NZR AA class

New Zealand 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Disposition	Withdrawn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 New Zealand A^A class consisted of ten steam locomotives built by Baldwin Locomotive Works in 1914 to operate on New Zealand's national rail network.

Introduction

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 Q^B but as they were to supplement the A class, given their aforementioned designation.) The United States built locomotives were an urgent order needed due to heavy demand with both New Zealand and British workshops unable to supply as the First World World was draining resources and manpower for the war effort. All ten entered service in New Zealand in June 1915.

Service

They were worked hard for four decades being supplanted by the more powerful "K" and "J" class families. The entire class had their boilers replaced with A^B class types in the late 1930s giving the reliable locomotives more life. This soon became a blessing when they were worked hard through the Second World War. The first withdrawals occurred in December 1955, when six were taken out of service with their boilers returned to the A^B class boiler repair pool. The remaining four continued to operate until February 1957. None are preserved.

External links

• Baldwin Steam Trust - New Zealand locomotives built by Baldwin, including A^A class statistics
• Plan of an A^A class locomotive by Derek Brown