Beauty of Current Diesel Locomotive Cabs Background of Designs?

Question

What are some origins to the beautiful, current cabs of diesel locomotives on the rails today?

Answer 1

There appearance today is largely because of the safety and crew comfort innovations over the past few years.  But the story started decades ago.

The first steam engines had no cabs.  One would think that would have been an early on revelation, but the first cabs, as we understand them today, didn't come along until 1849, a full 18 years after the first locomotive steamed up.  There were add on "awnig" type experimental affairs, but these were open to the front and provided little protection from the elements.  By 1851, most locomotives being built were built with cabs.

There were experiments with cab location over the years, most notably the "camel backs."  These engines kept the fireman at the rear of the boiler (with a hood for protection) while the operating cab was moved to the center of the engine, usually right behind the steam dome, where the throttle mechanisms introduce live steam into the journey to the cylinders and out the stack as expanded steam.

In the diesel era GE used the "center cab" for their switch engines of the 50 and 70 ton variety.

Though most of the electrics and diesel electrics have had their cab near the front of the locomotive, the concept was born in the age of steam.

The Southern Pacific was the only major US railroad to run steam engines with the "cab forward."  The name stuck.  These were born of necessity as trains that had to battle gravity to the Donner Pass summit at Norden did so for many miles in wooden snowsheds and tunnels.  The engines' exhaust was extremely uncomfortable and dangerous in the least, and could be lethal for crews operating conventional engines through these areas.  So, the crew was moved to the front by running the engine "backwards" as a part of its design.  There were other advantages for the crews as well.

It involved much more than just running the engine backwards.  Were this true, then the engineer and fireman would be on the wrong side of the cab, respectively.  So, it took a totally new design that was conceived by and built by the Baldwin Locomotive Works.  Their efforts earned them and the locomotives SAE engineering awards on more than one occasion.

Visibilty was improved immeasurably by riding up front, with no long boiler in front of you, having to hang your head out the window to see.  Though many railroads of the northern lattitudes, such as the Great Northern, did operate some of its larger steam engines with "vestibule" cabs, that were enclosed to a great degree, making them much more comfortable to work on in winter months.  But most of the conventional steamers had a canvas curtain on a rod behind the cab for protection, and that was it.

So when the diesels came along, the decision to place the cab up front was an easy one to make.  The early offerings by EMD, the FTs, F3s and F7s and the Alco PAs used what we call "wide bodies" today, though functionally, there were few similarities.  The cabs to these engines could be accessed through the nose, but the main access was from the doors at the top of the side ladders.  In addition, the cowlings ran the length of the engine, called "car body" style, or "covered wagons" in the vernacular.

The true "wide bodies" of today have been around for quite awhile, actually, being optional equipment of the first EMD SD-60s.  Coming in the door, there is a toilet facility immediately available.  This was a great new feature, as the old facilities required an uncomfortable squeeze through a small door in the nose of the engine.

Another feature I like is the second door to the cab that one goes through to access the cab.  This really cut down on the unpleasantness experienced by the guy sitting on the left hand side when the weather stripping was long gone on the door to the outside right in front of his seat.

Changing ingress allowed for the more smooth appearance.  It also allowed for raising the level of the cab floor.  This too is a safety improvement, but I think the improvement was just a legacy.  The floor is higher for practical engineering reasons needed in the locomotives design.

The cabs are also more crash worthy than older styles as well, with substantial uprights for more overall strength, and the second door may come in handy keeping debris or liquids from a train - truck collision from entering the cab.  The overall distance between the front of the cab and the front of the locomotive has increased as well, when compared to many different cab stylings of earlier engines.  Primary in this category is any number of the old GE "U-Boats" where there was zip between you and the front of the engine.  Their "nose" was more like a pig's "snout."

The final contributing factor to the present day aesthetics of the locomotive cab includes efforts to increase visibilty yet still provide for better protection for the crew within from vandals' projectiles, beer bottles, rocks and concrete, primarily, but there is the occasional cinder block or bowling ball.

With the improvement to cab interior including "desk top" controls, the crew sits even further back from the front of the locomotive.

Heating and AC are much better utilizing duct works these days, so the big "ice cream freezer" that one time occupied the roof of a locomotive has further smoothed the lines.

A couple more changes, and the stylings of the old F7s may re-appear.  Those were good looking engines, no matter what the livery they were painted in.

Even yellow and gray with red pinstriping.  Blaaah!