Dick Dilworth and the EMD GP7

(Return to the Locomotive Notes Index Page)

(from The Dilworth Story, by Franklin M. Reck, Copyright 1954 by Electro-Motive Division, General Motors Corporation, pages 94-99)

The Geep

(Editor's note: The slang term for the GP locomotive is shown here as "Geep", rather than "Jeep", as used in the original 1954 book. ds)

A friend of Dilworth's has said that Dilworth seldom goes around a railroad terminal for fear the Diesel locomotives idling there will leave the track to jump on Dick and paw him and lick his face. This is a way of saying that, if a locomotive were animate, it would show the same affection toward its design chief as a dog would show toward a wise and sympathetic trainer. Certainly this is true of the foreign and military locomotives, but these were merely curtain raisers to his creation of what was to become Electro-Motive's most recent best seller, the General Purpose, or Geep, the final major chore of almost a half century of productive engineering.

The GP came into being because of a postwar demand for a locomotive with characteristics not quite met by any existing EMD model. The railroads wanted a handy all-round unit, simpler and less expensive than the regular passenger and freight locomotives. Such an engine would be able to drop a train on the main line, do some work on a sidetrack, go back and pick up the train, and get it in the clear to carry out a meet order. It would be able to handle way work around a station, which meant that it would have to go easily in both directions, without inconvenience to the man in the cab. It might be hooked onto a work train or a wreck train. Though EMD had developed freight, passenger, and specialized locomotives that could do most of the work of the railroads, none of them could economically meet all these demands.

Since the regular engineering department was already overloaded with the multiple tasks of modifying existing models, the task of developing a general-purpose locomotive fell to Advanced Engineering [a new department at EMD, created especially for Dilworth to relieve him of the routine engineering work that had become mundane for him after a 40-year career]. Dilworth welcomed the assignment because be felt that it represented EMD's golden opportunity to complete the Dieselization of American railroads.

As be saw it, the 30,000 miles of main line were already Dieselized. These miles carried half the ton-miles of all the freight movement of the country, and here the conquest was complete. At the other end of the scale, the 70,000 miles of branch line were partly Dieselized, but they carried only 2 per cent of the freight and didn't count for much. The big opportunity for locomotive sales was on the 130,000 miles of secondary line that carried the other half of the freight tonnage.

Dilworth knew that the railroads traditionally bought locomotives for their main lines, then downgraded them to secondary and branch as they grew old and obsolete. EMD had already attempted to combat this habit by turning out a branch-line locomotive, but this model had some of the appearance of the regular main-line models; so it too found its way onto the main line. This didn't discourage Dilworth.

"In planning the GP," he says, "I had two dreams. The first was to make a locomotive so ugly in appearance that no railroad would want it on the main line or anywhere near headquarters, but would keep it out as far as possible in the back country, where it could do really useful work. My second dream was to make it so simple in construction and so devoid of Christmas-tree ornaments and other whimsy that the price would be materially below our standard main-line freight locomotives."

To achieve these twin dreams, Dilworth used the standard freight unit of 1,500 horsepower and gave it a body something like a switch engine. He gave it all the necessary machinery so that it would function as well as a main-line freight locomotive, but he didn't bother about appearance at all. Look at it today, and you see that the bluntly rounded nose is gone. There is no sleek portholed car body hiding the machinery. The housing of the machinery stands out in the open, stark and businesslike and may be reached by a catwalk on either side, like a switch engine.

Because he hoped that his unlovely creature would find its way onto secondary lines, he introduced what he calls a trick of control by which the engineer feels an instant response the moment he opens the throttle. This was different from mainline locomotives in which there was no response until the generator had poured enough power into the traction motors to start them turning. Getting an instant response wasn't important or even advisable on the main line where trains were a hundred or more cars long, but it would be useful on the secondary where trains were shorter and where the locomotive bad to do a variety of jobs. But chiefly it was useful because it gave the engineer confidence. He knew that the engine was going to go to work for him, right now.

"When he opened the throttle," Dilworth says, "I wanted him to feel it in the seat of his pants."

This and other innovations made the GP a unique locomotive, but it was the location and arrangement of the cab that won the hearts of the railroads as much as any one thing. Dilworth didn't put engineer and fireman in front, as in the mainline models. He placed them about two-thirds of the way back, with some of the machinery in front and some behind. Thus, whichever way the engineer was running it, he was looking out past a nose, as he had always done in steam.

Then Dilworth had another bright idea. Before settling on the arrangement of the cab he built a wooden mockup, windows and all, and invited engineers from the railroads to sit in it and tell him where to put controls, seats, armrests, and other devices that affected the operator.

The arrangement adopted as the result of this cooperative effort, plus some timely suggestions by Jimmy Hilton, permitted the engineer to run the locomotive equally well in either direction without having to move to another operating station on the other side of the cab. Whichever way he was going, he could conveniently handle the controls, look out the window, and see the signals.

This locomotive, the GP, went from Advanced Engineering to the regular engineering department, underwent the necessary modifications, was offered to the railroads and put into production. It was a hit from the start.

Certain intangibles had much to do with its popularity. Aside from the fact that it cost less, here was a locomotive that looked like an old and half-forgotten friend. After some years of living inside the strange and wonderful efficiency of the streamlined Diesel, old-timers found it a comfort to return to something rememberable. It was like old home week to get into the cab of the GP. It was a locomotive cab. There was a front end, whichever way you looked. You were no longer perched in front and atop several thousand pulsating horses, you were behind them.

"It was a tool," says Hilton, "that fitted the railroad man's hand."

Actually, it was basically the regular freight unit that EMD had been making for over ten years, stripped down to its functional parts. Yet railroads everywhere echoed the sentiment of one assistant superintendent of motive power who told Jimmy Hilton: "There isn't anything that locomotive won't do or can't do any time of the day or night."

It was ugly all right. Ugly, unpretentious, and businesslike. And it became the modern best seller in the EMD line.

Yet it proved to be Dilworth's greatest disappointment. He had hoped it would be the key that would unlock the door to the secondary lines. Instead, like all other new locomotives, it was bought principally for the main line, there to serve until the day when newer and shinier descendants would relegate it to the service for which it had been originally planned.

Aside from the planning of the GP, Dilworth's Advanced Engineering Department laid out rough plans for foreign locomotives, using as many standard American parts as possible. Locomotives intended for Israeli, the Scandinavian countries, Newfoundland, and Brazil were started in Advanced Engineering and carried to completion elsewhere. The department was also given the job of initiating foreign engineers into the mysteries of Diesel-electric operation.

Early in 1950 Dilworth retired from Electro-Motive and for the next two years served the division as independent consultant. In 1952 he took home his slide rules for good, leaving to others the job of laying out and improving the locomotives that will soon complete the Dieselization of the railroads.

(See also: "The Beloved Geep", by Max Ephriam, Jr., in Trains magazine, Volume 55, Number 4, June 1995, pages 44-47.)