Report of Board on Comparative Trials of the Scout Cruisers, Birmingham-Salem-Chester

Excerpt from Report of Board on Comparative Trials of the Scout Cruisers, Birmingham-Salem-Chester: December 22, 1909 Sir: The Board appointed by the Navy Department, under orders dated October 21, 1908, to carry out comparative tests of the main and auxiliary machinery of the scout cruisers U. S. S. Birmingham, Salem, and Chester, having finished the work assigned to it, respectfully submits, as directed, the following report, embracing an analysis of the results obtained, together with a copy of the data recorded during the various tests made. Object and Description of Tests. The object of the tests was to ascertain and compare the steam economy of the three types of propelling machinery fitted in the vessels named, the hulls being practically of the same model, at various speeds while underway and under as nearly as possible identical conditions. To accomplish this, special water-measuring apparatus was built and installed in each ship for the tests, and so arranged that the weight of steam used by the propelling, machinery, as well as the auxiliaries, could be, after condensation, separately and accurately ascertained. In order to make the comparison complete, six distinct series of tests were carried out, as follows: I. Tests of auxiliary machinery (vessel in port). II. Boiler evaporative tests (vessel in port). III. Standardization runs. Each vessel was standardized over the Rockland measured mile course just prior to undertaking the (IV) steam-consumption tests. As will appear later, this involved standardizing the Salem on two different occasions, as two series of steam-consumption tests were carried out. In these trials, moreover, and as well as all other (V and VI) sea runs, the aim was to load each vessel so that the displacement for each trial should be as nearly as could be calculated in the beginning, an average of 4,000 tons. All ships were dry-docked prior to standardization and coal-consumption trials, and the bottoms cleaned and painted. IV. Steam-consumption tests of main and auxiliary machinery (vessel under way). V. Coal-consumption tests of about 1,000,750, and 2,000 knots at speeds, respectively, of 10, 15, and 20 knots per hour. VI. A full power run of twenty-four hours' duration. The Birmingham was unable to complete this trial on account of a defect which developed in the machinery. This vessel, after finishing twelve hours of the test, slowed down and returned to port. 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.