mu"ing steam locos

how was multiple engines controlled back in the day ? today we connect 27pnt jumpers ,were other steam locos ever remotely controlled from one location?

In days of yore each steam locomotive had their own crew of engineer and fireman; there was no way to control two locomotives from one cab. In the event of doubleheading both locomotives were crewed, yet another justification for diesels. Before radios the engineers would 'talk' to one another via engine whistles. I have it on good information that, late in the steam era, when doubleheaded Nickel Plate Road Berkshires would pass Lima Locomotive Works someone would yell "they're MUing!"

interesting info thanks for the reply,another example of why less manpower is needed on todays rr(amazing how one jumper can replace a crew)

Amplifying D. Carleton's reply: operating a steam locomotive was typically a two-person job. Even with automatic stokers or oil firing (to eliminate most of the actual SHOVELING of coal), the fireman was needed to monitor the operation of the boiler (check the water level, check how the fire was doing and modify the stoker settings if necessary). There were experiments (by Baldwin Locomotive Works in the 1930s, I think, and by Norfolk and Western in the 1940s) to automate this, at least on switch engines, to permit one person operation, but I don't think this was ever done much in practice. The ACE project to build new, diesel-competitive, steam locomotives for freight service in the late 1970s (after a sudden major increase in oil prices) envisaged fairly sophisticated (electronic, I assume) control systems to eliminate the need for a trained fireman on board.

1930s/1940s technology could surely have managed a system by which the "throttle" (actually a combination of throttle and valve-gear) settings could have been remotely controlled on a trailing "unit", and I have occasionally fantasized about a "semi-m.u." arrangement of steam locomotives in which an engineer could control the operation of two or more locomotives, with only a fireman in the cab of the trailing "units": 3-person operation for a double header instead of 4. But I have never seen any suggestion that anything like this was actually attempted in the steam era.

In more recent times, some steam locomotives HAVE been equipped with equipment linked to the throttle that generates and sends m.u. control information, so the engineer of a steam locomotive can control trailing diesels by m.u. (Done sometimes to allow a smallish steam locomotive to "pull" a large excursion train.) But I don't know of anyone having operated a steam locomotive as the "remotely controlled" part of an m.u. pair.

Yes # 4449 and # 844 can operate following diesels via MU connections. They could not be MU'd together and operated as one. They would require a crew for each engine, with radio contact between the two for MU'ing. In the "old" days, each steamer required a crew to operate in multiples. A steam locomotive is essentially completely mechanical in operation.

Indeed, when 4449 and 844 doubleheaded in 2007, they each had a crew. I think when 4449 is mu'd with a diesel it is mainly to have access to the diesel's dynamic brakes.

Not really. The problem is when they have an excursion for # 4449 people come out of the woodwork to ride behind her. So the train gets quite long, and requires additional horsepower. Hence, the additional diesels, usually adding up to at least 6,000 hp. That ensures no problems with climbing, acceleration, and stopping.

You aren't giving the big steam engines enough credit, Pennsy. The 4-8-4s were designed to pull long passenger trains at speed, and they still can with no trouble, unless they have a steep mountain pass to cross. The Daylights 4449 was deigned to pull were up to 20 cars long, and 4449 could and did pull the 26-car Freedom Train unassisted when no steep grades were involved. (Video Evidence) I've personally seen 4449 pull a 17-car excursion train up the Columbia River Gorge unassisted and with no trouble. When 844 arrived in Portland to meet 4449 for the 2007 doubleheader, it was unassisted with 18 cars.

I don't know where your "adding up to at least 6,000 hp" idea comes from. The only time I can think of 4449 having more than one diesel helper is when a railroad's helper set was added to cross mountains, such as the Cascades, and even then, that was just for the pass, and the helpers were always in pairs; one diesel might have been enough. Usually, if 4449 has diesels at all, it's just one. The Montana excursion had a single 3,600hp F45. The trip to Michigan had a single 4,200hp Amtrak P42. I don't think I've ever seen 844 or 3985 run with that much diesel power either, unless it's a special move with the E-units or Centennial.

I'm not saying the diesels aren't doing any of the work; if there's a steep grade it may be necessary and the rest of the time its probably pulling a little so the steam locomotive doesn't have to drag it around as dead weight, but it isn't neccesary for the steam locomotive to pull the rest of the train most of the time. But access to the diesel's dynamics puts less wear on the steam locomotive's and cars' brakes, and the presence of an Amtrak diesel may be necessary just to provide HEP for the cars.

Leading to a question...
Steam locomotives develope their greatest power at relatively high speeds, but diesel electrics can (subject to adhesion limitations at very low speeds) put out full power at quite low speeds. So, a combination could have been useful: a diesel that didn't add MUCH at high speeds could have been a very helpful "booster" when getting started or climbing hills. To give an example that COULD have been (but as far as I know wasn't) tried in the U.S. in the steam-to-diesel transition period: a 5,000 hp 4-8-4 with a 1,500 hp diesel m.u.-ed behind its tender, hauling heavy freight trains on a division with a few significant hills but largely flat terrain. The steam locomotive would be doing most of the work most of the time, but at low speeds (leaving the starting point, cresting the steepest hill) the diesel (whose tractive effort is about equal to that of the 4-8-4) would be doing about half. To get the equivalent horsepower with just steam would involve something huge (a "4-10-4," perhaps, or a PRR Q-2) and still wouldn't have the same tractive effort at low speeds. A pure diesel horsepower equivalent -- a four or five unit lashup -- would have been more expensive (at 1940s prices for diesels and steam) and would have been "overkill" in terms of tractive effort.

(We're getting to the question.)

Now, in @ (the actual world, as opposed to alternative histories), at least one railroad operator noticed this. When the U.S. Army Transportation Corps was operating the Trans-Iranian Railway during the Second World War, they found that the optimal power (I think the highest tonnage rating) for their trains on one stretch was a combination of a steam locomotive with a diesel. (The diesel would have been an "RSD-1," the CC modification of the Alco RS-1. I don't know what the steam locomotives used were.) It could pull more up hill than double-headed steam, and keep the timetable with more tonnage on level sections than two diesel units! (I have always assumed that this was double-heading: two engineers. But had the practice continued in peace time -- under commercial constraints rather than in a war-time emergency, so worrying about costs -- it would have been an obvious application for steam locomotives with m.u.-ed diesels!)

So, QUESTION: in the U.S. in the 1940s and early 1950s, how many railroads REGULARLY used steam/diesel combinations on trains? Does anyone know what such combinations were like in terms of efficiency? (As in: did any railroad manager come out and say in public "the combination is better than either pure steam or pure diesel"?)

And, SECOND QUESTION: am I right in believing that equipping steam locomotives to control diesel units in m.u. was NOT done at that time, but only later?

northpit wrote:how was multiple engines controlled back in the day ? today we connect 27pnt jumpers ,were other steam locos ever remotely controlled from one location?

Part of the design of the Ross Rowland/American Coal Institute's ACE3000 proposal back in the 1980's was to allow operation of multiple units by a single 2 man crew. Of course, had these locomotives been built they would have been heavily automated, which certainly wasn't the case with "classic steam"..

The ACE project for a new, "high tech," steam locomotive around 1980 has now been mentioned a couple of times. Here's a reference, with further links:
http://www.trainweb.org/tusp/ult.html
("The Ultimate Steam Page" WWWebsite also has information on several other post-1950s steam locomotive modernization and development projects, a few of which have led to actually working locomotives. Also links to many other things that might interest a serious student of steam locomotives.)

The ACE patent papers are among the documents linked to. I haven't read them, but they might contain hints about the kinds of sensor and control equipment thought necessary to a steam locomotive as easy to operate (and as feasible to multi-operate) as standard diesels.

I believe the first steam engine that could control diesels was the Clinchfield 4-6-0 in the 1970s.

I don't know about the US, but Australia's West Coast Railway regularly ran a steam-diesel combination between 1999 and 2004. The engines involved were a restored and significantly upgraded 1950s 4-6-4 and a similar vintage GM cab unit. The different operating characteristics were seen as complementary, but I don't believe they regularly ran steam-only trains to compare.

West Coast Railway was a very interesting operation: steam (steam/diesel combination) on REGULARLY SCHEDULED passenger runs on weekends. I used to live in Melbourne (Australia), and took the West Coast train to Warnambool (west of Melbourne on the south coast of Australia: train trip of maybe ?? 4 ?? hours, so long enough for both locomotives to stretch their legs) once. (Right Whales come within a hundred yards or so of shore near Warnambool in the calving season -- September as I recall -- and whale watching is about the best reason to go to Warnambool.)

I believe that West Coast, in addition to m.u.-ing their Hudsons with A-7 (= double-ended "bulldog cabbed" EMD units: EMD's first CC design, truck design leading to the SD series), rebuilt at least one Hudson with a modernized firebox for more efficient or environmentally acceptable use of coal. Pity they went out of business. (Melbourne-Warnambool passenger service now run by V-line, the state intercity railway passenger operator, with pure diesel power.)

Re: how many diesel units assist a 4-8-4, here's MILW 261, coming out of Chicago with a BNSF employee special, at Naperville, Illinois on June 25, 2004. This is Illinois prairie country but 261 is assisted by TWO Amtrak units. Possibly they were present for backup in case of steam engine failure, or were designated to take the equipment someplace else after the trip was over, rather than to actually "assist" the fully capable 261 which certainly appeared to be pulling the load when I took the photo. Later, in September 2006, I photographed the 261 triple-heading with two Chinese QJ 2-10-2s at Bureau Junction, Illinois on the IAIS.

You can't MU locomotives to one another. You will never reach a safety factor that is high enough to satisfy FRA nowadays. It's not so much the control of the locomotives they are concerned about, it's the danger aboard. Safety precautions are taken when diesels are MU'd, however you can't implement safety precautions on a boiler. Their fires don't extinguish themselves if there is a low water condition, and there are a number of other things that can go wrong. Trained firemen are aware of the locomotive's power plant and how to troubleshoot them if there is a situation. If they aren't certain that something is working properly, they're aware of a way to check that the situation has not escalated into the danger zone yet (and they'll be able to implement a procedure to remedy the situation), or if the situation has already escalated to that point, they're aware of what needs to be done. How can this take place in a trailing steam locomotive of a double header?


Mainline steamers nowadays are equipped with MU stands and 27-pin connectors at the rear of the tender for connecting their controls to a diesel. The controls are not connected to the throttle. Instead, there is actually a control box mounted next to the engineer which is basically a dumbed down version of a control stand. By this, I mean a 9-position rotary selector switch (notch 0-8), dynamic options, et cetera. The rotary switch is for kicking the traction motors in action. I'm not sure how the dynamics are set up, but I wouldn't be surprised to see if they had a selector switch that alternated between "power" and "dynamics", and the levels were controlled VIA the control switch.

see the following image for an example of a cab control box:
http://frisco1522.org/gallery/2001breakin/jeff.jpg
Photo hotlinked from Frisco 1522's website.


Regards,
Mike Walsh