ALCO DL-109

ALCO DL-109

An Alco DL-109 pictured in a publicity postcard for the NYC-SOU-SAL Florida Sunbeam

Type and origin Power type Diesel-electric Builder American Locomotive Company (ALCO) Model DL-109 Build date December 1939 — April 1945 Total produced 74 Cab units +4 Booster units

Specifications Configuration: ​  • AAR A1A-A1A Gauge 4 ft 8 1⁄2 in (1,435 mm) standard gauge Wheel diameter 40 in (1,016 mm) Minimum curve 21° (274.37 ft or 83.63 m) Wheelbase 58 ft 4 in (17.78 m) Length 74 ft 6 1⁄2 in (22.72 m) Width 10 ft 6 in (3.20 m) Height 14 ft 4 in (4.37 m) Loco weight 337,000 lb (153,000 kg) Fuel capacity 1,200 US gal (4,500 L; 1,000 imp gal) Prime mover (2) ALCO 539T RPM range 740 rpm max Engine type (2) Straight-6 Four-stroke diesel Aspiration Turbocharger Generator (2) GE GT-557 Traction motors (4) GE 730 or (4) GE 726 Cylinders 6 Cylinder size 12 in × 13 in (305 mm × 330 mm) Loco brake Straight air Train brakes Air

Performance figures Power output 2,000 hp (1,490 kW) Tractive effort 56,250 lb (25,510 kg)

Career Locale U.S.A. Disposition Scrapped

The ALCO DL-109 is one of six models of A1A-A1A Diesel locomotives built to haul passenger trains by the American Locomotive Company (ALCO) between December, 1939 and April, 1945 ("DL" stands for Diesel Locomotive). They were of a cab unit design, and both cab-equipped lead A units DL-103b, DL-105, DL-107, DL-109 and cabless booster B units DL-108, DL-110 models were built. The units were styled by noted industrial designer Otto Kuhler, who incorporated into his characteristic cab (US Patent D121,219) the trademark three-piece windshield design. A total of 74 cab units and four cabless booster units were built.

All models developed 2,000 hp (1,490 kW). The first unit built as ALCO Specification DL-103b was 4 ft 5 in (1.35 m) longer than the other cab units, and became Chicago, Rock Island and Pacific Railroad #624. The DL-103b had the two radiator sections positioned together at the end of the carbody, while all other units had a split radiator arrangement with one placed at the back of the unit and one situated in the middle. The DL-103b was built with twin 6-cylinder ALCO 538T Diesel engines as prime movers; all other DLs in this series were built with the newer twin 6-cylinder ALCO 539T Diesel engines. The DL-103b also had all-electric driven accessories, while the later models had belt-driven accessories. The differences between all subsequent models were minor. The DL-105s went to the Rock Island as #622 and GM&O #270-271. All other early customers got DL-107 cab units and DL-108 boosters until the first DL-109 was delivered to the New Haven. During the war, the Gulf, Mobile & Ohio and Southern Railway bought DL109s and the Southern bought the only DL-110. It is not known whether this is because the model was a significant improvement, was the model approved for wartime production, or both.