NZR EC class

New Zealand EC class

Sole preserved member of the class, EC 7 stands at Moorhouse Station on the Ferrymead Railway during the Easter 2008 railfan event
Type and origin
Power type Electric
Builder English Electric, United Kingdom
Build date 1928
Specifications
UIC class Bo-Bo
Gauge 3 ft 6 in (1,067 mm)
Length 12 metres (39 ft 4 in)
Adhesive weight 50 tonnes (49 long tons; 55 short tons)
Loco weight 50 tonnes (49 long tons; 55 short tons)
Electric system(s) 1500 V DC overhead lines
Current collection Pantograph
Traction motors 4
Performance figures
Maximum speed 85 km/h (53 mph)
Power output 888 kW (1,191 hp)
Career
Operators New Zealand Railways, Lyttelton Line
Class EC
Number in class 6
Numbers 7 - 12
Locale Christchurch - Lyttelton
First run 1929-02-14
Last run 1970-09-18
Disposition Withdrawn; 1 preserved

The New Zealand EC class was a class of electric locomotive used in Christchurch, New Zealand. They replaced steam locomotives on trains through the Lyttelton rail tunnel between Lyttelton and Christchurch.

Introduction

Since its opening in 1867, the Christchurch to Lyttelton line had become extremely busy with both suburban and goods trains passing through the 2.6 km (1.6 mi) Lyttelton Tunnel, which had been opened in 1867. However, smoke accumulating in the tunnel from each successive train became a nuisance for train crews and passengers travelling through the tunnel. Although trials were conducted in 1909 using steam locomotive WF 436 which had been converted to oil firing, the cost of oil alone meant that no further work was done.

In 1925, the English consultancy of Merz & McLellan was commissioned by then Minister of Railways, Gordon Coates, to report on electrfying the suburban networks in Auckland, Wellington, Christchurch and Dunedin. The report, released in August 1925, recommended that of the Christchurch system, only the 10 km (6.2 mi) Lyttelton line warranted electrification due to the volume of traffic and the Lyttelton tunnel. To operate the line, Merz & McLellan recommended purchasing five electric locomotives to haul all trains on this line, and that electric-multiple units would not be necessary.[1] The new electrification should be the same 1.5 kV DC as used at Otira and later in Wellington.

Accordingly, six EC class electric locomotives were purchased from English Electric exclusively for this work in 1928. They were similar in many respects to the earlier 1923 EO class as delivered by EE, but had longer bogies, higher gearing for a higher top speed of 85 km/h (53 mph), and more powerful motors. Initially classified in the E class, the later 'C' designation indicated these locomotives were to be allocated to Christchurch, as opposed to the EO class which was allocated to Otira.

In service

The EC class handled all duties from Christchurch to Lyttelton. They were capable of handling 600-long-ton (610 t; 670-short-ton) freight trains and the famous Boat Train, known colloquially as the 'Jackaroo', which regularly loaded up to 400 long tons (410 t; 450 short tons).[2] Early problems with motor flashover and armature shaft fractures during transition from series to parallel meant that the parallel connections were removed, halving the voltage to the motors and reducing the running speed to 42km/h.[3]

Withdrawal

In 1970, the EC class was reaching the end of its economic working life. Due to the locomotive changeover for such a short section being costly, and with drainage work going on in the vicinity of the Woolston sub-station, it was decided to reduce the losses made on this section and at the same time make it easier for the drainage work to proceed by withdrawing the electric locomotives. Diesel locomotives would be able to handle all trains through the tunnel.

All six locomotives were written off in September 1970, with the last in service being EC 9, which hauled the last electric train over this line on Friday 18 September. Five of the locomotives were then scrapped while one was put aside for the Ferrymead-based Tramway Historical Society.

Preservation

Class leader EC 7 along with EO 3 was donated to the Tramway Historical Society upon withdrawal. Stored in the Linwood locomotive depot, the locomotive was transported to Ferrymead by road in 1972, where it nearly ran away during the unloading operation. The two electric locomotives were stored by the tramway section until 1977 when the THS handed the two locomotives over to the Ferrymead Railway-based Electric Traction Group. Both locomotives were shifted onto the railway tracks using electrical leads off the 600V DC tramway overhead and several tracksets, which were moved with the locomotives to the railway. In 1978, part of the Ferrymead line at Moorhouse station was fitted with overhead catenary and in 1980, some test runs were done with EC 7 at 600V using the tramway power supply. This led to the acquisition of three mercury-arc rectifiers to power the railway, as well as the trams and trolley-buses.

With construction of a substation able to supply the railway, tramway and trolley-buses was subsequently commenced and in November 1988, it was officially opened with trains hauled by EC 7 on the electrified section of the Railway. EC 7 is periodically operated at the Park, usually double-heading with EO 3. This is due to the lack of electrification on the Moorhouse station loop, which does not allow one locomotive to head the train on its own.

References

  1. ↑ Churchman, Geoffrey Basil, Railway Electrification in Australia and New Zealand, IPL, Wellington, 1993. pp. 16-19.
  2. ↑ Palmer, A. N. and Stewart, W. W., Cavalcade of New Zealand Locomotives, NZR&LS, Wellington, 1956, second ed. 1965. p. 129.
  3. ↑ Churchman, p. 19.

Further reading

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