A FAMOUS ENGINE.

Press, Volume LV, Issue 16426, 21 January 1919, Page 8

A FAMOUS ENGINE.

—I NEW ZEALAND BIG Ab. j A big compliment to New Zealand's | talent and skill is given in "Engineer- j (Lng" (Lojufrn) of November 22nd, 1918. with a three-page feature article on *bhe powerful Ab locomotive designed here a few years .ago* . 1 11 dition to diagrams embodied in the article,- there is a special art-paper inset wifch drawings which bring out the points of the Dominion's champion engine, which won fame by beating easily the best achievements of the big Baldwins. The article is concerned mainly with locomotive designing for 3ft Gin gauge railways—the New .Zealand standard. This country required a special engine, and- evolved one which proved, far superior to t&e best of the imported engines. The Ab is New-Zealand all the way., workmanship—a . New Zealand, idea) drafted here and worked out in the Adding ton Railways Workshops. Here are • a few extracts from . "Engineering," setting out the prowess of the "The first engine built of the* Ab type was tested on .the .express run from Christchurch to Timaru against the best compound available. Each engine hauled the train out and home for five consecutive days, doing 200 miles per day, and the result of tb6 1000-mile test was decidedly in favour of the new engine. The detailed record shows the saving as 20 per cent, in water and 33 per cent, in coal, and this includes coal used in making up the fire each morning and during the two hours' stand over at Timaru. "The train is now being run by the new engines exclusively, and the saving in coal and water is being realised steadily. Part of the saving is undoubtedly due to the boiler, which is easily the best steaming boiler seen in a locomotive in New Zealand, but of this saving part is due again to super-heating. However, without indicator diagrams and tests made on a testing plant under exact conditions it is extremely difficult to apportion tne figures with any degree of accuracy. The broad facts remain that this superheated simple engine saves about 3C per - cent, of coal over the saturated compounds, which again are quite 25 per cent, better than the saturated Baldwin simples they superseded on this run in 1907. "The saving in coal effected b; these new engines was not the onl; advantage. The compounds, whil capable of hauling 15 cars on the ex press run under favourable conditions could be regularly trusted with onl: 14. The capabilities of the new en gine in this respect could not be full; ascertained, as traffic restrictions fi: the maximum load at 20 cars, whicJ load the new engines take with ease and make up a good deal of time whei necessary. Probably the finest per formance ever recorded on the 3ft 6ii gauge was accomplished on Januar; 29th, 1916, when a train of 20 heavily loaded cars was brought from Timan to Christchurch under difficult condi tions. Traffic delays inseparable fror holiday traffic were accentuated by i hot-box oil a car, so that 22 minute had to be made up. This reduced th actual running time for the 100 mile to 147 minutes, but, despite a hear, north-west gale, a train weighing 42 tons behind the carried on & axles, and over 950 ft in length, wa brought to Christchurch on time, al though a signal stop at the platfora made actual arrival four minutes late Allowing two minutes for each star and stop, the average running speet works out on this occasion at 46 milei per hour, a notable performance for ai engine with 64-inch drivers and onl] 30 tons adhesive weight, with a trail of 420 tons. "The success of the new engines oi this run, particularly the abolition o! double heading, caused the building ol 20 of these engines to be pushed on and some were brought to the Nortl Island, and they now work the Mail Trunk express between "Wellington an<J Taihape, and between Auckland anc Taumarunui. "These engines are great favouritee with the crews, and have given sucL satisfaction in general use that thej are now looked on as standard engines for both passenger and goods services for main-line runs, and will be the only tender engines built till such time as heavier axle loads are allowed."