PREVENTION OF FIRES

Te Awamutu Courier, Volume 75, Issue 6441, 3 November 1947, Page 7

PREVENTION OF FIRES

SPARK ARRESTORS FOR LOCOMOTIVES NEW APPARATUS DEVISED A device that could possibly have some application to railway engines, which have in the past proved a frequent cause of fires in dry areas, has recently been tested before officials of sawmilling companies and the State Forest ServiceThe frequency with which forest fires have been started by sparks emitted from bush locomotives and haulers has caused the Forest Service and the sawmilling industry much concern, and various types of spark arrestors have been devised and tried out from time to time. None of these, however, has been completely successful—if the apparatus prevented the emission of sparks it usually failed in some other respect, fine screens became blocked, for instance, and interfered with draught, with the result that the engine driver became impatient anad enlarged the holes in the screen. A new type of spark arresFor has recently been devised by Mr T. Wai-' len, of Mangapehi, which, it is hoped, will overcome the defects of the existing types. There are no screens ' or meshes incorporated in this new design. The whole appliance is fitted inside the smoke chamber in front of the boiler. Briefly it- comprises a circular drum approximately 27 inches in diameter by 5 inches deep, the drum being fitted with vanes set at an angle and radiating from centre to rim like the spokes of a wheel. Through the hub or centre passes the steam exhaust from the cylinders. Above this drum is a second circular drum topped with a cone shaped hood leading up the locomotive funnel. As the smoke from the boiler tubes is drawn up through the inclined vanes of the lower drum, it is given a rotary movement which tends to throw embers and partially burned material to the perimeter of the upper drum where they remain (still circulating around inside the drum) until completely burned up or pulverised into dust. A demonstration of this spark ! arrester was made, at Mangapehi rec- ' ently before officials of sawmilling ; companies and of the State Forest i Service. This demonstration took I place on a dark night when any ’ spark, no matter how small, would i show iip distinctly. Two Climax ’ geared locomotives were used, one! fitted with the new spark arrester and • one with no spark arrester. The fuel ! used in the test was a mixture of ; slab wood and soft coal and care was | taken to ensure that the method- of firing, steam pressure, etc. would be identical in the two locomotives. The two engines were -coupled together in “tug-of-war” fashion, thus ensuring that they were working to ’the limit of their power and each exerting equal effort. A The results were moswspectaculai and striking. Whilst the locomotive with no spark arrester emitted sparks like a Roman candle, large numbers i of red-hot embers up to half an inch ' or more in size, many of which con- ' tinned to glow for some time after i landing on the ground, the engine 1 fitted with the arrester emitted prac- i tically no sparks at all—the odd ! small spark or so which did appear ’ was apparently light fluffy material only, which was completely extingu- i ished long before it reached the j ground. Drivers who have operated the I locomotive fitted with this spark j arrester stated that there is no loss | of power. There are no screens or j small, apertures to block and the ! device is self-cleaning. Additional ; locomotives are being fitted with this i new type of spark arrestor and the ; operation of these will be watched 1 throughout the summer, but presentj indications are that this spark arres- ' ter will do much to minimise the fire | danger from steam operated bush ! haulers or locomotives.