Howdy-- I’m interested in the curious history of the American freight locomotive, which led to the lowly end-cab diesel yard switcher becoming first a ‘road switcher’ with two hoods, and ultimately the ‘comfort cab’ behemoths pulling freight today, but still with front and rear platforms and still called ‘road switchers’. I don’t think you’ll find the same evolution in Europe or elsewhere.
I’m hoping to find links to books and articles discussing this history and the reasons for it, so if you know of any, I’d appreciate them.
As an aside, I also wonder at the persistence of the Norfolk & Western, and the Southern, at keeping the ‘short hoods’ of their road switchers high, and running ‘long hood forward’, into the '70s, I think. Do you know of their reasons for this practice?
Start with the Alco RS-1 on the back of a napkin (stretched S-1) and it’s cousin the EMD NW-5, find a copy of all of Kalmbach’s Diesel Spotters Guides and exhume an article in trains about the pre-WW2 evolution of the RS-1/RSD-1’s that went to Iran. (the US Army took the first 13 RS-1s built in 1941 for the Rock Island, Milwaukee Road, New York, Susquehanna & Western, Atlanta & St. Andrews Bay, and the Tennessee Coal, Iron & Railroad.)
OK, Mr. Lynn:[You stated and asked] “…Howdy-- I’m interested in the curious history of the American freight locomotive, which led to the lowly end-cab diesel yard switcher becoming first a ‘road switcher’ with two hoods…”
Might as well start with the Buckwalter ‘Electrics’ They were orginally (1912) built as battery powered electrics and later converted to gasoline power. They were well-used in the big cities of the N.E. see @ http://prr.railfan.net/photos/StreetTractors/PRR_14380_3-8000_side_EE6573.jpgTHwnthere was the Baldwin Locomotive Co.'s Road (actually called a Transfer- Switcher) (Center Cab) DT6-6-2000 built in the late 1950sinto 60’s. They lasted until scrapped in the 1970s. see @ http://www.railpictures.net/photo/415423/
Baldwin also built ‘End-Cab’ switchers starting in 1939 with their
It started out with the Alco RS1, as has been mentioned. Railroads were still in a steam locomotive buying mentality and had been using downgraded locomotives such as 2-8-0s, 4-6-0s, 2-6-0s and the odd 2-6-2 in both yard and local service. There was no diesel equivilent until the railroads asked for the RS1.
Cab units were ordered as sets that railroads expected not to break up, the whole set being considered one locomotive (steam mentality again), with the FTs being drawbar-connected. As they generally lacked footboards (and sight lines for that position) and any sort of rear visibility, they were terrible for doing anything other than leading on the road. Furthermore, the truss-style construction meant that it was very difficult to access the machinery when something went wrong, short of pulling the prime mover out through the roof.
The RS1’s sales took off, and others took notice. Alco bumped up the horsepower in the RS2 to make it equivilent to the current road locomotives. EMD tried to counter it with the BL2, which was the worst of both worlds, before finally producing the GP7. This model of course took off as it could be at home anywhere doing anything (if it had a steam generator) and was far easier to maintain.
The next evolution was the short hood, created for visibility. As for why N&W and SOU stuck with the high short hood for so long has been explained in a variety of ways, none of which have been conclusively proven. They include protecting the engine crew, enhancing bidirectional capability as the short hood was in reverse so sight lines were less impacted than when running long hood forward in the traditional setup, and convincing the crew that LHF operation was equivilent to SHF operation. Meanwhile, units got larger, stronger, and more reliable.
The first wide-nose safety cab emerged on CN in 1973, providing more comfortable space with added collision protection, though at a price premium. Other railroads began to pick up the design in the late 1980s, a
The wide short hood were developed for a couple reasons. One was the increased use of cab electronics and the need for some level of climate control. You really don’t want to bake or freeze the electronics if you don’t have to.
Also, the need for space to better organize the cab electronics and to create a better toilet compartment played a roll. The short hood used to house all sorts of stuff, from the toilet to the sand box magnet valves to the cab signal equipment. It was a mess. A lousy environment for the equipment and hard space to maintain. The equipment rack in the new cabs and separate toilet compartment “across the hall” are a big step up for everyone.
On top of that, there was a push to make the cab compartment quieter, better ergonomically and to conform to new collision standards. The nose door overlaps the nose which makes for much better conditions when colliding with a tank truck, for example. The nose door plus interior door make for a much quieter environment. Although the desktop controls were botched, in general, the work position and provision for integrated displays makes for a simpler design and better ergonomics.
The idea of a hood unit on road trucks started before the RS-1. Preston Cook claims that the NW3 first produced by EMC in 1939 was the first road switcher. It didn’t have the short hood, but it did come equipped with road trucks and a steam generator.
I think the idea of sets of units as “one articulated locomotive” was more a marketing convention than a steam-oriented operating mentality. What was far, far more important was the pending litigation by the unions that each MU-capable independent ‘unit’ in a diesel consist would count as a locomotive for employment purposes – a situation that if I recall correctly wasn’t resolved until the late '40s. The only ‘sure’ way to get around this would be to have ‘units’ either semipermanently coupled together or clearly numbered as parts of a single locomotive.
I think it’s no coincidence that as soon as this issue had been worked through, railroads generally got rid of drawbar connections between units or “904-A,B,C,D” style numbering conventions… but not before.
I think the history of the Santa Fe FT units makes the point very clearly.
Santa Fe never used drawbars and some references suggest these units were type FS (Fourteen Hundred Horsepower Single Unit, rather than Fourteen Hundred Horsepower Twin Unit). This had an unexpected advantage. Santa Fe unions wanted a crew in every cab. I haven’t checked this but I think only sets 100 and 101 were built with two A units initally, and one of these was soon replaced by a third B unit, so each locomotive had only one cab. I think most of the Santa Fe FTs were built a
NorthWest
Cab units were ordered as sets that railroads expected not to break up, the whole set being considered one locomotive (steam mentality again), with the FTs being drawbar-connected.
I think the idea of sets of units as “one articulated locomotive” was more a marketing convention than a steam-oriented operating mentality. What was far, far more important was the pending litigation by the unions that each MU-capable independent ‘unit’ in a diesel consist would count as a locomotive for employment purposes – a situation that if I recall correctly wasn’t resolved until the late '40s. The only ‘sure’ way to get around this would be to have ‘units’ either semipermanently coupled together or clearly numbered as parts of a single locomotive.
I think it’s no coincidence that as soon as this issue had been worked through, railroads generally got rid of drawbar connections between units or “904-A,B,C,D” style numbering conventions… but not before.
I think the history of the Santa Fe FT units makes the point very clearly.
Santa Fe never used drawbars and some references suggest these units were type FS (Fourteen Hundred Horsepower Single Unit, rather than Fourteen Hundred Horsepower Twin Unit). This had an unexpected advantage. Santa Fe unions wanted a c
I think it depends on the road… Some, like the Santa Fe, quickly understood the advantages of diesel flexibility. Others, such as Soo line, continued to purchase locomotives without MU well into the 1950s for specific jobs. One of the interesting things is how long it took for EMD to include nose MU receptacles as an option on F units.
I suppose I shouldn’t have omitted these as they are steps in the road switcher evolution, however few in quantity. I suppose we could add in the two NW4s which were hood units with road trucks, though recycled rather than for a specific use. I don’t think Mopac ever used them in road service. The NW3s did see some branchline service but ended up in yards, interestingly on the Clinchfield in the case of one unit.
The WPB didn’t really get going until 1942 so I don’t think that the TRs were built the way they were for that reason. I suspect IC wanted something similar to its earlier T, and EMD simply repackaged the FT into the NW3 carbody. IC didn’t buy any FTs, interestingly enough.
I didn’t mean to imply that the WPB influenced the design of the TR 1, which was clearly pre WWII. However, WPB restrictions in 1942 and later would have prevented EMD from offering these to other customers in competition with the RS 1, for example or as an alternative to the FT.
I think there are some other aspects of the ‘evolution’ of modern road units that exceed just the origins of typical road-switcher configuration.
The BL2 considerably postdates most of the locomotives discussed, but lacks many of the ‘typical advantages’ of the evolved road-switcher configuration, notably access to a platform at the front end or usable walkways from the cab directly to a rear platform. It’s like an ugly F unit with (somewhat) better visibility to the rear and different frame bracing, with style trumping utility. We all know what came of that, but it might pay to remember what Dilworth said at the time about the Geep development. And that is the locomotive that essentially defined “normal” road-locomotive configuration right up to the time of the wide-cab revolution we were discussing earlier.
There were other attempts at evolutionary lines. One was the H20-44, which I’m surprised hasn’t been discussed so far in this context. One of the discussions in Kiefer’s 1947 motive-power report is the advantage of ‘shorter’ locomotives of given DBHP - you can fit more train in a siding, and there’s normally less weight and cost. So it isn’t really surprising to see FM make the attempt to sell a road locomotive in an end-cab switcher size. In an era when long-hood-forward was typical (analogy with steam practice; keeping the mass of the engine and machinery as a ‘buffer’ against collision; etc.) this was not as unsafe as the sitting-in-a-Boston-rocker-across-grade-crossing terror that an end-cab road locomotive would otherwise present … and which many cab-car engineers no doubt rue today. I am tempted, somewhat, to see an extension of this in the late EMD ‘switchers’ with toilets in the hood waist and Flexicoil road trucks (cf. those on the LIRR)
Someone (Peter Clark, perhaps) can do a better discussion of the excursions into cowl units, and the reasons theref
Sorry for my slow response. There is a lot to digest in these terrific responses, and a many more factors to consider in the history than I had anticipated. For instance, I had not really considered the EMD NW3/5 models as precursors to the road switchers, or as (attempted) competition with the RS-1. But now I notice that Louis Marre does say, in his Diesel Locomotives: The first 50 Years, that “The NW3 and NW5 were marketed as passenger terminal switchers, in competition with Alco’s boiler-equipped RS-1” (p. 25).
Aside: There is an NW3 on display at one of the stops of The Empire Builder on the Great Northern route–I have a photograph of it. There were only seven made, all for GN, and only 13 NW5s, the latter after the war; not much competition for the RS-1, which was going great guns by that time.
Then there were the various center-cab terminal units, and GEs center-cab xx-ton switchers (even off-center cabs which look like later road switchers: see Marre, p. 188), which leads one to create diagrams like biological-evolution clades, with offshoots and dead-ends here and there.
Then there are the factors that went into road-worthiness, i.e. road trucks, steam boilers (for passenger operations), union rules, toilets, and railroad demand. Still, when you think about it, it’s interesting that the design of road diesel-electrics initially leapfrogged the road-switcher evolution altogether. EMD’s cab units were, I would venture say, just streamlined (after the art-nouveau fashion of the '30s–viz. the Air-Flow autos from Chrysler) versions of the utilitarian box-cab locomotives, but quickly took over directly from road steam (interrupted by WWII). As pointed out above, they were really useless for switching and even branch-line service (where switching was required), with B units even more limited. It looks like it was really the RS-1 that bridged the gap between diesels for yard work and road work.
Much depends on the type of control stand. I’ve never run one, but I’ve read that trying to run long hood forward on a unit with “desktop” controls is a real pain.
At least the long hood is narrow, like all road switchers. Running long hood forward with a cowl is a problem. Switching with a cowl with a “Draper taper” would be only slightly less so.
Of course, once you put several units together, backing up is a problem anyhow. You begin to appreciate what it took to direct a switching movement in the days before radios…
I recall an image in Trains of the Santa Fe doing switching on a local with no fewer than 4 F’s, A-B-B-A.
The BL2 wasn’t very good at anything.
It was basically an F unit with some corners cut off for visibility.
Access to the prime mover must have been really terrible.
But what had in its favour was that it could be built using most of the standard components that went into an F unit, the electrical cabinet, the radiators and cooling fans, the cab layout would have been much the same with a few more windows.
It could be built on an F unit production line.
Look at the GP7. It reverted to the radiator layout of the FT, admittedly with AC fans, which were a big help, but two separate radiators fore and aft of the engine. So the cooling system was different from the F unit. The electrical system was quite different, with fewer components to keep the price down so railroads could buy GPs for secondary duties but keep buying F units for the main line. That didn’t work…
The GP7 and GP 9, and the matching SDs were a success and the F units went away. But as soon as the space was available, the radiators on the SDs moved back behind the engine in a single group, and from the GP30, they were behind the engine on GPs as well.
The BL2 was a half hearted attempt by people who wanted to build basically one type of road locomotive, but whose
Come to think of it, I’ve got a video of a quartet of GP40-2s humping freight cars in a small yard here in Framingham, MA. Couldn’t have been easy to see all the way down that line, but they did have radios. Here’s a still:
You don’t want those behemoths in your yards, backtracks or branches because they are too heavy, don’t turn worth a crap and have limited drawbar/coupler throw (especially the GE’s and EMD’s aren’t that much of an improvement.). The wide cab takes a backseat to those issues.
Yards, backtracks and branches were designed and built in the days of the 40 foot boxcars, no rail anchors, less than 90# rail, switch engines with no pony trucks or end cab switchers. Present that type of track and design to a railroad for a new industry or yard track, much less branch main track, and you will get laughed out of the room.
