October 9, 1914 THE COLLIERY GUARDIAN. 769 Upton, Staffs. Fig. 2.—Double Deck Pit Cages. 14 cwt. In addition, three similar cages of half the size have been made for the same colliery, and all of them are working in conjunction with detaching hooks of the type already mentioned. The cage illustrated in fig. 5 is an example of the forged bar type, and was built for a large Yorkshire colliery. The cage is from the colliery company’s designs, and is unusually heavy and strong. The cage bars are somewhat novel, as they are heavy steel forgings, planed into a channel section, and the total finished weight of the cage is over 10 tons. Messrs. Wright’s Forge and Engineering Company Limited claim to be the only firm in the kingdom who actually manufacture in their own works every detail required in connection with headgears, excepting the rolling of the raw material and the casting of the pulleys. They actually build headgears, kep gears, and girders, pit cages, detaching hooks, and bridle chains. All the smith work, forgings, chain making, plating, and riveting is carried out in their own shops by their own workmen. This allows them to guarantee their work with every confidence, as everything is made under the direction of their own staff, while at the same time the customer has the advantage of dealing with one firm of actual manufacturers only. The company have recently secured a contract for the Flimby and Broughton Moor Coal and Firebrick Company Limited, Maryport, Cumberland, for the following plant for their new colliery at Risehow Two headgears built from rolled steel joists; two sets of kep gear; five single-deck pit cages; five sets of cage chains; four sets, with a spare, of improved King’s detaching hooks (Player and Weddell patents). The whole of this plant will be manufactured at their works at Tipton. They have also secured a contract for a headgear for the Hamstead Colliery Company Limited, Great Barr, and are supplying one of their patent detach- ing hooks to the same company. In addition, the com- pany have a good deal of other work in hand in their structural department, including a repeat order from the Crumlin Valley Collieries Limited for pit cages and detaching hooks, and a large amount of work ror coke oven and by-product plant. WRIGHT'S F &E.CQ LT° TIPTON. WRIGHT’S E & E.C9 IJ2 TIPTON. t 1 ■J I' ?r X’iS; ■ F* Fig. 3.—Large Single-deck Cage. Fig. 4.—Large Single-deck Cage. | TELESCOPIC PIT PROPS. Although essentially a Continental development, telescopic steel props have been used in this country with a certain measure of success. We now understand that a British com- pany have recently acquired the sole manufacturing rights of the “ Nellen ” prop, one that has met with considerable favour in Germany and Belgium. The “ Nellen ” prop can be adjusted, by means of the amount of packing put into it, to any height. The pressure is taken by the packing, and a layer of elastic peat below it, encased in a lower tube. Originally Nellen made his props of tube, which bent with side pressure. To overcome this objection, the props are now constructed of steel semi-tubes with flanges, which add enormously to the strength of the prop, not only in resisting side pressure, but also vertical stresses. Both halves of the tube are perforated with a number of holes, and one is also provided with a slotted hole, this latter being covered with one of three, or more, straps, provided for the purpose of holding the half-tube in position. The construc- tion of the composite prop is briefly as follows :—A wooden plug is driven tightly in to act as a base; above this is a core of peat; above this comes the packing — gravel, coal dust, stone, or other material which may be found con- venient ; surmounting it is an inner prop of timber surrounded by an anti-splitting ring, or entirely encased by steel tube. Before erecting the prop sufficient of the packing material is placed in the inner tube to bring the prop to the desired height, and is beaten in with the inner prop. When newly set the props should be placed in a slanting position, by which means the gradual packing of the material in the inner tube by roof pressure can be taken up by driving the prop back into a vertical position, and thus increasing the pressure on the enclosed material. It has been found, in actual test, that each prop is capable of carrying loads of from 80,000 to 100,000 lb. For the removal of props a special tool is provided, com- bining a pick, hammer, and screw key. The strap covering the slotted hole having been released, a certain amount of the granulated material will flow away. By using the pick in one or two of the upper holes, and a smart tap with the hammer, sufficient material is discharged to loosen the prop, so that it may be withdrawn by ringer and chain, or other means. The flow of material is an indication that the place is safe. The absence of flow indicates a falling of the roof. Props fitted with half-round steel crowns or cross bearers are specially used in places where the roof is good, and each bearer is drilled at both ends for ease in recovery. The natural settling of the wall allows for the withdrawal of the bearer. The props are also adaptable to the supporting of rails. In this case the inner prop is provided with a special top or clip, which engages with the flange of the rail, and may be secured by set screws or keys. The “ Nellen ” props were first introduced into the Hein- rich Pit in 1908 , 200 being put in as an experiment. As a result further contracts were entered into, and the figures in the company’s books show a saving on 260,000 tons of coal of £3.500 on last year’s working, and the present monthly returns show that, at the end of the present year, the saving should be £5,000 on the year's working. In combination with the “ Nellen ” system, the methods adopted of laying rails are expected to yield a further economy of nearly £1,000 per annum. In Germany the agreement between the colliery com- panies and the manufacturers has been to pay for each prop the same price as a timber prop of equal size, and to divide the economy effected between the two companies. The system has since been adopted in Belgium and the Pas-de- Calais, and is now being tried at several collieries in this country. Fig. 5.—Heavy Forged-bar Type of Cage. “ The Coventry ” Chain Company Limited, Spon End, Coventry, inform us that up to date 130 of their employes have rejoined the Colours and enlisted since the beginning of the war. They hope to reinstate all those who re-apply at the conclusion of hostilities. The company are paying reservists’ wives 7s. per week, and Is. for each child.