| NZR AA class | |
|---|---|
| Power type | Steam |
| Builder | Baldwin Locomotive Works |
| Serial number | 41826–41835 |
| Build date | 1914 |
| Configuration | 4-6-2 |
| Length | 34 ft 9 in (10.59 m) |
| Locomotive & tender combined weight |
88.5 short tons (80.3 t) |
| Career | NZGR |
| Number in class | 10 |
| Number | 648-657 |
| First run | 1915 |
| Preserved | 0 |
| Disposition | Withdrawn |
The AA class consisted of ten steam locomotives built by Baldwin Locomotive Works in 1914 to operate on New Zealand's national rail network. Built to a similar but vastly improved design to the Q class of 1901, they had a wheel arrangement of 4-6-2 and were suited to hauling freight services in the North Island.(Originally they were to be classed QB but as they were to suppliment the A class, given their aformentioned designation.) The American built locomotives were an urgent order needed due to heavy demand with both New Zealand and British workshops unable to supply as WWI was draining resources and manpower for the war effort. All ten entered service in New Zealand in June 1915. They were worked hard for four decades being surplanted by the more powerfull "K" and "J" class families. The entire class had their boilers replaced with AB class types in the late 1930's giving the reliable locomotives more life. This soon became a blessing when they were worked hard through the next global conflict, WWII. The first withdrawals occurred in December 1955, when six were taken out of service with their boilers returned to the AB class boiler repair pool. The remaining four continued to operate until February 1957. None are preserved.
