What Happens if You Key in to Two Cabs at the Same Time?

[whhistle]

I spoke to a GTR driver today who was complaining about how the cab aircon had failed at one end of his 455. 455s are (slightly) older than pacers I believe.
Or is it there, but doesn’t work without a key on? That’s an issue in our units, also.

Question spurred on from the above.

What happens if you set up one cab, then to go the rear cab and set that up with a different key.
I guess the computer simply won't allow it thus saving a tug of war scenario).

 

[EE Andy b1]

On a Class 390 if you try to use a key in both cabs, on trying to set up the second cab you get a fault indicator (other cab on) and audible alarm.

On a 221 with two sets we were told if you try put 2 keys in together you would probably blow circuit boards and have a demic set. So no no.

On both types air- con works without a key continually if turned on in cab.

The worst thing about air-con on a 390 is going through neutral sections when it stops for about 5-7 seconds then continues.

221 air-con seems to work much better.

But I do like being able to open a cab window at times on a 390, can't on a 221.

Plenty older units still with no air-con at all. Can be very unpleasant at times.

 

[Alteran Ancient]

I've been wondering what might happen in this scenario. On the Bromley North line, they now have double-drivers on board a single 466 during the peak, allowing them to quickly shuttle it back and forth on its peak 15-minute timetable. I would assume that the driver finishing at one end would have to key-off before the opposite driver keys-on - not sure what would happen if both drivers had their keys on at the same time.

During the rest of the day, it goes down to a 20 minute frequency, so I think they ditch the second driver.

 

[TheEdge]

Alot of older BR stock will just lock their brakes on and sound an alarm of some sort if a key is left on in the back

 

[Bromley boy]

Question spurred on from the above.

What happens if you set up one cab, then to go the rear cab and set that up with a different key.
I guess the computer simply won't allow it thus saving a tug of war scenario).

Depends on the unit.

In our older units the passcom goes off if you attempt to key on before the driver at the other end has keyed off (you can tell when this happens because when they move the direction selector to “off” the brakes go into emergency).

Newer units would tell you through the TMS.

 

[D365]

I've been wondering what might happen in this scenario. On the Bromley North line, they now have double-drivers on board a single 466 during the peak, allowing them to quickly shuttle it back and forth on its peak 15-minute timetable. I would assume that the driver finishing at one end would have to key-off before the opposite driver keys-on - not sure what would happen if both drivers had their keys on at the same time.

Presumably the two drivers will communicate through the onboard guard radio?

 

[scotraildriver]

When built Class 170's had a "stabling" circuit breaker which tripped if 2 keys were in at the same time. But it was located in the body end cupboard - a pain to get to especially if the train is full of passengers. So now just a buzzer sounds.

 

[CC 72100]

Alot of older BR stock will just lock their brakes on and sound an alarm of some sort if a key is left on in the back

Continuous buzzer on the BR-era stock I'm familiar with.

 

[EE Andy b1]

I've been wondering what might happen in this scenario. On the Bromley North line, they now have double-drivers on board a single 466 during the peak, allowing them to quickly shuttle it back and forth on its peak 15-minute timetable. I would assume that the driver finishing at one end would have to key-off before the opposite driver keys-on - not sure what would happen if both drivers had their keys on at the same time.

The other thing with a Class 390 or 221 is when you shut down a desk at one end, TASS (Tilt Authorisation & Speed Supervision) has to again go through it's self-test before you can open the desk at the other end or TASS and Tilt will not setup and brakes cannot be released but not a problem normally due to turnaround times.

 

[GW43125]

Presumably the two drivers will communicate through the onboard guard radio?

Or they watch for the "other cab on" light to go out- do the networkers have these?

 

[Bromley boy]

Or they watch for the "other cab on" light to go out- do the networkers have these?

Nope. The passcom sounds if two keys are on at once.

 

[theageofthetra]

Nope. The passcom sounds if two keys are on at once.

And on Metcam 465/6 the brake control MCB can trip in both cabs.

 

[ComUtoR]

Presumably the two drivers will communicate through the onboard guard radio?

You can tell when they take their key off without any communication.

 

[whhistle]

Thank you all.

 

[OxtedSignaller]

On a 377 it causes chaos it trips out MCBs and throws the train right off. Obviously it shouldn't happen but it does occasionally usually when coupling and uncoupling and there has been a miscommunication. You would think modern rolling stock would be built to bring an error message up and allow you to take the key off instead of wrecking the train.