The Mechanical Handling and Storing of Material

ROPE WA YS 275 inclines. The problem has, however, been solved in 1896 by the introduction of a device by Bleichert, illustrated in Fig. 400. This grip goes by the name of the “ Automat,” and consists of a sliding block a, which moves in a vertical direction in the frame b. A pin c is attached to this block, and the carrying frame d is suspended from this pin. One of the jaws e is rigidly connected with the framework of the trolley, whilst the other one f is connected to the sliding block a (and indirectly to the pin d) by a connecting link g. The throwing in and out of this coupling is effected by slightly raising or lowering the load on the rope. The roller h is for this purpose, as this rests on small auxiliary rails at the loading or unloading stations. It is claimed for this coupling that the grip is sufficient to fulfil all the requirements of the modern ropeway without the use of knotted ropes. Advantages and Disadvantages of the Two Systems.—As regards the initial outlay, the single ropeway is simpler; having only one rope and requiring no expensive couplings, it is therefore less costly, although the supports should be closer together, as it is more difficult to keep a running rope taut than a stationary one. The working expenses, that is the labour, would be the same in both systems. The double ropeway is more applicable to difficult routes deviating from the straight line. It can negotiate steeper gradients and, finally, it is more suitable for large individual loads than the single rope system; firstly, because corners are more easily turned with a double ropeway; secondly, because the A-shaped saddles do not exercise such a positive grip as some of the gripping devices of the double ropeway; and thirdly, because the rail rope is stronger, tighter, and thus more rigid, to cope with heavy individual loads. A rope of the single system can be minutely examined and oiled whilst passing through one of the terminal stations, but with a double ropeway a man has to travel in one of the skips for this purpose. Cost of Transport.—This must necessarily vary with the conditions, but generally speaking the working expenses of a ropeway compare favourably with those of a railway. On some well-planned and well-laid ropeways the wear and tear of the ropes, which is actually the largest item of expense, is said to be between id. and |d. per ton per mile. Broadly speaking, the cost of handling must vary with the natural obstacles on the route and the quantities to be carried. An example which may be mentioned to show the wear and tear of rail ropes is that of a ropeway erected by Messrs Bullivant & Co., Ltd., in Spain, which was employed to convey loads of from 300 to 350 tons per day a distance of 1 mile between Badovalle and Ortuella, so that it is estimated that one rope carried over 160,000 tons. As the rope- way was at work incessantly from July 1893 to July 1895, the cost of rope renewal meant an expenditure of ^d. per ton per mile. The rope when new had a breaking strain of 29^ tons, and the test showed that the disused rope had still a breaking strain of 27| tons. As will be seen later, Ropeways, Ltd., estimate the total cost, including, in addition to rope wear, all renewals, grease, stores, etc., at |d. per ton per mile. I he figures given do not, however, include cost of labour or power, which two items vary with every installation. Cost of Maintenance.—One of the most important questions in a ropeway installation is the cost of maintenance, and as this is almost exclusively confined to the renewal of the rope or ropes, it may be well to investigate this subject more fully. It is obvious that the function of and the demand upon a rail rope is different to that of a haulage rope. The former would naturally have to be made of the stoutest possible wires