The Cine Technician (1953-1956)

38 THE CINE-TECHNICIAN March-April, 1952 PROBLEMS of FILMING in COAL MINES by RON BICKER SINCE the war there has been a great increase in the amount of Cinematography carried out in Coal Mines. Technical Research Units have been shooting underground for years, but the working conditions and technical limitations surprise most Commercial Units when they get their first underground assignment. The most obvious problem is that of working at close quarters to a fairly dangerous industrial operation; at all main points in a pit there is complex machinery for cutting coal, conveying it from the coal-face and transporting it by haulage-ways for considerable distances. No unnecessary space is left and a certain amount of " pit sense " is required to keep out of harm's way. Into this type of location one must introduce the minimum amount of equipment and cause the least possible interference with production. Having accepted considerable reductions in set-up, due to lack of working space, one is still up against the problem of slightly " un-photogenic " subjects; coal which does not always sparkle, black machinery, and miners with black faces. What must clearly be aimed at is " effect lighting " of the kind produced by the miners' cap-lamps and normal roof lights. But here is a snag. The use of standard studio lighting gear is restricted to " naked-light " pits; in the remaining 90 per cent — which includes nearly all the large pits — special flameproof lamps must be used. These lamps are essentially floodlamps designed for normal illumination in oil refineries and other places where the fire risk is high. For their 500 watt output they are extremely heavy, so that they are normally used on the ground oi else lashed securely to overhead girders. Their light output takes the form of a " hot spot " with a large area of " scatter." Hydraulic Pit Props Still by Suschtt sky the useful output being considerably less than that of a " pup." A complete set consists of 12 lamps with two heavy distributor boxes. In practice it is generally possible to get something more than floodlighting from these Units by hiding or niggering the back-lights, but there is often no room to conceal them and most of them have to be used frontally. The lamps are fed from standard underground transformer gear, often through considerable runs of armoured cable. These cable runs, as well as the normal demands of heavy machinery, tend to cause reduced and fluctuating voltage, resulting in an extremely low level of lighting. An interesting experiment was carried out recently using only the normal light fittings in a 400 yd. long colliery tunnel. The camera was turned over at 4 frames per second at F.2 and tracked along the Coal Conveyor. For normal 24 F.P.S. shooting, however, mid and close shots are always more effective than the longer shots which are bound to be underlit. The camera generally used is the Newman Sinclair. Until non-flam stock was introduced this was the only camera which conformed with safety regulations, and in any case the use of an electrically driven camera would be restricted. We usually protect the lens against dust and spray by using a clear glass optical flat, and trouble is often experienced with " misting-up " in humid conditions. In conclusion it can be said that a better photographic effect of underground conditions would be obtained in " surface mock-ups," but because of the complex lay-out of a modern mine and the need to show authentic conditions, it is generally essential to shoot on the spot.