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CHAPTER I

GENERAL CONSIDERATIONS AFFECTING METHODS OF CONSTRUCTION

volume would be required to deal fully with the manufacture of the many different parts of a locomotive and to describe the various processes in the foundries, smithy and forge, boiler-shop, machine shop, and erecting shops. Moreover the methods of construction of the various parts differ considerably in a small works, where perhaps only one or two engines are built at a time, from those in a large works, where from a dozen to fifty engines of the same class may be built to a single order. In the first case the methods and machines of an ordinary well equipped engineering shop would be used to a large extent, but in the second case there are employed special templates, “jigs,” fixtures, and above all, special machinery adapted for certain definite operations. The cost of such special machinery and appliances requires a large Rh