L-42 Boomerang Sediment Corer. — The 



Boomerang sediment rorer (by lienthos) is a 

 gravity corer tliat requires no wire or wincli for 

 launching and retrieving. It is designed to ob- 

 tain cores up to 4 feet in length from water 

 depths as great as 6,700 meters. This corer is 

 especially adaptable to those situations where 

 the wire on the ship's winches will not reach 

 the ocean floor because of excessive depths. 



The Boomerang corer assembly consists basi- 

 cally of two components: (1) The ballast com- 

 ponent; consisting of the float retaining shell, 

 ballast weight, steel core barrel with nose piece, 

 and pilot weight (fig. 1^26), and (2) the float 



PLASTIC CAP 



BALLAST WEIGHT 



PILOT WEIGHT 

 HOSE CLAMP 



■FLOAT RETAINING 

 SHELL 



FLOAT RELEASE 

 ARM 



4-FOOT PLASTIC LINER-|>; 

 Zj INCH DIAMETER 



FLOAT RELEASE 

 WIRE 



STEEL CORE BARREL 



NOSE PIECE 

 PLASTIC CAP- 



Figure L-2G. Boomerang corer ballast component. 



component; consisting of a 10-inch diameter 

 fused glass sphere, a PVC spacer, a 9-inch diam- 

 eter sphere containing the flashing assembly, a 

 nylon net bag (rigged with purse string, rubber 

 band, nylon line for stretching net bag, and a 

 float-release-arm ring), a core liner valve/re- 

 lease mechanism tube with 6-foot nylon tether 

 line, a core catcher, and a hollow rubber ball 

 (fig. L-27). The items of the float component, 

 which are recoverable, are installed in the bal- 

 last component, which is expendable. 



The complete assembly is shipped with a 48- 

 inch CAB (Cellulose Acetate Butyrate) plastic 

 liner in the core barrel and with plastic caps 

 taped over the ends of the core barrel. The 

 float-release arm and the pilot weight are con- 

 nected by a wire, and the pilot weight is held 

 snugly against the ballast weight with a hose 

 clamp. 



After being rigged to take a core, the com- 

 plete assembly is dropped overboard into the 

 ocean; it free falls and its core barrel is driven 

 into the ocean floor by gravity (fig. L^28). As 



Change 1—1970 



the Boomerang core barrel penetrates the ocean 

 floor, the float component with the sediment core 

 liner is released from the ballast component. The 

 float component then rises to the surface with 

 the core. The ballast component remains on the 

 ocean floor. 



L-43 Instructions for Assembling the 

 Boomerang Corer.— The Boomerang corer is 

 not difficult to assemble. First, the float com- 

 ponent is checked out, and it is then connected 

 up with the ballast component. The following 

 tools, equipment, and materials are required or 

 will facilitate the assembly process : 



A sphere stand (see fig. L-29) . 



A ballast component cradle (see fig. L-33). 



Screwdriver. 



A solvent (such as trichloroethylene) . 



Electrical vinyl tape. 



Fiber vinyl tape. 



Tubular tool. 



Silicone gasket grease. 



Float recovery hook. 



Net, long handle. 



Step 1. Check the battery and the electronic 

 circuit of the flashing component by removing 

 the magnetic switch from the side of the 9-inch 



10" FUSED GLASS SPHERE 

 NYLON NET BAG 

 RUBBER BAND 



MAGNET SWITCH 



VALVE /RELEASE MECHANISM 

 TUBE AND TETHER LINE 



Figure L-27. Boomerang corer float component. 



Lr-23 



