It Is essential that the force vector of the weight of a coring tool act along a line that is parallel to the longitudinal axis of the core barrel. Such an alignment enables corers to obtain deeper, less disturbed core samples. The probability of bending the core barrel is furthermore greatly reduced. A fin assembly that provides the maximum righting moment for one shape of coring tool does not necessarily provide the maximum moment for a different shape. The optimum fin design is determined by testing. A fin assembly for a particular coring tool has been devised which reduces the probability of the force vector not acting parallel to the longitudinal axis. The optimum design is a vane-shroud fin assembly. The shape of the shroud is conical. Slotting the shroud by removing longitudinal strips improves the righting capability at higher angles of deviation, but is slightly inferior to the full shroud at lesser angles.

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http://archive.org/details/stabilizingfinsf1094513096

Lieutenant, United States Navy