WIRE WIZARDRY

Evening Post, Volume CVI, Issue 27, 1 August 1923, Page 9

WIRE WIZARDRY

SMOKELESS TRAIN

ELECTRICITY FOR BOTTLE-NECKS

On 25th August, 1920, the New Zealand Government arranged a contract with the English Electric Company for electrification, the price being approximately £350,000. The contract included the electrification of thirteen miles of track, as follows: Tunnel, 5^ miles; from Otira end of tunnel to Otira station, 3 miles j station sidings at both, ends, 5 miles. "The contract," write* a contributor, "also included the electrical equipment of a coal-aad-steam generating station of 4000 horsa-power capacity at Otiva: the supply of : six electric locomotives (which, will draw the ordinary rolling stock of the Government railways); the

electric lighting of the tunnel; and the equipment of the necessary workshops at Otira. Otira is the headquarters township of the electrified line, Arthur's Pass station (on the Bealey side) being secondary, so far as tho control of the tunnel is. concerned. OTIRA POWER-HOUSE. "All the important departments, power-house, locomotives, balteries, signalling plant, etc., are located at Otira* and Canterbury people and those from other parts of the Dominion who see the West Coast township, for the first time are in 'for a surprise. The attention of visitors to Otira, is first held by the. imposing • power-house, a very fine t structure with modern equipment, two

steam turbines of 2000 horse-power, 160 steam pressure, 29-inch vacuum, and 3000 revolutions per minute are geared down by a double helical single reduction geaT, to drive the generator of 1200 kilowatts and 1650 volts at a speed of 450 revolutions per minute. There are three marine typo Babcock and Wilcox boilers I i with, induced draught fans. "The Otira tunnel is the first section of railway to be electrified in New Zealand, and therefore possesses additional importanoe from the viewpoint of progress. The rails used on the main line of the electrified section weigh 1001b to the yard,' compared with 701b to the yard on ordinary main lines of the Government railways. The heavy braking . on the 1 in 33 grade, and better electrical conductivity are reasons for the extra ■weight. The electric locomotives are of the latest type anc\ are calculated to carry out easily all the demands made upon them. Each main line locomotive, weighing 50 tons, is of 680 horse-power' operated at 1500 volts. Freight trains will be drawn by two locomotives and passengers trains by. one. A battery locomotive, known as 'Jumbo,' will be used for the inspection of overhead work and for shunting. 'Jumbo' is driven by batteries independent of the,main source of power. The power for the auxiliary plant is secured from Goat Creek, 626 feet above the power-house, generatinz 200 horse-power. i "The electric signal system at Otira is the very latest idea, and is similar to that used on the London tubes. The claim is made for the Otira system that it absolutely prevents accidents Mr Evan Parry, chief engineer of the English Electric Company, is satisfied with the work and Mr. L. Birks, Chief Electrical Engineer to the New Zealand Government, has pronounced it a first class job. The depot for the steam locomotives in use between Otira and Greymouth, in addition to the usual sheds, is equipped with a modern coal stage with pneumatic loading crane • also a sand-house and other accessories'" The electric tTain will probably take less than twenty minutes to go through the s^-mile tunnel. 6 IMPORTANT BRAKING. From another source, an article in 'Board and Council," it is gathered that the main line electric locomotives each weighing 50 tons, are constructed to run at 18 miles an hour on the up gradient (1 in 33) with a fully-loaded 4in The resistances are designed to limit the speed on the down gradient to 26 miles an hour when two locomotives are holding a passenger train of 200 tons. On a gradient of 1 in 33, brake gear must be absolutely reliable, and "the locomotives are, therefore, fitted with four braßes the rheoetfttic brake, the iWeitinghouje

[ automatic air brake, the Westinghouse straight air brake, and the hand brake. "The rheostatic brake was adopted in preference to the regenerative brake, because the powerhouse supplies the railway load only, and therefore there are occasions when there would be no load to absorb .the regenerated energy. The rheostatic brake also renders the locomotive independent of the trolley voltage . . The locomotives are fitted with hand-operated and air-operated sanding gear. A large standby battery is carried to provide energy for the control gear, and compressor motor at 120 volts. Its capacity is sufficient to enable the locomotive to make a complete round

trip. In the event of the 1600 volt supply tailing, the battery supply enables the driver to use the rheostatic brake as well as the air brake, and thus furnishes an additional factor of safety." At present only five main line locomotives are required, but it is anticipated that, as the traffi increases, eight main line locomotives will eventually be required for the working of the electrified line. ••■-•: ■ THE PANTAGRAPHS. _ The type of main line locomotive to be used is shown in the illustration. The locomotive has four D.K. motors, each of which "develops 170 h.p. at the tread ol the wheel at the one-hour rating-. The corresponding speed at 1500 line volts is 18 miles per hour. The motors are wound for 750 volts, and are connected in permanent series. The tractive effort is 14,2001b at the one-hour rating. The locomotive bogies are articulated so that none of the tractive force of the motor is taken through the underframe. an important provision when it, is remembered that the tractive force will be considerable when the trains are doubleheaded." It may be added here that while the voltage of the Otira electric locomotives is 1500 the voltage of the Wellington elec- i tncal tramway service is 500-550 The Otira voltage of 1500 is the same as the voltage of the electrical suburban railway system operated at Melbourne by : the Victorian Railway Commissioners, so there is some prospect of having a uniform system and voltage throughout Australia and New Zealand. To a layman used to the businesslike outline and forceful lines of a steam engine, the illustration may come as a surprise, perhaps as a disappointment. To the layman s eye there is none of the outward visible sign of power. There •is no smoke to signify internal force, which signifies energy. But the energy is there. This "mere car" is alive with motive force. The most noticeable thing in the illustration, to a layman's eye, is the overgear, which somehow gives the impression that a tame tramcar ha 6 been'attacked from above by something that fell out of the Book of Euclid. It seems that the composite rectangles are called pantagraphs. They take the current from the electrical power lines overhead. These two pantagraphs are floated on springs and are pressed against the energy-giv-ing lines by compressed air. IMPROVING WEAK LINKS. „^!? c position that the South Island Midland Railway (Canterbury to WestGoast finds itself in with regard to OUra tunnel may be compared with the problem that American railway companies have found in their Rocky Mountain crossings. Mr Evan Parry, the wellknown hydro-elcctnc engineer, who was formerly Chief Electrical Engineer to the New Zealand Government, and who is now of the English Electric Company contractors for Otira tunnel electrinca- ! tion), h as pomted out that the Chicago, Milwaukee and St. Paul R ai i wav (£f m Fm™ fr Dd that the Bo^y MountSSs imposed a severe restriction upon the tofflc-carrj-mg and earning capSy of tha whole of this company's system from Seattle, to Chicago, although the mountn ?h T7 1 1S ™Ut ahorfc 'm P^Portion to tha whole. The company applied electric workmtr to the Rocky Mountain division, first over a distance of $0 miles, and afterwards to the Cascade division a dastance of 220 miles, which has enabled the comany to double its traffic not only on the mountain division, wnr/^^ h°Ut -5 16 srßtem- !« the words of the president, the officials Jiavr> "forgotten" that the Rocky Mountain exist m regard to their "influence on the traffic.

The Otira tunnel crossing of the Southern Alps presents a similar problem MMI ?^ w.,Zealan^, Government on the Midland Eaihvay. The mountain division is only short; but the capacity of a bottle in influx and efflux, is the capacity of its narrowest part, Just as the greatest strength of a chain is in its weakest link. Where, as at Otira, the grade is too severe for a steam locomotive to work to the best advantage, and where I a limit is thus placed on the movement of traffic, the electrifying o f a comparatively short section may double the carrvme capacity of the whole of the railway. WEAK LINKS NEARER HOME. Mr. Parry writes: "Mountain divisions generally present very favourable conditions for electric traction, an iteam locomotives reach the limit of their capacity

very quickly on grade, and impose limitations on the movement of traffic. It has been proven that the application of electricity to haulage on sections where the grades are severe increases the carrying capacity of that section from two to three times the maximum capacity possible with steam haulage, according to the nature of the grades and the number of tunnels, etc. . . . The same reaaoning applies to the division from Springheld to -lackson's on the Midland Railway Irom Taumarunui to Waimarino on the North Island Main Trunk, and in a lesser degree to the section between Wellington and Paekakariki. In these cases the traffic-earning capacity of the whole system, of which they form a, Part, is substantially increased at the cost of electrifying a portion only where thegradients are severe." Note carefully Mr. Parry's words: ,£™ m Springfield to Jackson's on the Midland Railway." The present electrification, from Otira to Arthur's Pass station is only a portion of Springfield to Jackeons; the latter comprises the whole mountain section, 62 miles, whereas the length of the present electrified section is only 8 miles (plus 5 miles of sidings). But Mr. Parry says that the greater application i B the logical outcome of the smaller one. When Mr. Parry, then acting for the New Zealand Government, went into this electrification question, he prepared particulars covering the whole mountain section; but, he adds, "it was decided finally to limit the application of electric working to the Otira-Arthur's Pass section as a first instalment, as it was desirable to keep down capital expenditure, and furthermore, whilst several local sources of power were available which were adequate to the needs of the Otira-Arthur's

Pass eection, the electrification of the whole line depended upon an extension of the Lake Coleridge power plant. Besides this, inasmuch as electric working on the New Zealand railways is rather of an experiment, it was a good principle to experiment on a small scale, and to familiarise and to educate a trained staff of electric workers." . SAVING BLACK DIAMONDS. If strictly economic reasons alone governed the question of applying electricity to railways, its application might be limited to suburban lines and mountain divisions and tunnels, i where it is needed to get additional traffic through. But sometimes strategic reasons influence the application of electricity; and sometimes the desire to conserve coal fuel (a wasting asset) operates. On this point Mr. Parry writes: r< There is another reason, for "electrification of railways which has a national aspect, by the saving in coal, which seems more difficult to get as time goes on. Taking the division of Springfield ■to Jackson's as an example, it would require 11,000 to 12,000 tons of coal per annum to maintain by steam locomotive the service specified—viz., 1000 tons per day from west to east, 700 tons per day from east to west, together with one passenger train each way per day. This coal has to be hauled backward and forward, up and down steep gradients, a*.the cost of a further quantity of coal, and additional rolling, stock has to be provided." Unlike; the black diamonds, the "white diamonds" transport themselves'

and are inexhaustible. Nor do the naturally-replenished water supplies go on strike.