• Question on operation of Helper Engines

  • Pertaining to all railroading subjects, past and present, in New York State.
Pertaining to all railroading subjects, past and present, in New York State.

Moderator: Otto Vondrak

  by Fireman43
Question really not pertinent to this forum but requesting some explanation on how pushers are utilized.

1. When i see info on steam pushers being used - ie- on the Elmira branch's coal runs they used engines at the rear.

2. Watching a show now on a present day 1.6 mile long iron ore train of 24,000 tons running from a mine operation in Upper Canada. Mentions 240 cars being pulled by 2 engines but then has a "helper" engine 2/3 of the way back.

I presume the crew of the pusher would know from experience and 'feel' how much push ( for lack of a better term) but the helper in the middle the ore train was presented as unmanned. If so i suppose again, was controlled electronically from the lead engine?

Curious how everything is coordinated between crews /engines.


  by BR&P
You are essentially correct on both counts. The unmanned helpers or "distributed power" are controlled electronically from the head end.

And pushers - steam and diesel - relied heavily on experience of the crew. There are too many variables from railroad to railroad, from place to place on a given railroad, and from one train and crew to another - to give simple explanation for everything that went into it. In SOME cases, it was indeed just a case of "get behind and give her all you've got". But factors like undulating grades, curvature, where loads and empties are placed in the train, the relative power available from the head end vs. the pushers, etc, often dictate finesse and "seat of the pants" input rather than just balls-to-the-wall throttle.

One other thing to mention is that in more modern times both the head end and the helpers would have radio communication, making teamwork and coordination far easier.
  by tree68
It's important to note the difference between a helper and a DPU (distributed power unit).

Helpers are manned. They are usually added to a train only where needed, then removed when no longer needed. If a given locomotive consist can handle its train over all but one grade on its route, it will run only with that power until it reaches that grade (or the general area thereof). The helpers will be added, assist the train over the grade, then be cut off (or out, if they were added mid-train) and will return to the bottom of the grade to wait for the next train needing assistance.

These days, DPU's tend to stay with their train from origin to destination. There is no crew on board. If their assistance is needed, the engineer can bring them on-line (via a radio link) and put them to work. If the head end power can handle the train, he can throttle back the DPU. I just saw a chart showing the advantage of putting the DPU two thirds of the way back in the train. This helps spread out coupler strain, and would be a reason to keep the DPU working most of the time, even on relatively flat country.
  by Spike1724
I have run helper engines many times. The main point that I take into account is to not push too hard, which might make cars derail, especially if they are empty. My main goal is to just take enough load off of the lead consist so they pull what they are able to, while I mainly am pushing the excess.

Sometimes the helper and head end crew talk, but mainly the helper watches the gauges. The brake pipe is connected to the train, but the helper’s valve is cut out. By noticing when the head end makes a brake application, for example the helper engineer can start backing off a little. When a train is going along with a pusher the slack is stretched to a certain point in the train. From that point it is bunched. The part that is bunched is whatever the pusher is contributing. This is where my point above comes in about letting the head end pull what it can, while the helper handles the excess. Normally if the train has to stop, then the head end pulls its portion to a stop. The pusher likewise pushes to a stop. That way slack is where it is easiest to restart. If the stop is to cut off the helper, then the stop is planned to be where the train is balanced over the crest of the hill. If the helper stopped with the slack pushed in, then when the helper cut off, the tail end might want to try and run out backwards. To avoid this the helper slowly and gradually reduces power until the slack is stretched through the entire train. One time I was on a unit coal train, and the helper engineer wasn’t too cooperative. He kept pushing right until we stopped. Somehow I was able to restart the train without having the slack run out and break a knuckle. I think I waited for the helper to cut away and head back down. I released the brakes, but then made another quick but light application. This let the slack go back out gently. Once the slack was how I wanted it, I then recharged the air. I was OK because I had the train balance over the summit. When I felt the air was recharged enough then I went down the other side.
  by ExCon90
Every time I read about automated operation of freight trains I wonder how they're going to handle the role of braking in train handling.
  by Fireman43
Interesting info. from those who have been there, done that.
So I guess when you were operating a pusher really no time to enjoy the passing scenery, head out the window , wind in your hair.
All joking aside, talk about nerves and on the edge of your seat.
I applaud you .
Thanks for your info and background.
  by TrainDetainer
Spike's description is dead on, but I'll add a couple of details. Remember that engineers are qualified on the physical characteristics of the route and know every little undulation, curve and all the other little things that affect train handling. You know when a little less or a little more throttle is necessary or advisable to keep that slack point from moving drastically. On communication, of course today we have radios and the engineers can tell each other immediately when to lean in or when they're easing off or braking, but in the old days whistles and brake pipe activity was the only way to 'talk' over distance - a little easier then as the trains were shorter. And not every railroad had rules back then about connecting the brake pipe - many railroads had helpers cut off on the fly without stopping the train (today the controlling loco is required to be in control of the whole train's brakes, including helpers). If you ever looked close at a fully rigged caboose, you'll note there's often a light chain running up from the coupler pin to some point on the railing - it's for uncoupling on the fly.

ExCon - Most of the slack action can easily be removed with two things - tight lock couplers and ECP brakes. With only the slack of cushioning devices and computer monitored braking condition/effort, things get a whole lot easier. It's a simpler game of power vs. gravity.