Author: B. Baker

Publisher: Forgotten Books

Published: 2018-02-09

Total Pages: 134

ISBN-13: 9780656186884

Excerpt from Long-Span Railway Bridges: Comprising Investigations of the Comparative, Theoretical and Practical Advantages of the Various Adopted or Proposed Type Systems of Construction According to Dr. Johnson, a bridge is a structure to carry a road across a watercourse, and although this interpretation of the word is not sufliciently comprehensive to include all cases in the present progressed stage of the art of building, yet, if we limit its application to long spans alone, we may even render it still more explicit, and with very little liability to error define a long-span bridge to be a structure for carrying a railway across a watercourse. The reasons why this is the case are sufficiently obvi ous; in the first place, the condition necessitating the adoption of a long span is generally either that a certain width of opening must be provided clear of all obstructions, or that the expense of carrying up a number of lofty piers is, owing to some difficulty in obtaining secure foundations, so great as to render it more economical to reduce the number of individual supports, and so concentrate the resulting greater load on fewer points. Neither of these conditions is likely to occur, except when a watercourse is the oh staels to be surmounted, when, probably, a navigable. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.