JNR Class DD16

The Class DD16 (DD16形) is a four-axle Bo-Bo wheel arrangement diesel-hydraulic locomotive type operated in Japan since 1972. A total of 65 locomotives were built between 1971 and 1975, and, one locomotive remains in service, operated by East Japan Railway Company (JR East).

Variants
A total of 65 locomotives were built between 1971 and 1975.
 * Class DD16-0: 65 locomotives built between 1971 and 1975
 * Class DD16-300: 4 locomotives converted from DD16-0 locomotives between 1979 and 1983 to become self-propelled snowplough units

Design
The Class DD16 was designed to replace the Class C12 and C56 steam locomotives on non-electrified rural lines where locomotives with a low axle load were required. The design featured an offset centre-cab arrangement using the same DML61Z diesel engine used in the Class DD51 locomotives, derated from 1000 hp to 800 hp.

History
The first two locomotives, DD16 1 and 2, were built at the Japanese National Railways (JNR) Nagano factory, and these were tested on the Koumi Line and Iida Line.

Between 1979 and 1983, four locomotives (DD16 2, 5, 4, and 13) were converted at JNR's Nagano and Matto workshops to become self-propelled snowplough units, numbered DD16 301 to 304, with the addition of bogie snowplough units on either end.

, one locomotive, DD16 11, remains in service, operated by JR East.

Preserved examples
, seven Class DD16 locomotives are preserved.
 * DD16 1: Preserved at Nagano General Rolling Stock Center in Nagano
 * DD16 7: Preserved in operational condition at Wakasa Station on the Wakasa Railway
 * DD16 15: Preserved at the Mikasa Railway Parek in Mikasa, Hokkaido
 * DD16 17: Preserved at the Otaru Museum in Otaru, Hokkaido
 * DD16 31: Preserved inside the "Memorial Ship Hakkoda" in Aomori
 * DD16 64: Preserved in Nōgata, Fukuoka
 * DD16 303: Preserved in Nagano
 * DD16 304: Preserved at the Tsuyama Railroad Educational Museum in Tsuyama, Okayama.

Classification
The DD16 classification for this locomotive type is explained below.
 * D: Diesel locomotive
 * D: Four driving axles
 * 16: Locomotive with maximum speed of 85 km/h or less