said that he wished first to congratulate Mr Alexander on his Paper and on his subject. It seemed to him that the particular subject was very important for the railways and introduced many important items in modernization.62. In the old type of yard with clasp brakes, if the wagon did not conform or the weather conditions changed one had the problem of the wagon stopping short or buffing-up a t too high a speed. The Dowty units solved the problem of varying rollability.
63.The Dowty installation was the latest development in marshalling yards but, of course, all kinds of developments had been going on through the years both in Britain and abroad. He had read most of Mr Alexander's papers and accounts of yards in the United States, Canada, and the United Kingdom and Europe, and there was one item which seemed to him to be most important and yet never seemed to be mentioned. If one followed the processes of a marshalling yard step by step and took these in conjunction with the types of wagon to consider what was the best type of wagon for any process, one reached the rather strange conclusion that the most satisfactory wagon for the purpose was the old-fashioned British standard wagon, i.e. the wagon fitted with loose-link coupling and a hand brake which could be operated by the shunter from either side.
64.Modern wagons had screw couplings and piped brakes, either vacuum or pressure, but in either case the procedure was the same. To undo the brake the man had to step between the wagon and the rails, and he had to do the same for screw coupling. The net effect was that the processing of a series of modern wagons through a yard of this type actually took longer than a series of the older wagons. Also, when the shunter disconnected the pipe at a cut, owing to the requirement that when a train divided by accident the brakes must go on, the mere act of loosening the pipe would put the brakes on, and the shunter still had to exhaust the reservoir before the trucks became mobile. Because of this need, in the case of countries with long trains to which power brakes were fitted, when a train arrived at a marshalling yard the first act of the shunters was to bleed the pipe throughout the train. In some cases this might take about an hour. One therefore had the peculiar anomaly that the most sophisticated yard seemed to be built in order to process the most old-fashioned type of wagon, and it appeared that if one had a modern wagon in that yard it would take longer to process and cause more trouble.65. It would seem that the answer to the problem was an automatic coupling which would operate both the couplings and the brakes simultaneously. The requirements of such a coupling should be as follows :(U) if there was an accidental parting of two halves of a train the brakes must come on immediately ; (b) the shunter must be able to pull a lever which would automatically release the coupling and the pipe, and also operate the valve so that the brakes would not be thrown on, after which the cuts could be humped;
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