Diesel Loco Deadman systems

I would like a bit of help and I am sure that someone out there can help me.


When I was driving Southern Electric Slam Door stock a deadman system was fitted on them that simply involved pushing down on the regulator handle whilst the train was being driven.


If the handle was released, the brake would activate and the train would be brought to a halt. Most drivers knew that the train could coast in neutral and the deadman was not active. So the handle could be released. Allowed a little relaxation to the arm. Not a good practice I know, but Hey Ho! What health and safety?


I am writing a book and am trying to keep details accurate. I don’t want anyone contacting me and saying, “That could not happen”


My book involves a diesel loco being driven with the deadman being defeated. In the book, the loco is moving without a driver being present.


Are there any preserved diesel locomotives that would have a similar deadman system? Either a foot pedal or a handle that needs to be held down without a vigilance system being involved.


Which class would have such a system and what would it be?


Thanks in advance.

 

Certainly when I was on Diesel-Electric loco maintenance in the mid-1960s Classes 24, 31, 47, 55 and DP2 all had a foot pedal that needed holding down acting as a deadman system

 

The driver in the Southall accident was accused using his bag to depress the deadman’s pedal in the HST powercar involved.

See p.28

https://www.railwaysarchive.co.uk/documents/HSE_Southall1997.pdf

 

Are Tampers etc fitted with a Handle?

 

But wouldn't this only give a driver around a minute's respite?

The pedal has to be released and pressed again every minute so a bag would only replicate the interval when it should have the weight of a driver's leg depressing it.

 

They do now, yes. But until probably the 80s the handle merely had to be depressed - there was no timer relay fitted. GN class 313s went for scrap without a timer relay being fitted, so it was perfectly possible for a driver to put his bag on the DSD pedal for the whole journey. The power handle was also sprung and operated a microswitch in the same way the DSD pedal operated.

Coasting in neutral, at least on EMUs, hasn't been possible for a long while, as there is usually a speed switch that will kick in if the speedo gets above a certain speed with the master controller in neutral rather than forward or reverse. No idea about locos though.

 

Thank you all for the replies you have all given.
A question for Eightpot, who mentioned quite a few classes of loco, Would the pedal on a 31 or a 47 need to be released and then reapplied about every minute to keep the system from applying the brakes?
As has been mentioned by 5944 some classes may have been modified, such as HST power cars. In the book I am writing, I had thought of the locomotive being a 31 or 47. Definitely not an HST. Had not thought of a Tamper......hmmm, very interesting! But probably not!
Could any loco come into preservation stock with an unmodified system?
Southern Slam Door stock when I was driving in about 91 to 93 could coast in neutral at any speed.

 

I suspect a lot of first generation diesels will have entered preservation without being modified. Put the controller in engine only and you don’t need to depress the dead mans pedal/handle. You can’t get power but you can release the brakes and coast.

 

Most locos, but not all, were modified with SSF which applies the brakes if 5mph is achieved and the DSD isn't pressed, irrespective of the position of the controller. Plenty in pres have SSF.
However there are circumstances where runaways can happen. If a loco is left without the handbrake on or chocks inserted and the engine isn't running , once the air leaks off then it will gently roll away on its own (which has happened and the circumstances can be found on the RAIB site). A first-generation DMU can run away if the driver mishandles the brakes and looses the 'top-side' vacuum (as has happened at Stourbridge more than once), air-braked units have been known to run away because brake isolating cocks have been inadventantly left in the isolated position (Pacer at Liverpool?), complete trains have run away because the brake cock has been closed between loco and train meaning that there is insufficient brake force left to stop it (see the recent Edinburgh Waverley incident and I believe a similar one in Carlisle some years ago) and of course in the old days unfitted goods trains could run away if mishandled.
Plenty of opportunity for your book I would have thought!

 

Thank you again for the replies.
Without giving too much away, the circumstances in which the locomotive runs away in my book is that a light diesel has just been used to run from a depot to a station by a bunch of unsavoury characters. Having stopped they want to wreck it by starting it running and jumping off.
Hence no good if it reaches 5 MPH and stops. Also no good if it runs for a minute and the vigilance system cuts in. The brakes would not have much chance to leak off either. I want it be able to start with the DSD having been either tied down or a weight put on the pedal and no vigilance system to cut in or the have that part isolated. Must be a loco and not a DMU.
I need to know what class of loco it could be to suit the circumstances. No good if I write it as a Class 47 for instance and then get jumped all over with comments saying it could not happen on one of them but a class 45 (or some other class) could have done it!

 

At that time (1960s) one held the pedal down all the time. If released when moving under power there was a time delay - from memory about 10 seconds - before power was cut and the brakes applied. Having to release and re-apply pressure to the pedal at (one minute?) intervals came later.

 

Slightly OT with regard to the original question, but I've often wondered why the original device was ever considered to be a satisfactory answer to the problem of an incapacitated driver, given the possibility of them still having weight on the pedal or handle after collapsing or whatever.

I can only assume it was not given serious consideration because locos were almost always double manned.

Perhaps only when single manning became not only permissible but the norm was a serious effort made to ensure the drivers vigilance device actually worked?

 

Yes, I often thought that if I had had a heart attack or something like and fallen on the handle, it would have been of no use at all!
Still looking for a loco class I can use.

 

I believe there was an accident where the driver of a dmu had a heart attack and his weight kept the dead man's depressed.

Edit https://www.railwaysarchive.co.uk/eventsummary.php?eventID=360