New Zealand DB class locomotive

The D^B class was introduced to the rail network in 1965-1966 as a result of a requirement for a modern locomotive that could operate on the North Island lines that the D^A class was excluded from due to their weight and axle load.[1][2] They were ordered at the same time as the final D^A order was placed.[3][4] While these were mainly branch lines, it also applied to the East Coast Main Trunk line, particularly the section beyond Paeroa through the Karangahake and Athenree gorges until the opening of the Kaimai Tunnel in 1978.[5]

The class was virtually indistinguishable externally from the D^A class, being of the same basic design and dimensions, and wearing the same livery. They were some 13 tonnes lighter with a V8 prime as opposed to a V12, though they shared the same A1A-A1A wheel configuration and traction motors for commonality with the D^A fleet. The locomotives were supplied with cast-steel bogies manufactured by Dofasco, but these were swapped to Phase I D^A class locomotives, which were delivered with fabricated bogies, once the D^B class entered service.[4]

DBR 1254 at Westfield, Auckland.

In the late 1970s the decision was undertaken to rebuild the D^B class along similar lines to that being undertaken for the D^A class into the DC class.[5] The rebuilt D^B units were designated as DBR (R = rebuild). The work was undertaken by Clyde Engineering in Australia and involved the lowering of the short hood to improve visibility for the driver, new cabs and the installation of a new EMD 8-645 engine. Ten units were rebuilt between 1980 and 1982.[6][7]

The D^B class was employed primarily freight duties, though they did also see occasional service hauling passenger trains. As lines and bridges were upgraded, and in the case of the ECMT the Kaimai Tunnel opening, the weight advantage the locomotives had over other classes used in the North Island became less of a factor and the locomotives were operated as part of a general pool.

Initially, all DBR class locomotives were allocated to the North Island.[8] The lightweight nature of the DBR locomotives meant they were well suited to operate some South Island lines following the withdrawal of the DI and DJ class locomotives in the early 1990s.[6] The last DBR returned north from the South Island around 2007.[9]

Wellington bankers

For many years two DBR class locomotives formed the basis of a banker set out of Wellington, primarily assisting trains between Wellington and Paekakariki but also performing multiple other jobs including the Hutt Workshops shunt, work trains around the region and any unusual movements. DBRs 1199 and 1200 were the initial pair, becoming known as the "Bobsy Twins" (sp), likely a reference to the Bobbsey Twins due mainly to their consecutive numbers (a rarity under the TMS numbering system). In the early 2000s DBR1199 suffered a failure and was withdrawn from service and laid up, replaced on the banker set by DBR1267. DBR1199 was later sent to Hillside for repair and use on the Auckland SX set commuter trains, by which time the pairing of DBRs 1200 and 1267 had become known simply as "The Twins". DBR1267 was later transferred to Auckland to replace DBR1282,[12] with the Wellington banking role taken over by other locomotives.

DBR1199, Karangahake Gorge, 1980, on the former East Coast Main Trunk route

DBR 1267 at Whangarei

As of May 2017, all units have been withdrawn from service. The locomotives were withdrawn on account of being either surplus to requirements, or in poor mechanical condition. All of the DB locomotives were withdrawn by February 1989. In the early 2000s, DBRs 1199, 1239 and 1241 were withdrawn and placed into storage at Hutt Workshops.[13][14] DBR1199 was reinstated a year later for suburban trains in Auckland,[10][15] and 1239 and 1241 were scrapped at Hutt Workshops in February 2008.[16]

More withdrawals commenced in July 2013, with 1200 being the first.[17][18] A few more were laid-up over the next few months.[19][20] In February 2014, 1267, 1282 and 1295 were reinstated due to the DL class locomotives being taken out of service after samples from one locomotive tested positive for asbestos.[20][21] Withdrawals began again in May of that year when 1282 was laid up.[21][17] The rest have been withdrawn, with 1226 being the last.[22]

In June 2017, KiwiRail issued a Request for Quotation (RFQ) via the Government Electronic Tendering Service (GETS).[23][22] In August 2017, it was announced that DBRs 1254 and 1295 have been purchased by the Glenbrook Vintage Railway.[24][25] The remaining DBRs were originally sold to an locomotive/rolling stock dealer in South Africa,[25] but have now been sold to DBM Contracting.[24][26]

In August 2017, it was announced by the Glenbrook Vintage Railway that they had purchased DBRs 1254 and 1295 for eventually hauling mainline excursions.[24][25] After being stored at Hutt Workshops, the pair arrived on-site on 3 November 2017.[26] In March 2018, 1295 was repainted in the "International Orange" livery.[27][28] In May 2018, work started on overhauling 1254 for mainline certification. Both have been given GVR numbers, which are No.11 and No.12 respectively.[29] DBR 1254's restoration was completed in September 2019, and is now mainline certified.[30]