COALING WARSHIPS FROM COLLIERS IN HARBOR. 



By Spencer Miller, Esq., Member. 



[Read at the eighteenth general meeting of the Society of Naval Architects and Marine Engineers, held in 



New York, November 17 and 18, 1910.] 



Commander A. P. Niblack, U. S. N., said before this Society in 1893 :^ 



"Coal supply and rapid coaling are very important factors in efficiency, 

 not only in an emergency but in time of peace, for the time spent in coaling 

 ship is time wasted."* 



One of the United States colliers (purchased during the Spanish- 

 American war) discharged with its own gear from its four hatches 1,200 

 tons of coal in ten hours, 120 tons per hour or 30 tons per hour per hatch. 

 About 100 men were required to fill the coal bags in the hold. For a single 

 hour 50 tons of coal per hatch may be discharged by such means. 



In contrast to this the U. S. Navy collier Hector discharged 190 tons 

 of coal from one hatch in one hour, employing a self -filling bucket operated 

 by two men. This means a great saving in "manual labor as well as a 

 saving of time. The importance of reducing the labor of coaling in time of 

 war is apparent to everybody. 



Our (United States) Navy Department began a few years ago to build 

 colliers from their own designs or prescribed characteristics. The first two 

 were the fleet colliers Vestal and Prometheus, both i6-knot ships, carrying 

 6,400 tons of coal each. Next were the Mars, Vulcan and Hector, sister 

 ships, with 12 knots speed and 7,200 tons carrying capacity. The colliers 

 Cyclops and Neptune, now under construction, will have 14 knots speed 

 and carry 12,500 tons of coal each. All of these colliers, excepting the 

 Cyclops, carry a novel form of coal-discharging gear known as the Marine 

 Transfer. The Cyclops will discharge its coal by self-filling buckets but 

 with a different operating system not described in this paper. 



TH^ MARINE TRANSFER ON THE COIylvlERS VESTAI, AND PROMETHEUS. 



The collier Vestal (Figs, i, 2 and 3, Plates 33 and 34) was built at the 

 New York Navy Yard. The Prometheus, a sister ship, was built at the 

 Mare Island Navy Yard. Each ship has eight hatches. Between each pair 

 of hatches is a tall, vertical spar carrying four steel booms for the Marine 

 Transfer and two for other service. Grouped about the base of each mast 



* "Coal Bunkers and Coaling Ships." 



