An interlock system includes first and second connectors for connecting a boom section to a boom. A first cover is provided for covering an actuator for actuating a first connector when a second connector is withdrawn from a position for connecting the boom section to the boom. A first block may also be provided for blocking a first receiver in an operative condition to prevent the first connector from entering the first receiver. The connector may be adapted for movement along an insertion axis corresponding to a first receiver on the boom section and a second receiver on the boom, and an actuator may be provided for advancing or retracting the connector, the actuator extending generally parallel to, but offset from, the connection axis. Related methods are also disclosed, as is an axially offset actuator for actuating one or more of the connectors for connecting the boom section to the boom.

An interlock system includes first and second connectors for connecting a boom section to a boom. A first cover is provided for covering an actuator for actuating a first connector when a second connector is withdrawn from a position for connecting the boom section to the boom. A first block may also be provided for blocking a first receiver in an operative condition to prevent the first connector from entering the first receiver. The connector may be adapted for movement along an insertion axis corresponding to a first receiver on the boom section and a second receiver on the boom, and an actuator may be provided for advancing or retracting the connector, the actuator extending generally parallel to, but offset from, the connection axis. Related methods are also disclosed, as is an axially offset actuator for actuating one or more of the connectors for connecting the boom section to the boom.

A holding device for use with a telescopically extensible crane boom (57) in order to keep a load handling tool (4) in a given parking position in relation to the crane boom. The holding device (1) comprises: an attachment (10) to be fixed to an end of a telescopic crane boom section of the crane boom; a tool holder (15), which is detachably mountable to the attachment (10) and configured for engagement with the tool in order to support it against the crane boom and keep it in the parking position, the tool holder being provided with a sliding member (28), through which the tool holder is configured to slidably rest against an external surface on the crane boom; and a locking mechanism (16) for locking the tool holder and the attachment to each other when the tool holder is mounted to the attachment.

A marine knuckle boom crane includes a crane housing which is rotational relative to a pedestal about a vertical rotation axis and a knuckle boom assembly attached to the crane housing. The knuckle boom assembly includes a main boom, the inner end of which is connected pivotably about a first horizontal pivot axis to the crane housing; and a jib, the inner end of which is connected pivotably about a second horizontal pivot axis to the outer end of the main boom, wherein the jib is pivotable at least between an extended position in which the tip extends mainly forward from the main boom, and a folded position in which the jib is folded back, essentially parallel along the main boom. In order to position the jib with respect to the main boom, a tensioning member is provided extending between the crane housing and a curved extension guide connected to the jib.

A marine knuckle boom crane includes a crane housing which is rotational relative to a pedestal about a vertical rotation axis and a knuckle boom assembly attached to the crane housing. The knuckle boom assembly includes a main boom, the inner end of which is connected pivotably about a first horizontal pivot axis to the crane housing; and a jib, the inner end of which is connected pivotably about a second horizontal pivot axis to the outer end of the main boom, wherein the jib is pivotable at least between an extended position in which the tip extends mainly forward from the main boom, and a folded position in which the jib is folded back, essentially parallel along the main boom. In order to position the jib with respect to the main boom, a tensioning member is provided extending between the crane housing and a curved extension guide connected to the jib.

A marine knuckle boom crane includes a crane housing which is rotational relative to a pedestal about a vertical rotation axis and a knuckle boom assembly attached to the crane housing. The knuckle boom assembly includes a main boom, the inner end of which is connected pivotably about a first horizontal pivot axis to the crane housing; and a jib, the inner end of which is connected pivotably about a second horizontal pivot axis to the outer end of the main boom, wherein the jib is pivotable at least between an extended position in which the tip extends mainly forward from the main boom, and a folded position in which the jib is folded back, essentially parallel along the main boom. In order to position the jib with respect to the main boom, a tensioning member is provided extending between the crane housing and a curved extension guide connected to the jib.

A marine knuckle boom crane includes a crane housing which is rotational relative to a pedestal about a vertical rotation axis and a knuckle boom assembly attached to the crane housing. The knuckle boom assembly includes a main boom, the inner end of which is connected pivotably about a first horizontal pivot axis to the crane housing; and a jib, the inner end of which is connected pivotably about a second horizontal pivot axis to the outer end of the main boom, wherein the jib is pivotable at least between an extended position in which the tip extends mainly forward from the main boom, and a folded position in which the jib is folded back, essentially parallel along the main boom. In order to position the jib with respect to the main boom, a tensioning member is provided extending between the crane housing and a curved extension guide connected to the jib.

A self-propelled vehicle used to lay pipe sections within trenches located on sloped terrain, and a method for using it, including: an undercarriage carrying a vehicle chassis and capable of climbing sloped terrain; a rotating platform which can be maintained level relative to the sloped terrain; and a boom with an angled boom head, capable of using two independent winch cables to lift and position individual pipe sections having differing lengths and diameters. The vehicle may be used to sequentially lift two or more pipe sections, one at a time, and to swing and position the pipe sections in a trench, end-to-end.

A self-propelled vehicle used to lay pipe sections within trenches located on sloped terrain, and a method for using it, including: an undercarriage carrying a vehicle chassis and capable of climbing sloped terrain; a rotating platform which can be maintained level relative to the sloped terrain; and a boom with an angled boom head, capable of using two independent winch cables to lift and position individual pipe sections having differing lengths and diameters. The vehicle may be used to sequentially lift two or more pipe sections, one at a time, and to swing and position the pipe sections in a trench, end-to-end.

A crane includes a boom and a derricking mechanism, wherein: the derricking mechanism includes a linking device connecting one end of a guy line to a distal end of the boom; the linking device includes a joint connected to one end of the guy line, and a support device provided on the distal end to support the joint so as to locate the joint at a position away from the back surface and opposite to the ventral surface; and the support device includes a holding member which holds the joint, the holding member allowing the position of the joint to be selectively changed to a plurality of different positions in a first direction perpendicularly intersecting an axis of the boom and a rotary axis of the boom.