The "Baby U Boat" offered a compact power house for branch line freight.

Prototype History

Builder: General Electric Transportation Systems(GE)
AAR Type: B-B
Dates Built: 1973-1976
Number Built: 163
Horsepower: 1,800
Engine: GE 7-FDL-8
Length: 54ft 8in

General Electric made history when it introduced its new "Universal" series of locomotives with the U25B in 1959. The locomotives were marketed to handle a variety of assignments and were strong competition for the more established locomotive builders.


By the time the U18B came to market in 1973, competitor ALCo had already ended American locomotive production. Indeed the U series itself was nearing the end of its run, with the Dash 7 line arriving in 1976.

Also quite contrary to its "universal" designation, the U18B was designed with a very specific role in mind. Using only an 8 cylinder version of the 7-FDL engine, the only North American production GE locomotive to do so, the U18B was marketed for light duty use on local freights and branch lines.

Since the U series had already been dubbed "U Boats" it only made sense for these shortened versions to be called "Baby Boats." Aside from their smaller length, the U18B had many similar design qualities to its larger siblings. The other spotting feature common to many, but not all, U18Bs was the frequent use of EMD Blomberg trucks from trade-in locomotives.

In these trade-in locomotives lies the root of the U18B's sales problem. The appeal of the U Boat - indeed of diesels in general - is the ability to multi-task.

In the early 1970s, most railroads were short on cash and long on lines of older four-axle locomotives which could be used as-is or more economically rebuilt for the light duty assignments marketed for the U18B. A rebuilt GP9 would offer similar utility at a fraction of the cost. When new locomotives were purchased, railroads preferred models that gave them the most options for their price. Larger power was also preferred as these big new locomotives could often replace a greater number of smaller and older models - leaving plenty of power for the branch lines and locals.

Of the 163 U18Bs built, 105 were sold to the Seaboard Coast Line. The majority of the remainder were sold to Mexico, making this a very rare locomotive in most of the United States.

Most of the locomotives have gone on to have long service lives however. The Seaboard Coast and Maine Central units all went on to serve succeeding railroads. Today, several dozen can be found working on shortlines. Some are now on their fourth or fifth owner. None have yet been set aside for preservation.

There were marketing plans for a B18-7, the succeeding model in the Dash 7 line, but none were ever built.

Original Operating Railroads

• Ferrocarriles Nacionales de México - 45
• Maine Central - 10
• Providence and Worcester - 1
• Seaboard Coast Line - 105
• Texas Utilities - 2

Models

Despite having only a few buyers, the U18B has been reproduced in some of the most popular scales. More adventurous modelers in other scales could also build their own. With common parts with several other GE locomotives, it would be a reasonable model to kitbash.

The locomotive is actually well suited to most model railroads. It's compact body makes it the perfect light road engine for your local freights or smaller switching layouts. And as a relative oddity, it's sure to attract a little extra attention.

The following list includes all known models produced to date:
HO Scale: Intermountain
S Scale: Gilmaur - brass body kit