Core Sampling In the Hudson Bay

1. Abstract The purpose of this paper is to report on coring operations carried out by International Hydrodynamics in the Hudson Bay during the summer of 1971. During these operations core samples were taken on a number of locations using a surface delivered and operated coring device and a submersible delivered and operated coring device. The surface operated coring device was worked from the submersible support vessel Hudson Handler and the submersible delivered coring device was worked from the submersible Pisces III. It is concluded that surface and subsurface core sampling operations can be successfully and economically carried out in remote locations for extended periods of time. In mid 1970 International Hydrodynamics personnel were in the Hudson Bay for the first time on board the new submersible support vessel MV Hudson Handler (see Annex A), which was on its maiden voyage. The vessel had been recently constructed in Selkirk, Manitoba and transported by rail to Churchill where it was assembled. They were there along with the submersible Pisces III to support an undersea program for Aquitaine Oil, primarily to work on a well head. As a result of the success of this program the possibility of carrying out a bottom sampling program in the same area was discussed and was deemed to be feasible. It was therefore decided to undertake such a program the following year. This would be an ambitious endeavour because most of the hardware to undertake the program did not exist. However, having conceived the program both parties were eager to make it go, although at times it was easier said than done. The program called for a 3000 mile track and a minimum of 55 days in the "Bay". In addition to the sampling program, representatives from the Canadian Inland waters Branch of the Department of Energy, Mines and Resources (DEMR) would also be on board to carry out a bottom profiling and sampling program of their own. For the Aquitaine program it was decided that both a submersible mounted and a surface supported coring device would be used for bottom sampling. The submersible mounted hard rock coring device, Figure 2, was designed and built specifically to support the program in the "Bay". The corer is capable of taking rock cores 5/8 inch in diameter, up to 10 inches long using a diamond tipped drill. As presently configured the drill is powered hydraulically from a 1500 psi, 2 gpm source which drives the bit at 500 rpm. The bit is cooled and lubricated by water pumped through the barrel of the drill by a small rubber impeller water pump which is driven off the drill motor. The core barrel is advanced by an hydraulic cylinder driven from a hand pump within the submersible. This allows the pressure and advance rate to be modified to suit rock conditions. Advance rates of up to 2 in./min. have been measured in granite.