Steam & Excursion > Double Heading Steam Locomotives on Passenger Trains

Can someone please explain the connections between double headed steam locomotives on passenger trains? I am specifically interested in the air brake lines and train heating lines.  
For example, did both locomotives provide air and steam? 
I assume that only one of the locomotives, probably the lead engine, controlled the train brakes, but did both supply air to the system? 

This topic is of great interest to me as I made a statement in my book "Canadian Pacific Railway on the Revelstoke Division Volume One" that may be erroneous. I want to write a retraction if necessary to include in volume two.

Todays distributed power changes the rules, but ....
Only one locomotive, in steam days, can supply air to a train.  Normally, this is the leading locomotive.  That said, there were many instances of only the second locomotive supplying the train air in helper districts, where the lead locomotive would be cut off "on the fly", without having coupled the air and without stopping for cutting off.  The fireman simply climbed over the coal pile and down the back of the tender to pull the pin.  The helper then ran ahead to the next switch and ducked in, out of the way.

Steam could be supplied by one or the other engine if you have the piping connections, or both.  Helper engines often did not have steam piping, and had to be used as lead engine, or pusher at rear.  In any case, steam connections, unlike air, cannot be cut off on the fly - you have to get down on your hands and knees with a hammer to undo it.

-LD



Edited 1 time(s). Last edit at 11/24/18 09:55 by LarryDoyle.

LarryDoyle is correct and more experienced than me.

But, most often the only hose connections between the two ( or more engines) was the ‘trainline’ air hose, and perhaps the
conductor’s signal line ( small air whistle in the cab).

Typically, when the trailing engine’s brakes are cut-out, we mean the automatic brake stand and it’s handle are turned off.
This prevents the air supply from the second engine from reacting to a brake pipe reduction....by trying furiously to re-supply the reduced air pressure....only one brake valve can control the trainee line pressure.

( on MU’d diesel units, the Main Resevoir lines are connected to keep the lead locos Main Reservoirs fully charged.
two other small brake lines directly control the trailing locos truck brakes ( the ‘Independent ‘ brake valve) .

When in trail ping postion, the trailing loco’s brake cylinders will be pressurized by the actions of the lead loco’s Automatic Brake Valve.  Steamers DO NOT ‘MU’ the control lines of the driver brakes .....HOWEVER, the loco ‘ control valve’ can react to a reduction in brake pipe pressure and attempt to apply the trailing loco’s brakes, like a regular freight car.

That ‘automatic’  application, is restricted in its ‘sensitivity” to gradual brake applications...
The engineers on trailing locos, monitor their driver bikes very carefully..... if the brakes on trailing locos, attempt to apply the engine brakes, the engineer’s on the following locos, separately, release the brakes on their active independent brake valves.

Diesels give that control ( through additional hoses) to the engineer on the leading unit.

On trsiling steamers, it’s very important to keep their driver brakes from applying during station stops or long descending grades...
thus the trailing engineers will constantly release the air that may try to build-up in the driver brake cylinders 

Heated driver tries and expand and loosen their grip on the wheel centers.... such loosening can cause derailments...

Now you know... [ there are ALWAYS different practices that require alterations to the written practices and procedures.]

​W.
not proofed, yet...

Steam operation and double-heading over Cuesta was an every day operation. 

First off, the helper usually went on the point on passenger. They were not allowed to shove a passenger train unless it was under the Superintendents signature be it steam or diesel.

With the helper on the head end, that crew had to be qualified passenger. If they were not, they had to trade places with the road crew who were.

The lead engine had the air. Also, the signal line was to be connected if equipped. The steam train heat was taken care of by the road engine to save time when the helper was cut off.  

Double heading wasn't much different except the lead engine was usually the road engine.


Nudge

Thanks to all who replied. Your answers were very helpful. For reference, I've attached a jpeg of the page from my book. My take from your answers is that my comments under the photo are partly correct. A second locomotive may have been added in some situations to supply steam to the coaches, but definitely not air. I should have asked before the page went to the printer. I was nervous about the page, but none of my expert proof readers caught the mistake. I should have listened to the voice in my head and done more research. Or changed the text. Now I have to add a correction in the introduction of volume two. Thanks again.

 

---

Train heating steam was almost always supplied by the second locomotive (which was usually the road locomotive) as very few steam locomotives had steam connections on their front end.  About the only place you would see it was on some commuter locomotives, particularly tank engines, that would sometimes run backwards at the head end of a train.

Gordon



Edited 1 time(s). Last edit at 11/25/18 06:20 by gbmott.

I know the lead engine controlled the brakes, but I wonder if the question was could both engines provide air?   On our Texas BNSF EAS trip, we had a "billboard" diesel behind 1522 and just let it furnish main air res pressure instead of wear and tear on 1522's pump.  There's no reason we couldn't have used both if we were looking for faster recovery from a brake app.
We did have MU controls and connections and had a main air res line between the diesel and 1522.



Edited 1 time(s). Last edit at 11/25/18 07:28 by Frisco1522.