Why Is the Smaller Steam Locomotive In the Lead In Doubleheaders?

That has been generally standard practice since the early 1900s. The main, or "road engine" was selected for it's specific side and power to get the train over the road in most terrain. When the ruling grade is encountered, an additional locomotive is generally added on the front of the road engine. In many cases, a smaller locomotive is sufficient to assist on the steam grade, and then is cut-off at the summit and returned back down grade light.

Thanks! There's my answer.

It appears to have been company policy, such as this excerpt from Colorado & Southern Ry Co. employee timetable #47 (eff Dec 8, 1957), Northern Division:

     "2-10-2 or heavier class engines must not be used as helpers behind caboose. Such engines must be used on head end or coupled in ahead of caboose. When 600 (2-8-0) or lighter class engines are used to double-head, they must be coupled ahead of 2-8-2 or heavier class engines."

     Additionally I have observed photos of Burlington 4-6-4's double-headed with O5b 4-8-4's out of Lincoln, NE, the 4-6-4 always is in the lead.

     Perhaps the locomotive with the greater tractive effort (being the larger of the two) is available for a more continuous pull on the train.

In observing some Burlington steam and diesel double-headers, either with a 4-6-4/Gp7or GP9 and an O5b 4-8-4/SD7 or SD9, the diesel was first, then the steam locomotive was in the lead. In both cases the diesel had more tractive effort (but not more horsepower), so it would appear that the locomotive with the greatest TE was placed closest to the train for the greatest starting power. My best guess......

        In both cases the steam locomotive in the lead, weighed more then the diesel, so it was not a case of the smallest locomotive leading.

Usually the diesel was placed in front of the steamer so that the exhaust from the steamer wouldn't clog the air filters on the diesel.

Stuart

It's mostly about ego.  The big engine can take some humiliation.   

I am looking at a book I acquired on Missouri Pacific steam, and the MoPac had the

Kirkwood hill out of St. Louis in which freights, sent out with Northerns, used 2-10-2's

frequently as helpers to get over the hump.  The 2-10-2's were stationed there, for

that purpose. 

Say what?

"USUALLY"

Not necessarily true. 

Personally, I would like to see proof that the railroads would go through all the time, labor, expense and delays of playing musical locomotives when adding a steam helper to save a couple of air filters.

Rusty

Believe oil burners were operated in front of diesels and coal burners behind.......again, to avoid cinders getting into "the works" of the diesels. My example above of the "Q" steamers teamed with diesels, all were oil burners, operating ahead of the diesels. If you have ridden any distance behind a coal burning steam locomotive, you have seen the considerable amount of cinders produced.

      But, then, there's Rusty's coal burning example above. As was noted many years ago, the moment one says "That never happened", someone shows up the next day with a photo refuting your claim!

I have read That Union Pacific would make a point of placing  a TURBINE in the lead position when double heading with Coal fired Steam Locomotives. The issue wasn't clogging air filters, but rather the damage that the cinders would do to the turbine blades, if the cinders were ingested by the turbine.

This may be the situation that Stuart was thinking of.

Doug

Presumably intake air "ingested" by the turbines would first pass through filters to remove any particulate matter which might serve to damage the turbine blades, such as the desert sands found throughout their regular stomping grounds.

>>Why Is the Smaller Steam Locomotive In the Lead In Doubleheaders?

Gee, I always thought it was because it looks better that way.

It depends a bit on what you mean exactly. In the case of a 'true' double-headed steam train (i.e., both engines were to be used for the entire trip), from what I've read the lighter engine always lead. (No I'm not sure why.) In the case of a helper engine (an engine that would only be used to help the train up a steep grade for part of it's journey) it doesn't appear to have mattered if the helper was bigger than the road engine or smaller. The helper was coupled up front (if it wasn't on the rear of the train) so after the train crested the hill the helper could be easily cut off and the train could continue on it's way.

wjstix, I mean when two locomotives ran the whole trip.

The smaller locomotive would, in most cases, not be able to withstand the pulling stress on the front end, coming from the larger locomotive coupled onto the front of it.

Awe c'mon man! Are you kidding me! I can't believe you would say something like that.

Try to equate that to the fact that small SW-type engines are placed behind massive head end power while being towed.

Generally on the Pennsy, passenger steam helpers were also K4s.   However, if one was not available for whatever reason, an I1 2-10-4 or M1 4-8-2 might be used.   These are both much bigger than the K4 4-6-2, but they would be on the front.   The helper on a passenger train was usually put on the front.    So in these cases the larger engine would be first.  

I can think of no reason for putting the "smaller" engine in the front.  

Again in Pennsy practice most photos show double headers for the whole trip to be 2 of the same class engines. 

I don't know that answer and would love to hear from someone who does.  I can share an experience I had on our family farm many years ago  that might provide a little insight.  We had bought a 6 bottom plow and our biggest tractor could pull it through anything but older alfalfa fields.  At the time, we needed to rotate an 80 acre field so we "double headed" tractors to accomplish plowing it under.  I drove the much smaller tractor and my father the larger one with the smaller one in front.  The ride was rough in front but if I had been behind the larger one, it would have been much worse.  It also gave my father in the bigger tractor control over the plow and stopping if something went wrong. 

I'd think that operating a double headed steam train would have somewhat similar physics and control challenges.  IMHO...

Think double-heading over a 100 mile division would be a different circumstance than providing assistance over a grade, and uncoupling. As Rusty cited, playing musical locomotive chairs with, say, a passenger train probably was impractical.......couple on and off quickly at the bottom and top of the grade, so as to facilitate the passenger train making it's schedule. Maybe even blow some cinders into the innards of a diesel!

      The division long DH move would be different and allow for more cautious placement of motive power. Again, I would re-propose my thought that the locomotive with the greater tractive effort, which would in most likelihood be the larger locomotive, would be placed closest to the train. Additionally, the thought of a little engine being tossed around like a rag doll behind a big engine seems plausible, ala Hot Water's observation. Jack, could you further describe what damage you envision to the engine truck - sorta seems to me it would be floating below the frame. Drawbar, frame damage, torn out coupler pocket, broken coupler knuckle seem like maybes - could you explore further?

       Would think an SW being towed behind a batch of diesels would not be comparable to a steam doubleheader. The diesels would have much greater tractive effort and probaby deliver a much smoother pull. Steam locomotives were subject to spasms of wild slipping, which would send shock waves through the head end power all the way back to the diner and the person with the bowl of soup!!

You would have to pick up a few books and read what the real railroad operations did.

The Northern Pacific used helpers on the rear of a train so it was easier to cut off the locomotives at the summit and head back down the grade in Bozeman Pass near Livingston Montana.

Must have been a great sight to see. Although I bet the guys ridding in that small wooden caboose were very nervous!

Nervous, for sure......that's why the Colorado & Southern required helpers to be coupled in front of waycars (cabooses) !  Looking out the back door of a crummy and seeing that huge locomotive front that might come crashing through at any moment...nervous, for sure!

Could you imagine that all on a railroaders pay?! I have walked and driven the grade and its a long way to the top. Plus its almost a 2 percent grade. Yikes!