The New Zealand E class battery-electric locomotive represented the third unique type of locomotive class to be given the E classification in New Zealand. The first was the E class of nine Double Fairlie steam locomotives of 1872-75; the second E class consisted of a Mallet compound made in 1906; and as both were no longer operated by the New Zealand Railways in 1923, the classification was free to be used for a third time when the small battery-electric locomotive was delivered. This is the only time a classification has been used three times in New Zealand, though re-use happened a number of other times, arguably most notably when the A class of 1906 took the designation originally used by the A class of 1873.
| New Zealand E class (1922) | |||||||||||||||
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 E class no 1, battery-electric locomotive, between 1921-1930. A P Godber Collection, Alexander Turnbull Library.[1] | |||||||||||||||
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Introduction
editThis particular E class was ordered for service on the newly electrified Otira Tunnel section of the Midland line and was constructed in 1922.[2]
In April 1923, English Electric delivered an order of six locomotives: five EO class mainline locomotives that collected electricity from overhead wires, and E 1, a sixth small battery-electric locomotive for maintenance duties; used in the 1920s.
E 1 had a wheel arrangement of Bo-Bo-2 (including a 4-wheeled battery tender for one battery section) under the UIC classification system. The battery of 216 "Ironclad Exide" cells was of 1,670 ampere hour capacity at a five hour rate of discharge. Power at an average of 400 volts went to four 22 kW (33 kW one hour rating) self-ventilating traction motors on each axle. Four DK 30 self ventilating traction motors were each of 44 hp (33 kW), for a total tractive effort of 6,200 lbf (28 kN) and a maximum speed of 10 mph (16 km/h).[3]
It had a tractive effort of 27.5 kN at one-hour rating, and could haul 40 long tons (45 short tons; 41 t) at 8.5 mph (13.7 km/h) on the gradient of 1 in 33 (3 %) that prevailed between Arthurs Pass and Otira.[3]
Braking was by airbrakes on engine and tender, a tramway type magnetic brake between each wheel set, and a screw type handbrake.[2]
Withdrawal
editThe locomotive was written off around 1930 due to the costs involved in maintaining its batteries. Instructions were issued for any equipment that could not be re-used elsewhere from the locomotive to be dumped locally. E 1's cab can still be found alongside the track just south of Otira. The runner wagon for E 1 was stripped of its batteries and found use at Addington Workshops as a general-purpose wagon around the complex.
References
editCitations
edit- ^ "E class no 1, battery-electric locomotive, between 1921-1930". National Library of New Zealand. Retrieved 24 March 2019.
- ^ a b Churchman 1995, p. 11.
- ^ a b Palmer & Stewart 1965, p. 127.
Bibliography
edit- Churchman, Geoffrey B. (1995). Railway Electrification in Australia and New Zealand. Sydney & Wellington: IPL Books. pp. 11, 42. ISBN 0-908876-79-3.
- Pioneer Electrics: A survey of railway electrification in the South Island. A J Pickering / I D Spicer (ed.). Tramway Historical Society : Christchurch, New Zealand : 1970.
- Palmer, A. N.; Stewart, W. W. (1965). Cavalcade of New Zealand Locomotives. Wellington: A H. & A W. Reed. ISBN 978-0-207-94500-7.