Excerpt from The Block System of Signaling on American Railroads: The Methods and Appliances Used in Manual and Automatic Block Signaling
The block system is now in use on over 25,000 miles of railroad in America, and it seems likely that this mileage will be steadily increased. Ten years ago, when "American Practice in Block Signaling" was issued, only about one-tenth this number of miles of railroad was worked in this manner; and but few railroad companies appeared to deem block signals necessary. Now, over fifty roads have adopted the system for at least a short length of line, and 27 of them have it in use on over 100 miles each. This fact - that prominent companies all over the country now fully appreciate the value of the space-interval principle, and are putting it in use on their busiest lines - is the most important one to be noted in this revised edition of "American Practice." But the numerous modifications and improvements in electrical and other machinery used in block signaling, which have been made since 1890 are of at least equal interest; and the bulk of the book is, of course, taken up with these.
The matter has been entirely rewritten. Nearly or quite every mechanical or electrical device described in the former work has been improved or superseded, and the illustrations now given are all new. Illuminated semaphores have made no progress and are omitted.
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. Это и многое другое вы найдете в книге The Block System of Signaling on American Railroads (Braman Blanchard Adams)