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EMD BL2
EMD BL2
from Wikipedia
EMD BL2
Janesville & Southeastern #52 at the National Railroad Museum.
Type and origin
Power typeDiesel-electric
BuilderGeneral Motors Electro-Motive Division (EMD)
ModelBL2
Build dateSeptember 1947 – May 1949
Total produced59
Specifications
Configuration:
 • AARB-B
Gauge4 ft 8+12 in (1,435 mm)
Prime moverEMD 16-567B
Engine typeV16
GeneratorEMD D-12A
Traction motors(4) EMD D-17-B or D-27-B
Cylinders16
Performance figures
Power output1,500 hp (1,100 kW)
Tractive effort56,200 lbf (250 kN)
Career
OperatorsSee "original Owners"
LocaleUnited States

The EMD BL2 is a model of diesel-electric locomotive built by General Motors Electro-Motive Division (EMD). A total of 58 units (plus a single BL1) were built between 1947 and 1949.[1] The BL2 was not very successful, as it was unreliable and occupied a gap between carbody and hood units, which resulted in it suffering from the drawbacks of both designs. However, lessons learned from the BL2 were incorporated into EMD's next design, the GP7.[2]

History

[edit]

EMD's diesel program was well underway by the late 1940s thanks to the success of the company's F- and E-units. While the F-units in production were great for moving trains over the railroad, their full-width carbody made it difficult for locomotive crews to see to the rear of the locomotive while switching. This was considered an acceptable sacrifice for a mainline locomotive, which was expected to do little switch work, since the full-width carbody type was considered much more handsome and stylish. By 1948, competitors Alco, Baldwin, and Fairbanks-Morse had introduced road switcher locomotives, which used the narrow hood and full walkway of a switcher locomotive with a longer frame and the high-speed trucks of a road locomotive. These locomotives were successful at displacing steam from secondary services such as local and branch-line work.

EMD developed the BL1, basing it on the F3 and using the same bridge-truss carbody construction as the F-unit (as opposed to the weight-bearing frame of a true road switcher locomotive like the Alco RS-1) with the body cut away behind the cab to provide visibility to the rear.[3] The first BL1 was EMD Demonstrator #499, built in September 1947. The BL1 Demonstrator was EMD Project 89499, thus the 499 Demonstrator number. The BL in the model name stood for "Branch Line", indicating that EMD felt the locomotive was best suited for light traffic and frequent switching chores.[2] The BL1 was built with a light-weight underframe and draft gear and no multiple unit (MU) capabilities, as it was expected to operate as a single unit.[3] However, MU capability was later added to the BL1.[3]

In response to feedback from the railroads, the visually-identical BL2 was built with a heavier frame and draft gear and MU capability.[3] The production BL2 used the standard Woodward, Inc. electro-hydraulic governor and notched throttle as used in the F3 (as opposed to the air-actuated throttle with which the BL1 was originally built). The BL2 could be equipped with a train-heating steam generator for passenger service, identified by an exhaust stack between the panes of the front windshield. The B&M, C&O and Rock Island ordered such units.[4]

Limiting the locomotive's success were several mechanical and ergonomic drawbacks. The BL2 was expensive and time-consuming to build because of its unique carbody design. Rather than being built in small segments which could be moved to another area for final assembly, the BL2 had to be built entirely in once place.[3] The mechanical components in the engine compartment were difficult to access and maintain, reducing its appeal among railroad shop crews. The locomotive's carbody lacked the full-length walkways of a true switch engine (a mistake not repeated on the subsequent "GP" series of diesels or other road switchers), making it difficult for the brakeman or switchman to move from one point on the locomotive to another during switching operations. Finally, although the industrial designers at EMD tried to build a carbody that evoked high-class passenger trains while retaining the utilitarianism of railroad work, the design never became popular. EMD applied the lessons learned from the BL2's lack of success in developing the GP7.[3]

Original owners

[edit]
Railroad Quantity Road Number
Bangor and Aroostook 8 550-557 (later 50-57)
Boston and Maine Railroad 4 1550–1553
Chesapeake and Ohio Railway¹ 14 80-85 (Ordered by Pere Marquette Railroad prior to merger), 1840–1847
Chicago and Eastern Illinois Railroad 2 1600-1601 (later 200-201)
Chicago, Indianapolis and Louisville Railway ("Monon") 9 30-38
Chicago, Rock Island and Pacific Railroad 5 425-429
Electro Motive Division 1 499 (BL1 demo, sold to C&EI 1602, later 202)
Florida East Coast Railway 6 601-606
Missouri Pacific Railroad 8 4104-4111
Western Maryland Railway 2 81-82
Total 59

Preservation

[edit]

The following BL2s have been preserved:


References

[edit]

Additional Reading

[edit]
  • Pinkepank, Jerry A. (1973). The Second Diesel Spotter's Guide. Kalmbach Publishing Co., Milwaukee, WI. ISBN 0-89024-026-4.
  • Dover, Dan; Skinger, Ed; Cuisinier, Win. "BL2..... A Final Study". Extra 2200 South (46): 20–24. Drawings by Win Cuisinier (Preston Cook).
Revisions and contributorsEdit on WikipediaRead on Wikipedia
from Grokipedia
The EMD BL2 is a four-axle B-B diesel-electric developed by the Electro-Motive Division (EMD) of as an early attempt at a versatile switching and branch-line unit, featuring a semi-streamlined carbody adapted from the F3 with modifications for improved visibility. Powered by a 1,500-horsepower 16-cylinder 567B engine, it measured 54 feet in length, weighed 230,000 pounds, and had a top speed of 65 mph, with starting of 55,000 pounds. Only 59 examples were produced between February 1948 and May 1949, including a single BL1 prototype converted to BL2 standard, marking it as one of EMD's least successful postwar designs despite paving the way for the more popular GP7. Introduced amid the rapid transition from to diesel power on American railroads, the BL2 aimed to fill a niche for light-duty service by incorporating end platforms, rear cab windows, and a beveled engine compartment to enhance switching visibility over traditional freight units. However, its complex carbody construction, lightweight frame, and lack of exterior walkways complicated and limited its appeal, while high production costs—stemming from custom fabrication rather than standardized assembly—deterred buyers. were confined to nine railroads, with the largest orders going to the Chesapeake & Ohio (14 units), Monon (9 units), and Pacific (8 units), alongside smaller fleets for lines like the Bangor & Aroostook and East Coast. Competition from Alco's more practical RS-2 road switchers and railroads' preference for cascading older F-units further contributed to its commercial failure, leading EMD to abandon the BL series after just over a year of production. Despite its shortcomings, the BL2's experimental design influenced subsequent EMD models by highlighting the need for better ergonomics and cost efficiency in road-switcher layouts, ultimately contributing to the success of the GP7 introduced in 1949. Today, at least seven BL2s survive in preservation, with several operational on tourist railroads, including No. 81 at the and Bangor & Aroostook No. 557 at the Cole Land Transportation Museum, serving as rare examples of transitional diesel technology.

Design and Development

Origins and Purpose

In the mid-1940s, as U.S. railroads accelerated the transition from steam to diesel power following World War II, there was a growing demand for versatile locomotives suited to light-duty branch line service and switching operations. Electro-Motive Division (EMD) recognized that a significant portion of the rail network consisted of branch or secondary lines, necessitating efficient replacements for aging steam locomotives in these roles. EMD's F-unit series, while successful for mainline freight and passenger service, presented significant limitations for yard and work, including poor forward visibility due to the cab-forward carbody design that obstructed operators' sightlines during switching maneuvers. To address these shortcomings, EMD aimed to develop a "" (BL) locomotive with enhanced maneuverability and bi-directional visibility, incorporating features like rear cab windows and a modified hood layout derived from the F3 model. This design sought to improve operator efficiency in short-haul applications without the need for frequent unit rotations. Market analysis at the time highlighted the need for a unit that balanced power and weight, positioned between heavy road locomotives and basic switchers, to serve the surge in localized freight handling. EMD positioned the BL2 as a response to competitive road-switcher offerings from manufacturers like Alco, which had entered the market earlier in the decade, filling a gap for cost-effective, adaptable diesel power on secondary routes.

Prototype BL1

The prototype BL1 was constructed in 1947 as a one-off demonstrator at the Electro-Motive Division (EMD) plant in . This unit tested core design elements of the BL series, including a 1,500 hp EMD 16-567B prime mover, B-B truck configuration with four-wheel trucks, and an experimental semi-streamlined cab-forward body featuring a beveled engine compartment and rear cab windows to enhance bi-directional visibility. End platforms and footboards were incorporated for switching duties, while the design retained some F-unit streamlining elements but omitted full-length walkways. The BL1 served as a response to visibility limitations in EMD's F-unit cab locomotives, prioritizing improved sightlines for engineers during and yard operations. As EMD demonstrator No. 499, the BL1 underwent initial testing in late 1947 and early 1948, including yard switching trials and short runs to evaluate its performance in light-duty service. These phases highlighted several issues, such as frame flexing under load from the lightweight 230,000-pound chassis, which proved inadequate for sustained heavy-duty applications, along with a complex carbody that hindered engine and generator access. Additionally, the unit's air-powered system lacked multiple-unit (MU) compatibility, limiting its ability to operate in consists with other locomotives. Performance data from these tests directly informed refinements for the production BL2, including frame reinforcement for better structural integrity and the addition of standard mechanical throttle and MU controls. The BL1 was subsequently rebuilt to BL2 specifications in early 1948 and sold to the Chicago & Eastern Railroad, where it was renumbered as No. 202.

BL2 Production Model

The production of the EMD BL2 occurred from February 1948 to May 1949 at the Electro-Motive Division's facility in , resulting in 58 production units alongside the single BL1 prototype (converted to BL2 standard) for a total of 59 locomotives. This timeline marked EMD's initial foray into hood-type road-switcher designs, bridging the gap between streamlined cab units like the F-series and more versatile general-purpose models. The BL2 retained much of the BL1's semi-streamlined carbody aesthetic but incorporated practical enhancements for and yard service, emphasizing durability and operational flexibility over speed. Key refinements in the BL2 addressed limitations observed in the prototype BL1, particularly its frame instability under load, by incorporating a heavier frame and reinforced draft gear that boosted the overall weight to 230,000 pounds for greater stability on uneven trackage. Additional changes included the addition of multiple-unit (MU) receptacles to enable synchronized operation with other locomotives, a feature absent in the BL1, and standard mechanical throttle controls. These modifications, while enhancing reliability, complicated the manufacturing process due to the custom carbody fabrication, which required extensive hand-welding and assembly rather than standardized modular construction. The BL2's production faced significant challenges, including a high per-unit cost driven by the labor-intensive custom bodywork, which limited its appeal and resulted in only modest orders from nine railroads. This bespoke approach contrasted with EMD's more efficient assembly lines for F-units, contributing to the model's short production run and commercial underperformance. Ultimately, lessons from the BL2's cab layout and AAR Type B truck design directly influenced the development of the GP7, introduced in October 1949, which adopted a simpler hood-unit configuration with full-length walkways for broader versatility and became one of EMD's best-selling locomotives.

Technical Specifications

Prime Mover and Power System

The EMD BL2 was powered by a 16-567B prime mover, a V16 featuring scavenging for efficient air intake and combustion. This produced 1,500 horsepower (1,100 kW) at a rated speed of 800 rpm, providing reliable output tailored for sustained low-speed operations on branch lines. The emphasized durability and simplicity, with uniflow scavenging to minimize exhaust residuals and optimize power delivery under varying loads. The locomotive's electrical transmission system utilized an EMD D12 main generator to convert mechanical energy from the prime mover into electrical power, which was then supplied to four D27B traction motors—one per axle—for propulsion. This setup delivered a starting tractive effort of 55,000 pounds-force (250 kN) at 25% adhesion and a continuous tractive effort of 40,000 pounds-force at 9.3 mph, enabling effective hauling of freight trains at moderate speeds. The B-B wheel arrangement contributed to stability during these duties by distributing weight evenly across the four powered axles. Fuel and auxiliary systems supported extended service, with a 800-gallon diesel tank providing sufficient capacity for typical runs without frequent refueling. was incorporated as a standard feature, allowing regenerative slowing by converting motor-generated electricity into heat via grid resistors, which enhanced control on downgrades. These features, combined with a gear of 62:15, geared the BL2 for a maximum speed of 65 mph while prioritizing over high-velocity performance. The 567-series engine achieved specific fuel consumption rates of approximately 0.38 pounds per brake horsepower-hour at rated load, reflecting the era's advancements in two-stroke diesel technology for rail applications. This metric underscored the BL2's suitability for economical operation in low-demand environments, balancing power output with economy.

Body and Chassis Features

The EMD BL2 employed a cab-forward body layout optimized for yard and duties, with an overall length of 54 feet to balance maneuverability and stability. The high short hood at the leading end maximized forward visibility, while the full-width cab incorporated large windows on multiple sides to support bi-directional switching operations. Centered controls within further enhanced ergonomic efficiency for engineers accustomed to versatile locomotive handling. This configuration, enabled by the locomotive's 1,500 horsepower output, permitted a relatively lightweight structure suitable for lighter rail infrastructure. The chassis featured robust cast steel B-B trucks in a Type B arrangement, each with a 9-foot and 40-inch wheels to minimize and improve reliability under frequent starts and stops. Rated for a total weight of 230,000 pounds, these trucks provided adequate for the BL2's intended service without overburdening branch lines. The absence of full-length walkways along the body prioritized a streamlined profile, though end platforms facilitated ground-level access during switching. Styling on the BL2 blended semi-streamlined from earlier cab units with functional road-switcher elements, resulting in a distinctive appearance often described as unconventional. Crew safety and comfort were prioritized through integrated handrails along the body edges and pilots, along with multiple steps for secure mounting and dismounting. Cab insulation helped mitigate and extremes, marking a step forward from the drafty environments of steam-era locomotives and easing the transition for operators in the diesel age. Footboards on the front and rear pilots further supported interactions during yard work.

Production and Operators

Build Details and Numbers

The Electro-Motive Division (EMD) of constructed a total of 59 BL-series locomotives exclusively at its assembly plant, comprising one experimental BL1 demonstrator and 58 production BL2 units with serial numbers spanning 4449 to 8617. commenced with the BL1 in February 1948, transitioning to the BL2 production model in April 1948; output peaked in 1948 with more than 30 units completed across multiple orders before tapering in 1949 amid evolving railroad demands for general-purpose locomotives. The BL2 incorporated minor refinements from the BL1 , such as an upgraded electro-hydraulic system, which streamlined subsequent assembly processes.

Original Owners and Orders

The EMD BL2 saw orders from nine railroads between April 1948 and May 1949, following successful demonstrations of the BL1 prototype earlier that year, with a total of 59 units produced to meet demand for versatile power. These initial purchasers, primarily mid-sized regional carriers, acquired the BL2 as a diesel-electric replacement for aging on low-traffic branches, appreciating its centered cab design for enhanced visibility during bi-directional switching and local freight operations compared to traditional F-unit cab-forward layouts. Some orders specified multiple units for mixed freight and passenger service on secondary lines, reflecting the BL2's intended role in transitioning post-World War II railroading from steam to diesel. The largest order came from the Chesapeake & Ohio Railway, which purchased 14 units (road numbers 80–85 and 1839–1847) starting in June 1948, with the initial batch ordered by its subsidiary Pere Marquette prior to their merger; these were deployed on and Midwest branches to handle light freights and occasional passenger runs, painted in the C&O's classic blue and yellow livery. The Monon Route (Chicago, Indianapolis & Louisville Railway) followed with nine units (30–38) across three batches from 1948 to May 1949, motivated by the need to modernize and short lines serving agricultural and industrial traffic, where the BL2's visibility aided tight-radius operations; they received the Monon's distinctive maroon and gray scheme. Other significant orders included eight units each to the Bangor & Aroostook Railroad (550–557, delivered March–April 1949) for potato and lumber hauls on northern branches, emphasizing the BL2's suitability for remote, low-volume routes in their green-and-yellow paint, and to the Missouri Pacific (4104–4111, May–September 1948) for similar replacement duties on and feeders, in the road's eagle-blue livery. The acquired six units (601–606, October–December 1948) to support post-war recovery on Florida's east coast lines, valuing the design's reliability in humid conditions for fruit and merchandise trains. Smaller orders rounded out production, such as five units to the Chicago, Rock Island & Pacific (425–429, December 1948–January 1949) for Midwest branch switching, four to the Boston & Maine (1550–1553, July–September 1948) equipped for passenger locals in their navy blue scheme, three to the Chicago & Eastern (1600–1601 plus the ex-demonstrator BL1 as 1602, December 1948) for coal drags, and two each to the (81–82, October 1948) for Appalachian short hauls in black and orange, highlighting the BL2's appeal to carriers prioritizing operational flexibility over high-volume mainline power.
RailroadUnits OrderedRoad NumbersDelivery PeriodKey Motivation
Chesapeake & Ohio1480–85, 1839–1847June 1948–March 1949Branch freight and passenger on Midwest lines
Chicago, Indianapolis & Louisville (Monon)930–38April 1948–May 1949Agricultural and industrial short lines in /
Bangor & Aroostook8550–557March–April 1949Potato/lumber branches in northern
Missouri Pacific84104–4111May–September 1948Feeder lines in /
Florida East Coast6601–606October–December 1948East coast freight recovery in
Chicago, Rock Island & Pacific5425–429December 1948–January 1949Midwest switching operations
Boston & Maine41550–1553July–September 1948New local passenger/freight
Chicago & Eastern Illinois3 (incl. BL1)1600–1602December 1948 coal and drag freights
Western Maryland281–82October 1948Appalachian short hauls

Operational History

Early Service and Challenges

The EMD BL2 locomotives entered service primarily on secondary lines and branch routes for freight switching and short-haul operations, reflecting the needs of their original owners for versatile units in lighter-duty applications. For instance, the Bangor & Aroostook Railroad deployed its eight BL2s (numbered 550–557) on routes such as the Aroostook Valley line between 1948 and the mid-1950s, handling potato freight and mixed trains in northern Maine's rugged terrain. Similarly, the Chesapeake & Ohio assigned its 14 units to branch line duties in Appalachia, while the Monon Route used its nine BL2s for switching and local freights in the Midwest. These deployments aligned with the BL2's design intent as a branch-line road-switcher, often replacing older steam locomotives on uneven tracks where full mainline power was unnecessary. Early operations revealed significant challenges stemming from the BL2's complex carbody and lightweight frame, which restricted its suitability for heavier loads and prolonged its downtime. Access to and main generator proved difficult due to the intricate "branch-line" styling inherited from earlier , leading to higher repair costs and labor intensity compared to simpler competitors. Railroads reported frequent issues with the frame's limited strength, which was adequate for yard work or light trains but prone to stress in multiple-unit (MU) consists or on grades, often necessitating or restrictions on usage. Operator complaints highlighted the cab's poor , including inadequate visibility from the semi-streamlined nose and the absence of full-length walkways, which complicated interactions and contributed to a rough ride on branch tracks. Overall, the BL2's service life varied by operator, with many fleets replaced within 10 to 20 years due to reliability issues. Economically, while the shift to diesel offered over , the BL2's manufacturing complexity and high upkeep deterred broader adoption, with production halting after just 58 customer units in favor of the more robust GP7.

Retirement Patterns

The retirement of EMD BL2 locomotives accelerated in the early as original owners phased them out in favor of more powerful and versatile models like the GP7 and GP9, which offered higher horsepower and improved reliability for expanding freight demands. The Boston & Maine, for instance, retired its four BL2s between 1960 and 1961 due to these operational shifts. Similarly, the Chesapeake & Ohio decommissioned all 14 of its BL2s in 1962, trading them directly to EMD for new GP30 units, after which the locomotives were scrapped. By the mid-1960s, retirements became more widespread amid railroad mergers and rationalization efforts, with major scrapping occurring between 1965 and 1970 as fleets were streamlined. The retained its two BL2s in service until the early , after which both units were preserved. The Rock Island Line retired its five BL2s prior to its 1975 bankruptcy, contributing to the wave of disposals as the railroad faced financial pressures. Most of the 58 BL2s built were traded in or scrapped by 1972, reflecting the model's limited production run and the rapid evolution of diesel technology. A smaller second-hand market emerged in the and , with approximately 20 units resold to regional carriers, short lines, and industrial operations, where they continued in lighter service—such as switching and branchline duties—into the . The Bangor & Aroostook Railroad, which owned eight BL2s, retained several in active use longer than most operators, with some not retired until the early before entering secondary markets. These resales often involved units from larger roads seeking to offload older equipment. Key factors driving these retirements included the BL2's against higher-horsepower successors capable of handling heavier trains, as well as early challenges like restricted access that increased downtime and costs. Parts for the BL2's 16-cylinder 567B prime mover became increasingly scarce as EMD shifted production to updated variants, further hastening decommissioning.

Preservation and Legacy

Surviving Examples

Out of the 59 EMD BL2 locomotives produced between 1948 and 1949, seven units are known to have survived into preservation as of 2025, representing a rarity due to widespread scrapping during the mid-20th century diesel transition. Of these, at least four are operational, highlighting ongoing efforts to maintain these transitional road-switchers for educational and heritage rail operations. The most notable recent preservation activity involves the Hoosier Valley Railroad Museum in North Judson, Indiana, which acquired two former Bangor & Aroostook BL2s (Nos. 52 and 56, later Saratoga & North Creek) via lease in 2021. No. 52 underwent a comprehensive two-year restoration and debuted in on September 2, 2023, marking the first operational BL2 return in decades and enabling runs on the museum's line. No. 56 remains in storage at the museum, with potential for future restoration to operational status. Other preserved examples are primarily in static display or limited-service roles:
Unit No.Original OwnerCurrent LocationStatus
52Bangor & AroostookHoosier Valley Railroad Museum, North Judson, INOperational (restored 2023)
56Bangor & AroostookHoosier Valley Railroad Museum, North Judson, INStored, operational potential
82Durbin & Greenbrier Valley Railroad, Elkins, WVOperational
81, , MDStatic display
557Bangor & AroostookCole Land Transportation Museum, Bangor, MEStatic display
54 (orig. 554)Bangor & AroostookStourbridge Line, Honesdale, PAOperational
32MononKentucky Railway Museum, New Haven, KYOperational
These survivors serve as important artifacts of EMD's early road-switcher experimentation, with parts from scrapped units occasionally supporting restoration projects at various museums. Discussions around repowering select examples with period-accurate components continue, though no major initiatives beyond the 2023 effort have advanced as of November 2025.

Influence on Later Locomotives

The EMD BL2's cab-forward configuration, featuring a sloped nose and extensive windowing to enhance visibility during and switching operations, influenced the GP7's hood-unit design with centered cab introduced in 1949, which supported short-hood-forward operation for improved crew sightlines in versatile service. Likewise, the BL2 employed B-B trucks with Blomberg suspension, a setup retained in the GP7 to ensure stability and traction across varied rail conditions. These elements addressed limitations in earlier cab-unit locomotives like the F3, from which the BL2 was derived, but the BL2's cast frame proved prone to cracking under multiple-unit operation stresses, leading EMD to adopt a stronger welded in the GP7 that better withstood heavy service demands. Beyond these specifics, the BL2's transitional role highlighted the need for hood-unit architectures in subsequent EMD models, promoting through full-length walkways and simplified body panels that facilitated maintenance and adaptability in the 1950s diesel fleet. The locomotive's 1,500 hp 567B prime mover also established a power benchmark for the GP series, enabling broader application in freight and roles. Furthermore, the BL2's production challenges, including its costly and complex carbody, yielded valuable lessons in cost control that influenced the more streamlined and affordable SW-series switchers, ensuring EMD's designs balanced performance with economic viability. In contemporary railroad heritage, the BL2 is examined as a pivotal example of early diesel evolution, illustrating the shift from specialized cab units to general-purpose road-switchers, and it features in historical simulations, scale models, and museum exhibits to demonstrate transitional engineering concepts. Despite its limited production of just 59 units between 1948 and 1949, the BL2's shortcomings accelerated EMD's refinement process, propelling the company to market leadership in through the GP7's resounding success, with over 2,700 examples built in a five-year span.

References

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