284 HYDROGEAPHIC MANUAL Page 178 



284. SoNo-RADio Buoy 



The sono-radio buoy, which is used to replace shore and ship R.A.R. stations in 

 most of the offshore surveys, is a comparatively recent innovation. 



The possibility of using a sono-radio buoy to replace a ship R. A. R. station was 

 first proposed in 1931. Actual development was started in 1932-3, postponed, and 

 resumed in July 1935. A sono-radio buoy was first successfully tested at sea on June 

 13, 1936, and they were in actual field use by the ships Lydonia and Hydrographer in 

 July 1936. This was after the design of survey buoys had been more or less standard- 

 ized, so it was natural that the first sono-radio buoy should resemble the survey buoy 

 that had proved to be so satisfactory. 



There are two types of sono-radio buoy structures: One is an adaptation of the 

 standard one-barrel survey buoy, modified to enclose the electric equipment and to 

 serve for the sono-radio buoy structure. It is used principally on the Atlantic and 

 Gulf Coasts and is known as the East Coast sono-radio buoy. The other, known as 

 the Vincent sono-radio buoy, is of all-metal construction and is adapted for use on the 

 Pacific Coast and in Alaska. ' These buoy structures cannot be considered standard, 

 as further developments and unprovements are to be expected. The electric equipment 

 for these buoys is described in section 65. 



2841. East Coast Sono-radio Buoy 



The sono-radio buoy that has been developed for use on the East Coast (fig. 50) 

 is similar to the one-barrel buoy described in 2824, but is of heavier construction to 

 adapt it for use in any locality and to support a heavier counterweight and the sus- 

 pended hydrophone. The superstructure is made slightly longer to accommodate the 

 required length of anteima. 



In localities free from strong winds and currents, a sono-radio buoy similar to the one-barrel 

 survey buoy but somewhat lighter in construction, has been satisfactorily used. The superstructure 

 is made of 1- by 4-inch lumber instead of 2- by 4-inch as is used in the one-barrel buoy. A special 

 150-pound cast-iron weight, cast to fit between the lower ends of the vertical members, is used as a 

 counterweight. 



The following specifications and list of materials are for the standard East Coast sono-radio buoy. 

 The electric equipment is described in 652. 



(A) SPECIFICATIONS FOR EAST COAST SONO-RADIO BUOY 



The lower parts of the vertical members are 4 by 4 inches in size, each formed of two pieces of 

 2- by 4-inch by 18-foot lumber, spiked together, to which the counterweight is attached. The one 

 car coupler, with added weight, composing the counterweight is held firmly between the two vertical 

 members by two through bolts. Wooden wedges are driven between the upper end of the car coupler 

 and the frame at the upper bolt, to prevent any movement in the frame which might result in a sound 

 that could be picked up by the sensitive hydrophone. 



Two barrels, a large and a small one, are generally used for greater stability, but it may be con- 

 structed with the larger barrel alone, in which case the size of the counterweight must be litnited to 

 one standard car coupler of 180 or 200 pounds weight. The large barrel, made of 16-gage galvanized 

 iron, is 40}^ inches high, 22 inches in diameter, has a capacity of about 65 gallons, and contains all the 

 radio equipment and batteries. The barrel usually used for this purpose is Wilson and Bennett Com- 

 pany No. 6546G, or equal. 



The smaller barrel is made of 19-gage galvanized iron, is approximately 38 inches high and 18 

 inches in diameter; it contains no equipment and it is used only for additional buoyancy. Wilson 

 and Bennett Company barrel No. 3539(7, or equal, is satisfactory for this purpose. 



The large barrel has a detachable cover, 15 inches in diameter, held in place by twelve ^le-inch 

 bolts and made watertight by a tubular rubber gasket that fits under the cover. In the center of 

 the detachable cover is a 2H-inch threaded opening, fitted with a screw plug, through which the sen- 



