Ingalls 4-S

The Ingalls 4-S was an experimental American locomotive built by Ingalls Shipbuilding immediately after World War II. Intended to be the first of many Ingalls-built locomotives, it wound up being the only one ever built by the company. It served on the Gulf, Mobile and Ohio Railroad (GM&O) until 1966, when it was retired; it was scrapped the following year.

Ingalls 4-S
Ingalls 4-S.jpg
Type and origin
Power typeDiesel-electric
BuilderIngalls Shipbuilding
Build dateMarch 1946
Total produced1
Gauge4 ft 8 12 in (1,435 mm)
Loco weight272,000 lb (123.4 tonnes)
Fuel capacity1,000 US gal (3,800 l; 830 imp gal)
Prime moverSuperior Engines & Compressors marine engine
Performance figures
Power output1,650 hp (1,230 kW)
OperatorsGulf, Mobile & Ohio

Design and developmentEdit

At the end of World War II, Ingalls Shipbuilding, based in Pascagoula, Mississippi, developed plans for a line of diesel-electric locomotives to serve the expected post-war market. Five models were projected; the first, and as it proved only, to be built was a prototype of the largest, the model 4-S.[1]

The design of the locomotive was considered advanced, including a "turret cab" arrangement, which improved the crew's vision.[2] The prime mover selected for the locomotive was based on a marine diesel engine built by Superior Engines & Compressors; it produced 1,650 hp (1,230 kW), of which 1,500 hp (1,120 kW) was available for the production of tractive effort by the locomotive's electric drive.[1] Provision was made for the installation of a steam generator for passenger service.[2] The locomotive was equipped with connections for multiple unit operation.[3]

Operational serviceEdit

The 4-S was tested by a number of railroads, including the Louisville and Nashville Railroad, Seaboard Air Line Railroad, and the Southern Railway among others; however no orders materialized for the type, or for any other of Ingalls' proposed locomotives.[2] The lack of orders combined with issues with the supply of components for the locomotive resulted in Ingalls electing to abandon its plans for locomotive construction;[1] the sole 4-S would be the only locomotive ever to be built by the company.[4] It was sold to the Gulf, Mobile and Ohio Railroad for US$140,000, where it received the road number 1900.[2]

The 4-S served with the GM&O, operating primarily from Mobile, Alabama, earning a reputation for toughness;[1] it once derailed, landing inverted, but was repaired and returned to service in short order.[2] In 1966, the locomotive was traded in to EMD by the railroad as partial payment for new locomotives;[1] the engine was offered to the Illinois Railway Museum for US$3,000, but the museum was unable to raise the necessary funds.[2] When no other buyers materialized,[1] the locomotive was sold to Pielet Brothers in 1967, where it was scrapped.[2]


  1. ^ a b c d e f GM&O Historical Society News, Issue #42, 1986. Via National Model Railroad Association, Pacific Coast Region. Retrieved 2012-01-17.
  2. ^ a b c d e f g Anderson, Joanne (June 5, 2011). "Ingalls-built locomotive served for 21 years". The Mississippi Press. Pascagoula, Mississippi. Retrieved 2012-01-17.
  3. ^ "The Ingalls 1500-HP. Diesel-Electric Locomotive". Diesel Power, Volume 24, 1946. Pages 588-589, 614
  4. ^ Schramm, Jeffrey W. (2010). Out of Steam: Dieselization and American Railroads, 1920-1960. Cranbury, New Jersey: Associated University Press. p. 304. ISBN 978-0-9821313-7-4.