APPENDIX No. I EXTRACT FROM REPORT OF THE CHIEF OF BUREAU OF STEAM ENGINEERING, RELATING TO COMPARATIVE TESTS OF COAL AND OIL MADE UNDER A WATER-TUBE BOILER OF THE HOHENSTEIN DESIGN, ALSO OFFICIAL REPORT OF THE STEAMSHIP MARIPOSA BURNING LIQUID FUEL The Problem of the Water-Tube Boiler-The Hohenstein Boiler Trials (Coal Tests). THE HE experience of the United States Navy with the boilers of the torpedo boats and torpedo-boat destroyers ought to afford some startling evidence as to the manner in which incompetent or untrained men can impair or destroy the efficiency of these steam generators. The agitation of Great Britain over the navy-boiler question ought also to convince naval administrators that the boiler problem is the naval problem of the hour. In view of the British experience with the Belleville boiler, it is not surprising that the general public of that Empire regard the Boiler Commission, now in session, as the most important board appointed by the Admiralty during the past ten years. The membership of this board comprises distinguished experts within and without the naval service. This board has been in session nearly two years investigating the question as to which type of marine boiler is most suitable for use in the navy as the one of approved design. The Admiralty regard the solution of this problem as of vital importance to the efficiency of the British fleet, for it has been discovered, after installing over a million and a quarter of horse-power of boilers of particular design, that a doubt has arisen as to whether or not this particular form of boiler should have been settled upon as the approved type for the naval service. A series of evaporative and endurance tests have been made, and the more carefully the question is investigated the more important does it appear in relation to the operation of a modern navy. The work of the British Boiler Commission will have a very important influence upon naval construction, since it will cause thoughtful experts to give more attention to the design, construction, installation, and operation of the boiler. One must have experience in the operation of a modern marine boiler to appreciate the intelligence, skill, and care that must be devoted to keeping it in a state of efficiency. The boilers are the lungs of a vessel, although this fact is not generally understood. It was not many years ago when a naval officer of high rank spoke of the boilers as the steam tanks in the bottom of the ship," it being probably his impression that these tanks could be tapped like a gasometer, and it was the fault of the fireman if the boiler output was not sufficient at all times. The boiler problem has been unsolved. Without taking into consideration the question of personnel, the value of the warships of the different naval Powers can be measured by the efficiency and endurance of the steam generator installed in the vessel. This fact may not be appreciated in its fullness at the present time, but the experience of the coming five years with the ships nearing completion will conclusively show that in future naval conflicts the question of victory may be quite as much dependent upon the battle of the boilers as the contest between the guns. With a deep appreciation of the necessity of soon settling upon an approved type of marine boiler for the battleships and armoured cruisers of the United States Navy, the Bureau has invited competition among desimers. It believes, however, that, if possibla a biler of American de n should be adopted, and that this marine boiler should be a development of one in general use on shore. By seeking a design that is familiar to th sands of firemen on ore, an important military advantage would be secured, since in tine of emergency there could thus be recruited for the naval service water tenders and firemen who had operated almost similar steam generators, and would therefore require bat little training to familiarize themselves with the duty on board ship. While the navy can and ought to do some efficient work in training firemen, it would be very advantageons to the service if the enlisted force in the stokeholds could have considerable preliminary training with boders of nearly like design to the one in most extensive use as the approved type for the navy. There is now being built, for the battleships in course of construction, water-tube bollers of three distinct types. Practically four-sevenths of this boiler power will be of the Babook & Wilcox design. two-sevenths of the Niclausse, and one-seventh of the Thomycroft. These types include the best of representative groups of water-tube boilers. and a suthient installation of each kind will be secured to test the efficiency and endurance of the several designs. About two years ago the Bureau was informed that another American boiler firm, with considerable financial backing, desired to enter the field of marine-boiler construction. In keeping with the Bureau's policy of inviting competition, encouragement was therefore given the Oil City Boiler Works to design and build a marine boiler and turn it over to the Bureau for test as to its evaporative efficiency and endurance, and they placed at the disposal of the Bureau a boiler of the Hohenstein design, installed in an air-tight steel house, approximating to one of the fire rooms of the cruiser Denver. All the limitations and difficulties that were met with in the installation of the boilers of the cruiser Denver were therefore designedly encountered in the installation of the experimental plant. Information has been secured in regard to the best means of baffling the gases, thus increasing the evaporative efficiency as well as permitting the boiler to be forced for emergency purposes. Particular care has also been given by the Board to the investigation of the circulation of the water, for probably the key to the boiler problem is the question of circulation. While only seventeen official tests were made with coal as fuel, there were a great many unofficial experiments. Between the several official tests the experts of the Oil City Boiler Works conferred with the Bureau, and therefore each test represents the result of study and experiment. An examination of the data will conclusively show that in many respects the completeness and character of the tests have never been surpassed. The first six tests were run by a picked crew of firemen who had experience in torpedoboat work. It was believed that these men by training and experience were particularly well fitted to operate the boiler when under severe forced-draught conditions. An experience of a few weeks with this force showed that new methods in firing had to be employed in efficiently operating water-tube boilers, and that the best means of securing efficient work was to have skill and intelligence from those in charge of the fire room and implicit obedience upon the part of the subordinates. The remaining eleven tests were thus made by firemen living in the city, not one of whom had ever before worked a boiler under forceddraught conditions. The second set of firemen implicitly obeyed orders, and it was therefore possible for the Board to have its instructions carried out. A uniform pressure of steam was maintained, as well as a regularity in firing that was productive of good results. The data secured can be regarded as reliable, for checks and counter-checks were used, so that the Bureau could be placed in possession of information that could be relied upon as to completeness and accuracy. As this same boiler is being used to carry on the extended series of tests to determine the value of liquid fuel for naval purposes, it is proposed to duplicate every one of the coal tests with oil as a combustible. The comparative information thus obtained ought to afford valuable data as to the relative value of the two combustibles. In view of the present condition of this experimental boiler after eighteen months of use with both coal and oil as a combustible, considering the results secured, and by reason of the following report submitted by the Board which conducted the series of tests, the Bureau has no hesitation in regarding the boiler as the equal in efficiency and endurance of any used in a foreign battleship. Report of Board on Hohenstein Boiler Trials. NAVY DEPARTMENT, BUREAU OF STEAM ENGINEERING, July 1, 1902. SIR,-The Board appointed to conduct an extended series of tests to determine the Fig. 1.-ARRANGEMENT OF HOHENSTEIN EXPERIMENTAL BOILER FOR COAL BURNING TESTS efficiency and adaptability of the Hohenstein marine boiler for naval purposes submits the following report The boiler was built by the Oil City Boiler Works, of Oil City, Pa., in conformity with the Bureau specifications for the cruiser Denver and class. The limitations as to weight, height, and floor space in regard to the Denver's steam generators were therefore taken into account in the construction of this boiler. A noteworthy feature of the boiler is the |