The tandem pulley comprises a pair of sheaves mounted in line between first and second flanges. A gate is fitted rotating with respect to the first flange between closed and open positions. The gate comes into contact with the second flange in the closed position to close a housing. The clamp is movable in rotation on the gate between a locking position locking the gate in the closed position and an unlocking position. The clamp has a prong pressing on the first flange and the gate in the locking position. The clamp has an actuating area separated from the first flange by the gate. Rotation of the actuating area from the locking position to the unlocking position corresponds to a movement of the actuating area away from the second flange. Rotation of the actuating area results in pivoting of the prong.

The tandem pulley comprises a pair of sheaves mounted in line between first and second flanges. A gate is fitted rotating with respect to the first flange between closed and open positions. The gate comes into contact with the second flange in the closed position to close a housing. The clamp is movable in rotation on the gate between a locking position locking the gate in the closed position and an unlocking position. The clamp has a prong pressing on the first flange and the gate in the locking position. The clamp has an actuating area separated from the first flange by the gate. Rotation of the actuating area from the locking position to the unlocking position corresponds to a movement of the actuating area away from the second flange. Rotation of the actuating area results in pivoting of the prong.

A deepwater hoisting system includes a synthetic fibre rope winch assembly including a motor driven first winch and a length of synthetic fibre rope driven by said first winch. The synthetic fibre rope has an end remote from the first winch. The system further includes a steel wire winch assembly including a motor driven second winch and a length of steel wire driven by said second winch. The steel wire has an end remote from the second winch. At least the second winch is an active heave compensation motor driven winch. The system further includes a lifting block having a lifting block sheave, through which the synthetic fibre rope is run. The end of the synthetic fibre rope is connected to the end of the steel wire, so that the lifting block is suspended in a double-fall arrangement.

A deepwater hoisting system includes a synthetic fibre rope winch assembly including a motor driven first winch and a length of synthetic fibre rope driven by said first winch. The synthetic fibre rope has an end remote from the first winch. The system further includes a steel wire winch assembly including a motor driven second winch and a length of steel wire driven by said second winch. The steel wire has an end remote from the second winch. At least the second winch is an active heave compensation motor driven winch. The system further includes a lifting block having a lifting block sheave, through which the synthetic fibre rope is run. The end of the synthetic fibre rope is connected to the end of the steel wire, so that the lifting block is suspended in a double-fall arrangement.

A hoist assembly includes: a rope; a first mount having a base and a pulley attached to the base; a second mount having a base and a pulley attached to the base; a first lift pulley movably associated with the first mount with the rope; a second lift pulley moveably associated with the second mount with the rope; a pair of support straps; a bracket located on each of the first lift pulley and second lift pulley for receiving one of the pair of support straps and one or more apertures formed through a side wall of the bracket; and a lateral strap secured at a first end through the one or more apertures of the bracket of the first lift pulley and at a second end through the one or more apertures of the bracket of the second lift pulley.

A pipe replacement system and cable guide frame are shown. Configurations are shown that include plurality of guide pulleys attached to the cable guide frame to define a curved path between a pipe to be replaced and a cable pulling system. Configurations are shown where a pipe breaking tool is pulled over the plurality of guide pulleys for ease of removal after a replacement operation. Configurations are also shown that include a stationary splitter adjacent to the cable pulling system to prevent jamming of the cable pulling system.

A pipe replacement system and cable guide frame are shown. Configurations are shown that include plurality of guide pulleys attached to the cable guide frame to define a curved path between a pipe to be replaced and a cable pulling system. Configurations are shown where a pipe breaking tool is pulled over the plurality of guide pulleys for ease of removal after a replacement operation. Configurations are also shown that include a stationary splitter adjacent to the cable pulling system to prevent jamming of the cable pulling system.

Improvements to a pulley is disclosed. The rope is threaded through the self-locking pulley in the desired direction. At some places, the threading passes the rope or strap in opposing directions to cause a binding and prevent free movement of the rope or strap in one direction. There are no one-way clutches or self-locking teeth to lock movement in a particular direction. A first part it secured to a spinning mount or ceiling so a user can walk around a suspended self-locking pulley and pull the rope or strap from any direction. The second part can pivot and move up-and-down on the first piece. A threaded member alters a frictional lock between the at least two interconnecting pieces. The interaction of the at least two pieces allows for lifting, locking and lowering of a load on the rope or strap.

Improvements to a pulley is disclosed. The rope is threaded through the self-locking pulley in the desired direction. At some places, the threading passes the rope or strap in opposing directions to cause a binding and prevent free movement of the rope or strap in one direction. There are no one-way clutches or self-locking teeth to lock movement in a particular direction. A first part it secured to a spinning mount or ceiling so a user can walk around a suspended self-locking pulley and pull the rope or strap from any direction. The second part can pivot and move up-and-down on the first piece. A threaded member alters a frictional lock between the at least two interconnecting pieces. The interaction of the at least two pieces allows for lifting, locking and lowering of a load on the rope or strap.

Described herein is a hoist fleet system including a head block and a guide fleet assembly. The head block includes a plurality sheaves having more than one diameter. The guide fleet assembly can be arranged proximate the head block such that an array of lift lines can be routed through the plurality of sheaves of the head block into the guide fleet assembly. The guide fleet assembly further includes a plurality of guide sheaves and a plurality of plates. The plurality of plates is configured to house the plurality of guide sheaves. The plurality of guide sheaves is positioned substantially orthogonal to the head block. The plurality of plates is further arranged such that the plurality of guide sheaves is arranged on more than one plane. The plurality of guide sheaves is configured to reduce the spacing of the lift lines.