The Dash 8 Series is a line of diesel-electric freight locomotives built by GE Transportation. It replaced the Dash 7 Series in the mid-1980s, and was superseded by the Dash 9 Series for freight usage and the Genesis Series for passenger usage in the mid-1990s.
All models of the Dash 8 Series are powered by a 16- or 12-cylinder, turbocharged, GE 7FDL 4-stroke diesel engine.
Specifications
The design of the Dash 8 Series is based upon that of the Dash 7 Series. The biggest changes introduced during the production of the Dash 8 Series were the first use of a microprocessor-equipped engine control unit in a diesel locomotive, and the adoption of a modular system in the construction of the vehicle body.
The Dash 8 locomotive bodies were assembled from several modules, creating a combination to fit the length of the chassis. On models with a traditional narrow short hood, the part of the equipment room immediately behind the cab is taller than the top of the rounded cab roof, giving those models a distinctive appearance. On all models, that part of the equipment room houses the cooling fans for the dynamic braking system.
Traction motors of Dash 8 locomotives were powered by direct current.
Construction history
The Dash 8 prototype was completed in 1984. Manufacture of the improved production units started in earnest in 1987. Early versions of the Dash 8 were manufactured on the Dash 7 production line, but their general appearance was different. The Dash 8-40C, introduced in 1987, featured improved reliability.
Nomenclature
The naming of the Dash 8 Series, and that of its various models, corresponded initially with that of its predecessor, the Dash 7. So, for example, "B32-8" designated a B-B configured Dash 8 Series locomotive.
After product improvements were made to the line in 1987, the official designations for models in this series changed to "Dash 8...", as shown below. However, for simplicity many railroads decided to use designations which follow the pattern of the Dash 7 line. For example, the Dash 8-40C is usually rendered as "C40-8".
The "W" suffix used for some models indicates the then-optional wide-nose "North American" safety cab.
Four axle models
Common features
Specifications common to all Dash 8 Series four axle models are as follows:
AAR wheel arrangement: B-B
Prime mover: GE V-type 7FDL-16 V16 engine, 7FDL-12 V12 for B32 models
Dash 8-32B (B32-8)
This model was manufactured between 1984 and 1989
49 examples of the model were built for North American railroads.
All but 4 of these units were ordered by Norfolk Southern.
The others were 3 units ordered by Burlington Northern Railroad, and a GE demonstrator unit.
Prime mover: GE 12-cylinder V-type 7FDL-12 four stroke diesel engine
Power output:
Dash 8-36B (B36-8)
This model, a one-off, was the original Dash 8 prototype, built in 1983.
Power output:
Dash 8-39B (B39-8)
A total of 145 examples of this model were manufactured from 1984. Its external appearance is almost the same as that of the later Dash 8-40B model, with the obvious exception of the trucks.
The first three Dash 8-39Bs were built for Atchison, Topeka and Santa Fe Railway (ATSF). A fourth example of the model, a GE demonstrator designated as a Dash 8-39BE (or B39-8E), was converted from the original Dash 8 prototype.
There were also two much larger groups of this model: 102 Dash 8-39BEs were fabricated for Locomotive Management Services (Reporting mark: LMX) and placed on long term lease to Burlington Northern Railroad.
The remaining 40 were built for the Southern Pacific Railroad.
Power output:
Dash 8-40B (B40-8)
In 1988 and 1989, a total of 150 units of this model were produced.
Substantial orders for the model came from ATSF (40 units), Conrail (30 units), New York, Susquehanna and Western Railway (24 units), and the model's biggest customer, St. Louis Southwestern Railway (54 units).
There were also small orders from Providence and Worcester Railroad (4 units), the United States Department of Energy (Savannah River Site), and a GE demonstrator unit.
Power output:
Dash 8-40BW (B40-8W)
Eighty three examples of this model were built for ATSF in the early 1990s. ATSF was the only railroad to order it. There was also one GE prototype and testbed, rebuilt from the prototype B39-8E.
The "W" suffix to this model's name indicates that it differs from the B40-8 in having a "wide nose" safety cab.