8/14/2023 0 Comments Timber framer iron mine![]() The roadway is thus partially cleared so as to establish ventilation and to remove the trapped men. Temporary props with thick and wide sole plate and top lids are erected on the debris to support the roof temporarily for safety of debris-clearing majdoors. The debris of roof fall is then removed by workers and packed up in the nearby galleries but where speed is essential, it may be packed along the sides of the haulage road itself. Standing at the safe place near the cogs, the loose or hanging pieces in the roof are dressed down by the timber men with a bunton. Cogs are erected at the junction as shown at d, and bars placed over the cogs. 9,12 sets of props and bars are erected at a, b, c after dressing loose roof rock and the approaches to the fall made safe. In all such cases where the roof fall has to be cleared up work must always be done from a safe place and as the debris is cleared, supports should be set so that the place out bye is always free from danger. During extraction of stocks, wooden chocks are provided in the split galleries and later on the clamps are recovered completely for re-use. One of its applications is to support the split galleries in depillaring areas in thick seams and extract the floor coal, heightening the galleries upto 5 m. The support stands the effects of blasting and the freshly exposed roof is supported in a short time after exposure. The clamps can be easily recovered and used again for several times. The complete operation of setting the support is completed in 15-20 minutes for each cross bar. The cross bar is placed in position over the two brackets and tightened against the roof with wooden wedges. rods of each clamp are inserted into the holes drilled in the coal pillar. ![]() and 175 mm apart, are provided for two m.s. bracket is welded as a seat for the wooden cross bar and in the angle iron two holes, 35 mm. Each clamp consists of an angle iron frame to which semicircular m.s. ![]() This support consists of a pair of clamps of mild steel on which a cross bar is placed to support the roof. For quick setting of the cross bars, the" manual cutting of holes in the coal pillars is eliminated by drilling holes with the usual coal drills and a support, known as safari support, is installed to support the roof. Therefore the supports lag much behind the working face. This is time-Consuming and the whole operation of fixing one cross bar by this method takes about 2-2 ½ hours. For fixing these cross bars, holes are to be made in the coal pillars manually by crowbar. The conventional method of supporting galleries in coal mines is by means of wooden cross bars. ![]()
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