All these engine types and models are driving me 'loco' !

[sully57]

It's become apparent to me that I need a course in locomotives, all eras all types. I am to the point where I am purchasing locomotives for my work-in-progress layout. And when I make a purchase, it is rather blind. I have been bitten by the DCC sound bug, and will probably never purchase a locomotive again without it. Although they are prohibitively expensive. But I don't know the difference between a GP35, or 40, or an SD etc. etc. Not 100% certain what the roles of switchers are. I know certain locos were made to perform certain tasks, and I really would like to understand what locos (steam AND diesel) perform what tasks, in an operation. I have purchased a lot of instructional rags from MR, as well subscribe to their monthly MR Magazine. But I need some concentrated, understandable instructional info on locomotives. Slick color photos are always welcome as well! Thanks, in advance, for any reading suggestions anyone might have (or videos). -Sully

[Jetrock]

Here's a link to Kalmbach's field guide to modern diesel locomotives:

http://store.yahoo.net/kalmbachcatalog/01113.html

Another one on early diesels:

http://store.yahoo.net/kalmbachcatalog/01054.html

And one on steam:

http://store.yahoo.net/kalmbachcatalog/01051.html

This is a rather involved subject, one that will take time for you to learn and identify, especially if you are new to the hobby. It helps if you have some idea of what kind of railroading you want to model--what era? what line? what part of the country? what kind of operation?

Switchers are intended to move small numbers of cars around at lower speed--in yards, or at industries, or any place where trains are broken down and put together. They are smaller, lighter and slower than road engines, but are less expensive, easier to maintain, and cheaper to feed. Often older, lighter locomotives are demoted to switcher service after newer and more powerful locomotives are purchased, but sometimes short lines will use small 'switcher' equipment to pull mainline trains because they don't carry as much traffic, go as fast, or have enough money to afford shiny new engines.

GP-35/40/etcetera: Geeps are "road switchers"--heavy enough to be used in mainline service but handy enough for switching chores, GP stands for General Purpose and they were used everywhere for everything since their introduction in the 1950s. SD's (Special Duty) are similar, from the same manufacturers, but have six-wheel trucks instead of the four-wheel trucks that GP units have--I think for more traction and lower ground pressure.

Steam engines: Steam engines are generally intended for either freight or passenger use. Passenger engines tend to have a smaller number of driver wheels (the big wheels that are supplied power from the steam cylinders) and those wheels have larger radius--the larger the wheel radius, the faster the locomotive's top speed. Passenger locomotives also tend to have pilot and/or trailer wheels (the little unpowered wheels in front or in back of the steamer), which help stability in high-speed motion. The most common type of American passenger locomotive in the 19th Century was the 4-4-0, known as the "American" ("4-4-0" refers to four pilot wheels, four drivers, and no trailers.)

Freight steam engines tend to have a larger number of driver wheels, of smaller radius--regardless of a driver's size, the actual area that comes into contact with the rail is about the size of a quarter. More wheels = more traction. Freight is heavy, while passengers are light--so freight engines need a lot more traction. Smaller wheels also helped low-end performance--steam switchers tended to have the smallest wheels, since they weren't intended to go fast, and often had no pilot or trailer wheels at all. Common 19th Century freight locomotives were the Mogul (2-6-0) and Consolidation (2-8-0.)

This is literally *just* scratching the surface of the subject--a couple good reference books can help. Stop by your local library and look for the section on trains, rather than model railroads, so you can browse at some references before having to buy 'em.

[hubbabubba2]

Hi.
Some more info:

GE locomotives: Those with the prefix B has four-wheel trucks and are used in the same way as the GP: s. In the same way those with the prefix C has six-wheel trucks and correspond to the SD: s.

ALCO use a 4 as the first digit for their four-wheel trucks locomotives, and a 6 as the first digit for their six-wheel trucks locomotives.

Generally speaking locomotives that were built at a later date have a name with a higher number. For example GP9: s were built 1954-1959 and GP35: s were built 1963-1966.

Also it’s a good idea to do some reading about the railroad you try to recreate and chose a time and place. Because different railroads has chosen different locos for their needs and might as well have used them differently trough out the years.

Mattias

[Virginian]

Steam locomotives were specialized machines, and there were a lot of different types used to handle the needs. Each railroad had a motive power dept., and they had their own philosophies. If you look at what the different roads ran you will soon see what I mean.
N&W was fairly unique, and they tried to keep things simple. The largest non-articulated freight loco they had was a 4-8-0. But they fielded two articulateds to handle everything freight wise on the mainline, the 2-8-8-2 Class Ys and the 2-6-6-4 Class As.
Their top of the line passenger steam was the Class J 4-8-4, which had more tractive effort than any other 4 coupled locomotive anybody had, freight or passenger, and easily clocked 90 plus on the flatlands. Their secondary main passenger power were 4-8-2s.
They also had several lines with load limits, and they ran 4-6-2s and 4-8-0s and even 2-6-6-2s on those.
Until they modernized the line, they also had an electric section to keep the crews from getting smothered in the Elkhorn tunnel.
They had a large fleet of 0-8-0 switchers, but they also used 4-8-0s, 2-6-6-2s, and even 2-8-8-2s for switching where it suited them.
That's just an example, but my point is to suggest that you study what some of your favorite roads did if you want to be prototypically correct. If you don't care about that or just want to freelance you can pretty much do whatever you want and not really be incorrect, because someone probably did whatever you're doing. If you are primarily going more modern than say 1955 or so, you can run just about anything as an excursion loco and be quite correct.

[Anonymous]

Another way that I remember, B is the second letter of the alphabet, two axle, C is the third, three axle.

[dehusman]

All engines, steam or deisel serve several basic purposes.

Switchers work in yards and industrial areas. They classify cars (sort by block or destination), spot and pull industries.

There are local engines that are designed to run a train over the road, but still be able to switch industries.

Road freight engines are designed to pull trains from point A to point B with minimal switching enroute.

Passenger engines are designed with higher gearing to run faster with lighter trains.

Various types overlap. 0-6-0 and 0-8-0 steam engines were designed as switchers but were often used as local engines. The first hood road diesels (those with a walkway on both sides of the engine, such as the GP7 and RS3) were specifically designed to be able to do everything. They could switch, they could run a local, they could pull a freight train and they could run a passenger train, all with equal ability. Well almost equal, to haul a passenger train in winter they required a steam generator.

Also as engines age, they get down graded to lower service. SD40-2's and SD60's were the premier freight engines of the 1980's. They are now pull the lower priority trains and are not the first line engines anymore, being replaced with C44-9's and SD70's.

Switcher steam engines tend to have no pilot or trailing trucks (0-4-0, 0-6-0, 0-8-0) and deisel switchers have switcher trucks and end cabs. The diesels tend to be 1500 hp or less.

In steam engines, the 2-6-0 and 4-4-0 were the early engines that did everything. By the 1900's the local engines were the 2-6-0, 4-6-0, 2-8-0, 2-6-2 types and the road engines were the 2-8-2 types. By WW2 the maid of all work was the 2-8-0 with road power being 2-8-2, 4-8-2, 4-8-4, 2-8-4, 2-10-4 types. There were also heavy freight engines, 2-10-0, 2-10-2, 2-8-8-2 that were designed for lugging trains. The articulated engines with 4 wheel pilot trucks tended to be for faster freight trains in more rugged territory, so 4-6-6-4, and 4-8-8-4 types were used.

In diesels, the general rule of thumb is the higher the horsepower (compared to its peers), the more likely it was used on road freight. So in 1955, when the average engine was 1500 hp, a 200 hp engine would be a real puller. In 1965 when the average engine was 2000 hp plus a 1500 hp engine would be more likely a local/switch/drag freight engine and a 2500 hp engine would be a fast freight engine. In 2005 when the average localmotive is about 4000 hp, a 3600 hp engine is the lower priority freight and the 4400 hp engine is the higher priority freight. This is all very general since engine assignments are all over the map and there is an exception to everything. If you are ing 1968 and you have a GP35 on a fast freight, it will look right. If you are ing 1975, that GP35 will probably be on a local or a less priority freight train.

Dave H.

[selector]

I am interested in this, and really appreciate both the question and the various responses. Thanks, fellas.

[dinwitty]

about steam switchers, usually no lead or trailing wheels, the idea is to get all the weight on the drivers for traction. Leading and traing wheels help guide the loco thru curves, but take some traction away from the powered wheels.
Steam switchers varied from small 0-4-0 to 0-6-0, 0-8-0, 0-10-0.
Largest would be the 0-10-2 the DM&IR had.
Some roads de-mainlined some steamers such as turning a 2-8-2 into an 0-8-2.
Although not generally recognized as a real wheel arrangement built like such, mods were done like that.

As for getting all the traction effort you can out of a steamer, the Virginian Triplex,
was a 2-8-8-8-4, essientially a 2-8-8-0 with 8 drive wheels under the tender.
The rear trailing truck had booster engines for more tractive effort.
Trailing truck boosters and tender booster trucks were sometimes done on other engines to get more tractive effort.

Diesel locos like the GP series as mentioned are general purpose, switching and road use.
F unit diesels handled Passengers but made their way to freight use as well.
The large DD40 diesel had 8 wheel trucks, and used mainly for road service, not switching.

SW locos you would find doing switching duties as well as any of the smaller diesel locos.

[sully57]

I wi***o thank everyone. Some very informative explanations here. Just reading these comments has given me much more understanding about locos in general. And Jetrock, ty for the links. I have read over the synopsis' of the early diesel, and steam catalogs (Kalmbach), and will probably pick them both up. Thanks again to all!

[trolleyboy]

One other tip you may want to think of,is which railroad aare you modelling.You can usually get decent books on your target railroad be it NYC Santa FE etc.Having a couple of books handy on what line you are modelling will help you see what type of loco's they had and for which era. This may make your purchasing choices easier. morning sun books is a good start point. Rob