Figure 1. The gasoline engine power source, along with 26 

 feet of flexible extension shaft, the vibrator 

 head, and the quick fasten-release clamp. 



penetration of the core tube; during the short period of time it takes to shut 



down the engine and reattach the vibrator head some of the sediments will have 



already begun to densify. (b) The higher placement of the vibration head on 

 the core tube has been shown to improve vibration and core penetration. 



The quick fasten-release clamp, which is designed to rigidly and quickly 

 attach the vibrator head to the coring tube, is made from a section of schedule 

 40 steel pipe (see Table for specifications) about 8 inches (20 centimeters) 

 long (Fig. 2). The pipe was cut in half longitudinally, and each piece hinged 

 on one side with two bolt plates and two slot plates welded near the top and 

 bottom of the other side. The clamp which is welded to the vibrator head is 

 then fastened around the coring pipe by two hex head bolts, nuts, and lock- 

 washers. The quick fasten-release clamp may be moved up and down the coring 

 pipe like a "sleeve" by simply loosening the nuts and bolts, eliminating 

 having to completely remove the unit from the core tube. This design is an 

 im.provement over standard U bolts that often bend or break and take consider- 

 ably more time for rem.oval and reattachment. 



2. Tripod . 



Important criteria in coring are the sturdiness and the safety of the 

 tripod used to extract the cores. The tripod shown in Figure 3 meets these 

 criteria. It has four separate components: three 14-foot-long legs of schedule 

 40 aluminum pipe and an aluminum tripod head (see Table for specifications) . 

 Step supports welded to one leg provide easy attachment of the come-alongs to 

 the tripod head. At the base of each leg is a 12-inch-diameter (30.5 centi- 

 meters) pivoting footpad which prevents the tripod legs from sinking into the 

 ground during extraction of the filled core tube. 



