Murph]

Why is its positioning and/or visibility so unique to a 56 then?

Not all that unique. It's pretty much identical on the 58s (which are compatible with the 56s). Also high up and quite visible on 33/1s, 73s, 442s, etc. In the case of those passenger locos, it's also used for remote control from a driving trailer in push-pull operation.

Some locos and units have the cables high up, others have them down around the buffer beam. Not really sure why some are high, others are low, just choices made when designing them or ordering them, I guess. High is out of the way, but needs someone to climb up from track level (if not adjacent to a platform); low is possibly more prone to damage, but easier to couple at track level.

 

[33056]

High is out of the way, but needs someone to climb up from track level

And is more easy to forget about / overlook when uncoupling at track level

 

[dgl]

the height on 33's, 73's, 442's, SR EMU's Etc. was due to 3rd rail electrification and SR wanting to avoid having to have a shunter working so close to the 3rd rail. (All SR EMU stock was like this and therefore so were their locos that were designed to be used them)

 

[HSTEd]

And there was much fun when people tried to decouple trains from the platfrom but then discovered that the jumpers had been connected on the wrong side.