NZR DSB class

In 1950, NZR placed an order for 25 D^SB shunting locomotives.^[1] They were built by the Drewry Car Co. between 1954 and 1956.^[1] The first three D^SB class locomotives were commissioned in August 1954. The D^SB are a larger and more powerful locomotive than the D^S and D^SA classes and were used all over New Zealand. A second batch of three locomotives built by Mitsubishi Heavy Industries was introduced in 1967.^[2] Included with the three Mitsubishi DSB class were two additional locomotives for the Ohai Railway Board at Ohai, Southland.^{[citation needed]}

The Drewry type B-2 had a cover-plate over the locomotive's jackshaft to prevent staff from being caught by the jackshaft while riding on the cab steps.

By the end of their lives, 12 DSBs were repainted in the "International Orange" livery.

In line with NZR's policy of rationalising locomotive classes, the DSB class was entirely withdrawn by the end of the 1980s.^[2]

As of July 2014 only one DSB class has been preserved, DSB313 was purchased in January 1991 by the Mainline Steam Heritage Trust for shunting at their Parnell depot.^[3] However, both of the Ohai Railway Board's DSB-class equivalents No.1 and No.2 have been preserved, No.1 at Ocean Beach Railway, Dunedin, and No.2 at Steam Incorporated, Paekakariki. ^{[citation needed]}