the from Tinwald to Washdyke at . Anecdotal comment around the performance of the JA on the South Island Limited during the late 1960s speaks of the speedometer reading in excess of and the train moving away rapidly from the traffic on State Highway 1 adjacent to the railway. Rail writer David Leitch believed JA drivers' accounts of running as accurate. Additional support comes from an official source, the 1966 Encyclopaedia of New Zealand, which states "The speedy and graceful "JA" has demonstrated its remarkable performance in express service on the level plains of Canterbury, and on occasions has attained speeds in excess of 70 miles an hour." The official NZR speed record of was set by a Vulcan RM class railcar on a delivery trial run in 1940. Withdrawal and disposal The first of the class, JA 1249 and 1272 were not withdrawn until March 1968, in distinct contrast to the types J, JB and North British JA cousins. In 1966, 12 JA class members (and four J class) received a full overhaul, six in 1967 and two in 1968. Use of steam on freight trains on the East Coast of the South Island finished in March 1969, and 15 JAs and the three Js rebuilt with North Island JA tenders and trailing engine bogies were maintained for service. JA 1267 was the last steam engine given a full overhaul by NZR in November 1968. It appears this last full overhaul involved extensive use of parts from JA 1268 and included fitting a different boiler, (both the last two New Zealand and Southland JA 1273 and 1274 had their low mileage boilers transferred to other JA in 1967-68, and ran to 1971 with older JA boilers, (1274 being in static preservation at Dunedin station in 1975) and with the last three Js provided one of the last high-speed steam-hauled passenger services in the world, between Christchurch and Oamaru. The JA class lasted in front-line duty until the end of steam in New Zealand; the South Island Limited was then worked by steam locomotives until replaced by the diesel-hauled Southerner in November 1970. It was also planned to dieselise the overnight Friday and Sunday express with surplus steam heat vans when the North Island Limited was replaced by the Silver Star, but late delivery of the new train from Japan meant the services were steam-hauled for another year until 26