Cold Starts.

[Master Cutler]

A question mainly for the drivers/ex-drivers regarding the winter months.
There are loads of "clag" videos of Diesel cold starts where locomotives need to be warm before moving off.
My question relates to the electrics, what warm up if any does an electric locomotive need, during say sub zero weather, before it can move off?

[Beeyar Wunby]

Originally Posted by Master Cutler

A question mainly for the drivers/ex-drivers regarding the winter months.
There are loads of "clag" videos of Diesel cold starts where locomotives need to be warm before moving off.
My question relates to the electrics, what warm up if any does an electric locomotive need, during say sub zero weather, before it can move off?

AussieSteve is the loco man, so I'm sure he'll give you more detail on those than I can as I drove EMUs, but I'll stick my 2p in anyway.

I believe the big issue is whether the unit in question has been sitting on the juice all night, or whether it's been cut out. If it's the former, then it should be warm and full of air - so pretty much ready to go. Certainly a modern one. I'm told however that on some of the older Slam Door dc EMUs of the Southern/South Eastern, the air compressor didn't run if the driver's key was not in the desk (which it shouldn't be if the unit is unattended), so you would have to wait for the air to pump up before you moved it. About a 10 minute delay if all worked properly. Also these old units had a manual parking brake. It was located on thd 2nd man's side of the cab and looked like a ship's steering wheel (some passenger's have actually asked me "why does that thing have a steering wheel, you guys don't actually steer do you?") . I mention this because in really freezing weather the parking brake could have frozen on. In which case, time to call the fitters out.

In the second case, where a traction unit has been cut out overnight, things can be a real pain. If you remember your schoolboy chemistry, the speed of a chemical reaction is proportional to the temperature. A battery is just a big heavy bucket of chemistry, which handily can produce electric current. On a stinking cold day it just doesn't want to do its magic. We need the battery to get our unit connected to the juice. Firstly to close the massive Master Circuit Braker, and secondly to either lower the dc shoes or raise the ac pantographs. This is done by air, so we need the batteries to operate the compressors. That's a big ask, and often it doesn't happen - so fortunately there's a Plan B and a Plan C. Plan B is that often there is an "auxilliary compressor" located in a dark corner. We can go to it and manually toggle it to run. This is a little low-power device which doesn't feed air to all the big brake reservoirs or other systems, ONLY the pantographs or shoes, just to get the unit on the juice. Plan C is Thunderbird Rescue time. Hopefully somewhere nearby is a unit that is still running on the juice. We'll hook it up to our unit and pass air through their Main Res Pipe to ours, so we can get our pans up / shoes down .

Sounds great, but often we are subjected to overnight isolations, where a whole area has the juice switched off to allow linemen to work on the power supply. In this case there isn't a unit anywhere to provide donor air. In which case all the drivers and shunters retire to the lovely warm messroom, whilst a poor Fitter drives 50 miles through ice and snow to come and rescue us. Usually when they phone to say they're on their way they're told, "Take your time mate and drive safely, we've got a card school to finish here."

Cheers, John

[Master Cutler]

Many thanks John.

[pre65]

Another informative and interesting question/answer.

Thanks to MC and John.

[Beeyar Wunby]

You're welcome guys - it's a good question.

[aussiesteve]

G'day,
I am not sure that our down-under cold weather would pose many dramas to electric traction.
As BW states, Flat batteries during winter would be the main drama when buzz boxes are stabled off the air (overhead).
A domestic car battery will kark it here during winter if the vehicle is not utilized regularly.
Or a battery charger not connected occasionally.
And condensation in the air brake system might also cause a minor problem regarding frozen brakes.
It did get COLD in Lithgow during winter, but nothing like you Poms cop, and indeed weasels required a long warm up period before they were able to perform.
Mostly, our buzz boxes were left on the air while stabled, unless trackwork was scheduled and buzz boxes were not required for a couple of days.
But as privatization loomed, our buzz boxes were kyboshed in preference to weasels.
Working electric traction during winter, either buzz boxes or emu cattle trains, did provide some spectacular fireworks off the overhead.
Arcing being very prominent as the pans hit any dangling icicles.
Pumping up the pans when no main res air remains is fun (HA!).
The Metro Vickers 46 class buzz boxes had a three way marine air tank to store air to later pump up the pans.
But, the things either became useless due to being out of use by date.
Or crews forgot to store air in em prior to stabling and dropping the pans.
Yes, so go grab another loco to pump some air into the dead thing main res tank.
Then hope that once you have the pans up that there is enough battery juice to get the thing to fire up.
I was sent down to smog hollow many moos ago with me driver to fire up a stabled coalie in Penrith refuge.
Then work it home to Lithgow.
We got down there with heaps of time, but me driver suggested that we visit a rellie of his nearby for a cuppa java.
This was PRE dawn.
His rellie was NOT impressed, but made us a cuppa java.
By the time we got back to the refuge, we only had about 30 minutes to get the thing going.
It had been stabled for many hours pans down and all the main res had leaked off.
Both of the 86 class buzz box pair of foot pumps had ruptured seals and achieved nada.
We could not get a single pan aloft.
PANIC.
So, I ran down to the station to beg the control officer to borrow one of his suburban squirts.
They did have one emerging from the yard which was not due away for a while.
So, with the co-operation of the pointcop, we maneuvered the emu up and into the refuge close enough to hook up the main res hoses.
Hallelujah, we finally had some air and could get the pans aloft.
The batteries were ok, so they fired up.
I then had to sprint along the train releasing hand brakes and to the rear to perform an air brake continuity.
Sprinting back, we were just ready for the scheduled departure.
Yes, the cuppa java was nice, but I paid for it being in a lather of sweat for most of the trek home.
Me driver knew not to ask me to do any of the driving, I sat there in my seat recovering.
Ah them good ole days.
Steve.

[Master Cutler]

Cheers Steve, another great account.
Regarding the Pantographs and the cold, I suppose there's something to be said for third rail supply in extreme conditions.

[pre65]

Originally Posted by Master Cutler

I suppose there's something to be said for third rail supply in extreme
conditions.

Probably not as I understand third rail icing up can be a serious problem.