ELECTRIFICATION WORK PROCEEDS WITH EXPEDITION.

Star (Christchurch), Issue 18451, 30 April 1928, Page 10

ELECTRIFICATION WORK PROCEEDS WITH EXPEDITION.

CHANGE OVER ON PORT - LINE IS PREDICTED BY END OF YEAR.

(Special to the "Star.") WELLINGTON. April 28. The signal and electrical_ branch _of the Railway Department is carrying out two extensive works in Christchurch, and is making progress well in line with the programme. Work in connection with the electrification of the Lyttelton tunnel and the section of railway between the port and the city has gone ahead with such expedition that it is easy to predict that before the end of this year, electric locomotives will be hauling the traffic. A comprehensive survey of the work in hand was obtained from the head of the signal and electrical branch of the service. Work in the tunnel is about half a mile inside. It has been found necessary to cut away the roof in many places to give proper clearance for the contact wires, but the worst of these places have been dealt with, and the wiring is going on up to programme time. The rock of the tunnel —much of it is unlined—is very hard, but compressed air drills make it easy to carry out the borings. A compressor is installed at the Heathcote end of the tunnel. To fix the ring bolts suspending the wiring, air drills make the holes in the rock and compressed air at SOlhs to the square inch drives cement through a cement gun, making a very solid job of the sealing in of these bolts. The Public Works Department’s programme in connection with electrification involves the provision of 11,000 volt power, and the erection of a sub-station, which is proceeding according to time-table. Six electric locomotives needed for the work of the electrified section are being built in England, and it is expected that the manufacturer will be able to make delivery before the end of the year, as stipulated in the contract. These locomotives are to be housed in a portion of the old engine shed at Linwood, which is now being altered for the purpose, two roads in this shed being electrified, and the space boxed off from that required for the steam locomotives. Electrification of the tracks involves bonding of the rails for the return current, and this work will shortly be put in hand. No track allegations are needed, and the task is simple. It is proposed to electrify the track at the port to the point at which trains for the ferry wharf have to be taken before being backed to the wharf, and it is not intended to carry the electric overhead system to the wharf itself. At the Christchurch end the electric system will run to Colombo Street, and will include a good many of the yard tracks. With the exception of four, all the poles for the overhead equipment are erected, and the Department is waiting for the completion of work in the tunnel to release the air compressor as some concrete has to be drilled out at Lyttelton near the wharves, before the final poles can be placed in position. Cross wires for the cross catenaries are being prepared for hanging, and the insulators arrived on a recent overseas steamer. As soon as they are delivered at Lyttelton, the department will commence to run out the actual power wires, which are suspended from the catenaries. Some trial lengths will be run out in a few days’ time. The erection of the overhead equipment involves a good deal of careful planning and thorough workmanship. While the catenary wires, from which the power wires are suspended, will show a graceful droop between the suspension points, the trolly wire itself will be kept perfectly horizontal. The stresses have been worked out beforehand, strong springs will be fitted to the catenaries so as to maintain the required strain, and the calculated tension will be applied by dynometer winches. WORKSHOP ELECTRIFICATION. All the machinery at Addington Workshops is being provided with electrical drive, which will ultimately take 3500 horse power. The new sub-station required is in course of erection, and nearly all the underground armoured cables to distribute the power to the motors have been laid. Practicaliy ail the machinery will be driven by independent motors. This power scheme has necessitated much skilful planning, for three kinds of current are needed! The three-phase is used for ordinary workshop operation, continuous current at 220 volts is wanted for cranes and other plant requiring close adjustment, and single-phase for rivet heating, tyre work, and welding.