Upon arrival at the test site, the ship was anchored in a two-point 

 (bow-stern) moor with the aid of a LORAC B positioning system. The ship 

 was directed into the surface current to reduce lateral drift. The 

 LORAC B records show that the ship did not drift more than 40 feet at 

 each test site. 



DOTIPOS was prepared for the first test series by attaching either 

 the vane or cone. The hoist lines for DOTIPOS were then connected to 

 the ship's deck crane, and DOTIPOS was lifted over the side of the ship. 

 At a water depth of 15-20 feet, the DOTIPOS support-telemetry cable was 

 made taut, and the load on the deck crane was relieved. SCUBA divers 

 were used to detach the DOTIPOS hoist and handling lines from the deck 

 crane. DOTIPOS was then lowered to the bottom, and extra support-telemetry 

 cable was provided to prevent test disturbance from ship drift. 



Two or three cone penetrometer tests were normally performed 

 consecutively. Figure 8 shows the cone penetrometer on the ship's deck 

 in its test ready position. From the surface control cabin, the vertical 

 displacement of the cone penetrometer was controlled, and the displace- 

 ment and axial cone load were monitored on an oscillograph recorder. 

 Proper test performance requires use of the TV camera. The television 

 camera is an invaluable visual aid in that it allows the operator to 

 accurately position the cone on the sediment surface prior to initiating 

 each cone penetrometer test. Without the camera, penetration readings 

 could be off by several inches due to settlement of the reference platform 

 (DOTIPOS). The surface sediment is very soft and cone penetration could 

 initially go undetected. After each test, DOTIPOS was lifted approximately 

 20 feet above the seafloor and repositioned over an undisturbed patch 

 of soil. The remainder of the cone penetrometer tests were performed 

 according to this procedure, and DOTIPOS was returned to the deck of the 

 support ship. 



The cone penetrometer tool was replaced with a vane shear tool in 

 preparation for the vane shear tests. DOTIPOS was returned to the seafloor 

 and positioned for a set of vane shear tests. (Each set of vane shear 

 tests consists of individual tests at incremental depths in the soil 

 profile.) From the surface control cabin, the vane tool, shown on the 

 ship's deck in Figure 9, was pressed into the soil in increments of 

 1 foot. As with the cone test, the TV camera is used to accurately 

 position the vane on the sediment surface. At each increment, the vane 

 was rotated in the undisturbed soil at 1 rph (6 deg/min) until a peak 

 shearing resistance was recorded on the oscillograph; the peak shear 

 strength usually occurred within 3 to 5 minutes. The remolded shear 

 strength was then obtained by rotating the vane one revolution at a high 

 angular velocity (10 rpm) , stopping vane movement for one minute, and 

 continuing the test at the slow angular velocity (1 rph) . The final 

 depth of each test was limited by either the maximum displacement of the 

 vane shear device (10 feet) or a soil which prevented maximum penetration. 



