Discussion in 'HO Scale Model Trains' started by cjfeltner, Dec 22, 2006.
what is a switcher engine? why is it called that?thanks
That is a locomotive used to switch cars in a yard.
A switcher is a lower-horsepower locomotive that does smaller jobs. Moving cars in a yard. taking care of the cars from a passenger train before and after the train runs. Sometimes taking a amall train on a short slow trip.
)If you watch the show, Thomas, Toby, Duck are all switchers).
Then there is the road switcher, which I'm not sure of a definition for.
Switcher = lightweight, low-horsepower (around or under 1000hp) locomotive with small fuel tank and low-speed trucks, primarily used for shunting cars in a yard or making local deliveries to industrial spurs. These include the Alco S-series, EMD SW and NW series, GE 44- and 70-tonners, etc.
Road switcher = medium weight, medium horsepower locomotive with larger fuel tank and trucks capable of mainline road speeds, mostly used for local trains delivering cars to industries along a rail line, but can be used in a pinch for helping haul mainline trains. These include locomotives like the 2000hp EMD GP38-2, GE B23-7, etc.
Road freight locomotive = heavyweight, high-horsepower locomotive with very large fuel tanks for long range running, usually with a turbocharger and trucks geared for fast running, majority of which has 6 axles. These include locomotives like the 3000hp EMD SD40-2, 4400hp GE AC4400CW, etc.
Passenger locomotive = heavyweight, high-horsepower locomotive with very large fuel tanks for long range running, usually with a turbocharger and trucks geared for VERY high speeds, majority of which has 4 axles. These include locomotives like the 3000hp EMD F40PH, 3200hp GE P32AC-DM Genesis, etc.
Hope this helps.
Those are modern. If you're modelling an earlier era, some general axioms will be different. For example, most passenger engines used to be 6-axle.
Also, nowadays, you can find engines up to SD40-2s in common use as switchers. Older road freight engines often end up downgraded this way.
I don't know if the term 'road switcher' is actually in normal use by the railroads anymore. It was used in the steam-diesel transition era, when road freight engines weren't much bigger than switchers. The term distinguished hood units from streamlined cab units, which could be for freight or passenger.
Depends on what prototype railroad you model. I model Santa Fe, they seldom bought switch engines. In the days of steam, they would take older 2-8-0 consolidation type locomotives and remove the leading truck to make 0-8-0 switchers. When they first converted to diesel inthe 1940's, they bought Alco S1-4s, Emd Sw's, etc; but virtually all of their switch engines used from about 1960 on were downgraded older road units. Here in So Cal if you go by a BNSF yard and observe the switch engines at work, you will see old downgraded gp7s & 9s, gp30s, & gp35's doing yard service. At the main classification yard in Barstow, BNSF and Santa Fe before them use a sd24 or 35 with one of the old Alco Alligators that has been converted into a slug to do the switching.
Yes, modern switchers can be up to SD-40-2's!!! Smaller switchers are generally geared lower, so that they can move long trains around, with less horsepower. Many don't go very fast though, but thats fine, as it is dangerous to go fast in a yard. Switchers are only in the the americas, they have shunters in the UK, which are essentially the same thing with a dfferent name.
A note about the SD40-2s being used in yard switcher service..
Technically, those aren't really SD40-2s anymore. The ones UP converted for use in yard switching for example have been de-turbo'ed. Consequently, their HP output has been dropped down to 2000hp, which effectively makes them SD38-2s (i.e. an overgrown GP38-2). Yard switchers are usually low-horsepower because they don't need to run at full road speeds, which is another reason why yard switchers are rarely turbocharged-- A turbocharged loco doing yard duty is very fuel-inefficient.
The SD38-2s built as new from EMD were almost exactly the same-- Same engine, no turbocharger, but has a radiator section with just two radiator fans (that's how you can tell the difference between a de-turboed SD40-2 vs. a straight SD38-2). They were designed for slow hauls, such as coal/iron ore drags or for pushing strings of cars up a hump in a hump yard. The SD38-2 is basically an overgrown GP38-2 road switcher-- Same engine, just different chassis to accomodate the 3-axle HTC trucks.
I don't know if UP changed the gearing on the de-turboed SD40-2s though.
Well, here in the Shreveport/Bossier City area SW1500's were used to pull a string of about 30-35 loaded gon's across town and deliver them to a concrete plant. I've mostly seen only two of them on this run for many years and on occasion they would run GP30 or 38's to do the service but now it's mostly just GP's that do the service now. Once I did see and couple of SD40-2's doing it but just the one time. I've also watched KCS run a 4 axle GP series locomotive with a safety cab for the run a few times. I don't think they have been a couple of these.
Now that this subject has been brought up was there ever an SW series locomotive built or rebuilt with 3 axle trucks? With that in mind I feel a kit bash coming on!
A quick thumb throught the Diesel Spotter's Guide (1966) doesn't reveal any 6 wheel trucks under switchers. I suspect that the extra length would have reduced flexibility.
There was the "light road switcher" GMD1, that came in both B-B and A1A-A1A versions. CNR used to transfer them around and switch the trucks (and the numbers).
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