The GE (General Electric) B39-8 (Dash 8-39B, or simply "Dash 8") is a type of four-axle, 3,900hp diesel locomotive first built in 1984, and again from 1987-1988 (with official production beginning in May 1987).
LMX B39-8

An LMX B39-8; one of the many owned by the leasing company.

145 were built, and can still occasionally be seen on various different railroads and railways throughout North America operating in lease service, but are often considered to be somewhat rare.

Southern Pacific (SP), LMX Leasing, and Santa Fe (ATSF) were the only customers to purchase the model.

Many have since been retired, while others have been sold to various shortlines and/or regionals. Some have been scrapped, while others are used for spare parts.


During the mid-1980's, major US Class 1 railroads were in the process of retiring aging, previous generations of GE, ALCO, and EMD diesels (such as the "Century" Series units from ALCO, first-generation diesels like the GP7 from EMD, and various preceding Universal Series models like the U25B from GE) which deemed to be "outdated" by most railroads and contrary to the FRA standards of that time (regarding the 1970's Energy Crisis and subsequent 1983 recession), and began a time or new generation when railroads became interested in purchasing more modern, high-horsepower, fuel-efficient, and otherwise more economical diesel locomotives to replace the preceding so-called "ancient" diesels which either consumed large amounts of fuel, or had outdated equipment and components which proved to be costly to replace and/or maintain, on top of having drastically lower amounts of horsepower deemed to be "ineffective" for long, heavy-haul applications in the rapidly growing freight market further caused by the diminishing carriers which went under as a result of various mergers, bankruptcies, and acquisitions.

GE's solution or answer to this problem, was by developing the Dash 8 line (originally code-named "Super 7") of economical, high-tech, high-horsepower diesel-electric locomotives which included microprocessor controls which then featured automatic engine starters, electronic braking systems, a Doppler-controlled wheelslip system, as well as having an advanced engine cooling system reminiscent to EMD's 'Tunnel Motor' cooling system design used on the SD40T-2 and other subsequent "Tunnel Motor
BC B39-8

A freshly-painted BC Rail B39-8 during the CN merger in late-2001.

" series models, while also retaining a similar design found on previous GE models. The testbed line for the early Dash 8 models officially debuted with the introduction of said models previously dubbed as the "Super 7" "B32-S7", "B36-S7", "B39-S7", "C32-S7", "C36-S7", and the so-called "C39-S7"; all which were eventually given the "Dash 8" suffix upon early test runs with host railroads prior to production of some of the models within the line.

The B39-8 was originally one of the so-called "Super 7" testbed units: having three built specially for ATSF for field evaluation purposes. Yet the B39-8 itself was actually one of the models to officially develop the Dash 8 line of diesel locomotives produced from GE to its current renowned status. Thus, the B39-8 was a complete success, and became an almost instant rival to EMD's GP50, despite not being very popular amongst carriers at the time as a result of the declining four-axle diesel locomotive market. Yet, not too long after the B39-8's initial production, the more popular and externally-similar B40-8 was introduced, thus eliminating the B39-8 entirely from GE's catalog six-axle C40-8 and C40-8W overtook the later.

The B39-8 was originally built or intended for high-speed intermodal freight service, and served as one of the final attempts to encourage railroads to order or purchase four-axle models rather than resort to buying more expensive (yet increasingly popular) six-axle types or models of diesels. Though the model didn't receive many orders or gain much popularity, partly due to its 3,900hp rating and the simple fact that it was a four-axle model, which unfortunately became part of the four-axle diesel locomotive's diminishing popularity rather than reviving it. However, the model became popular with the Southern Pacific's rapidly-growing intermodal service along the West Coast, for SP was one of the only other customers besides LMX Leasing through Burlington Northern to acquire and utilize the model for high-speed mainline freight service. BN on the other-hand, utilized their leased B39-8 units as part of a "Power by the Hour" agreement which lasted until around 2006 through successor BNSF. Other than the latter, ATSF was the only other customer; despite only owning the three testbeds in which they hosted, and further ordering a mass of B40-8 units instead of production B39-8's. They served the SP, BN, and ATSF up until the mid-1990's during the "Mega Merger" era: when the ATSF merged with the Burlington Northern (BN) in 1995-1996 while the UP acquired the SP in 1996. The ATSF testbed units were ultimately scrapped prior to the BNSF merger.

They were eventually used as spare units until ultimately becoming retired or re-regulated due to four-axled diesel locomotives no longer being a priority on mainline trains for Class 1 systems. Though, the remainder are now used as heavy-duty yard switchers for hump yard service or are used for local service.

Several B39-8 units still remain on UP's roster but are only used as spare units, or for local or yard service, aside from most having been up-rated to 4,000hp; essentially becoming B40-8 units. The majority of LMX units (including several SP units retired following the UP-SP merger) however, were sold to BC Rail (British Columbia Railway) shortly before the acquisition from CN (Canadian National) in 2002. They are now currently in storage, and are awaiting their next fate. The remainder of existing LMX B39-8's are currently in operation throughout various shortline or regional companies, while others have since been acquired by subsequent leasing companies.


The B32-8 was the B39-8's 3,200hp counter-part which inspired the development for the B39-8. Three were built, and were demonstrated to the Burlington Northern (BN) between 1984 to 1991 and have since remained as part of GE's test fleet following their return from BN, for BN decided to sign a contract with LMX Leasing to utilize their fleet of B39-8 units in favor of ordering B32-8's.
GECX 832

GECX #832: the B32-8E test unit.

A similar type of locomotive known as the B32-8E (the "E" meaning "enhanced") was built specially for Norfolk Southern (NS), which is essentially a downgraded, 12-cylinder variant or version of the B40-8.

As of 2013, two of the three B32-8 prototypes remain as well as GECX #809 (the former B36-8 testbed) and GECX 832 (a B32-8E demonstrator); all which are owned by GECX (General Electric Company Leasing or General Electric Corporation Leasing) as part of their test fleet for testing and evaluation purposes.


There is often a confusion between the B39-8 and the B40-8, as well as the B32-8E.

  • The main way of distinguishing the main physical or external features (spotting features), is by the radiator "fins" as well as the truck length, carbody height, fuel tank size, and owner.
  • The B39-8E ("E" meaning "Enhanced") is the improved or enhanced version of the original, and is considered to be the "slanted-cab", "wedged-cab", or "Spartan cab" version of the production B39-8. The "E" is often used to help distinguish from the original "round-cab" testbeds, as well as being an "Enhanced" version of the original. Though, some rosters often use the "E" distinction to help differentiate re-rated B40-8 units from original B39-8 units in some context.
  • Many B39-8's have since been re-rated to 4,000hp, essentially making them "B40-8's" (while said subsequent B40-8's have since been de-rated at 3,900hp or at approximately 3,950hp, dubbing them as a "B39-8E"). Therefore, the "E" suffix is commonly used to distinguish the latter at times.


Model B32-8 B36-8 B39-8
Production Dates 1984 1983 1984-1988
Total Built 3 1 145
Length 63' 7" 66' 4" 66' 4"
Wheel Arrangement B-B B-B B-B
Engine 7FDL-12 7FDL-16 7FDL-16
Horsepower Rating 3,200 3,600 3,900
Alternator GMG186 GMG186 GMG186
Traction Motors 752AG 752AG 752AG
Weight x 1,000 lbs. 262-280 274-280 274-280

Production RosterEdit

Owner Quantity Road Numbers Notes
ATSF (Santa Fe) 3 7400-7402 Scrapped between 1993-1994
LMX Leasing (Locomotive Leasing Services) 102 8500-8599, 8503 (2nd), 8540 (2nd) Long-term lease to BN. Original 8503 and 8540 returned to GE to become test units GECX 8000-8001.
Southern Pacific 40 8000-8039 Sold to BC in 2000-2001; currently retired. Remainder with UP; uprated to 4,000hp and classified as "B40-8".


The Burlington Northern once shared a long-time contract with LMX Leasing over their use of B39-8 units (as with Oakway Leasing's fleet of EMD SD60 units). The contract lasted long into the BNSF merger, yet was dissolved around 2005-2006.

Like with their only SD60 units, the BN briefly used a set of demonstrator B32-8 units leased from GE before eventually receiving a lease offer from LMX which proved to be more affordable as opposed to actually owning their own fleets of B32-8 or B39-8 units.

The ATSF had the smallest B39-8 fleet, having only 3 (ATSF #7400-7402); all of which were the original demonstrator testbed units which resemble the original B32-8 units in terms of the distinct "hunch-back" (or "hump-back") style cabs, thinner radiator wings (fins), and more symmetrical rear hood reminiscent of the C32-8 and C39-8. All three were given distinct numberboards, which were white with black numbering as opposed to the usual or more common black with white numbering. The three testbeds have since been scrapped prior to the BNSF merger.

CN's fleet of former B39-8 units from SP, SSW, and LMX heritage have since been retired and are awaiting to be scrapped or purchased by a leasing company or shortline railroad.

The B39-8 was BC Rail's last type of locomotive purchased by the railroad, as well as having the most short-lived career. Most remaining BC-painted B39-8 units still have their "factory-fresh" paintscheme due to the fact that some were never even used in active service due to the CN merger, meaning that they didn't prove to be very popular with their new owner (the CN only utilized a handful of these units as spares, yet neglected using them in favor of their once vast SD40-2 fleet).

Various shortline railroads such as the P&W (Providence And Worcester Railroad) and the Seminole Gulf Railway own several former LMX, SP, and SSW B39-8's (aside from converted B40-8 units rated at only 3,900hp).

Oddly, the SP and SSW had their B40-8 units painted with additional numbers applied to the upper part of the front plow. The numbers (obviously) since became covered, removed, or hidden with dirt, grime, or exhaust (aside from simply being painted over).

GECX #809 (originally GECX #606) was originally the B36-8 testbed built in 1982. The unit was then rebuilt into a B39-8 1986, and was enhanced with updated features which were present on production units. Not too long after, the unit was then rebuilt and renumbered once again in 1988 and fitted with an early version or prototype of the North American Safety Cab (or "wide-cab") which inspired the development for the final design, which was subsequently used as the basis for the design of the B40-8W ordered by ATSF, and further debuted on the C40-8W years earlier.