A telescoping jib of a mobile crane with telescoping sections that telescope inwards and outwards from a jib base casing, and a guying system for the telescoping jib having at least one cable extending between a guying frame and a fixed point by a guying support and is anchored by guying supports, where each guying support comprises a holding mechanism for the cable. A method for guying a telescoping jib of a mobile crane in which at least one cable is anchored between a guying frame on the telescoping jib consisting of a jib base casing and a plurality of telescoping segments and a fixed point on the telescoping jib, and the at least one cable is guided by means of at least one guying support supported on the jib base casing head or a telescoping segment head of the telescoping jib.

A crane vehicle capable of preventing another vehicle from coming into contact with a tip end portion of a boom when entering an intersection includes a controller that detects an obstacle on a lateral side of a tip end portion of a boom by using left and right cameras when the vehicle enters an intersection or the like. When it is determined that a detected obstacle may come into contact with the tip end portion of the boom, the controller drives a brake device to stop a crane vehicle, and causes a speaker to output a warning sound. When it is determined that there is no risk of contact with the boom as the detected obstacle stops, or moves away from the crane vehicle by turning left or right, or passing an intersection, the controller releases the driving of the brake device to enable travelling of the crane vehicle.

A marine knuckle boom crane includes a pedestal and a crane housing rotational relative to the pedestal. A knuckle boom assembly is attached to the crane housing and includes a main boom and a spreader type jib. A hoisting system includes a first departure sheave and a second departure sheave on the jib, and a third departure sheave mounted to the main boom or to the crane housing. One or more winches drive a first, second, and third cable which are each connected to an object suspension device and each pass via the first, second, and third departure sheave, respectively, to the respective winch. The first, the second, and the third cable together define an inverted pyramid which diverges upwards from the object suspension device when handling the object.

The invention relates to a tower crane having a tower which carries a jib, from which a hoisting cable runs off, wherein a guying system is provided and runs, at least in part, along the tower and is spread out, by means of guy supports, in a direction transverse to the longitudinal center plane of the crane, this plane running through the tower and the jib, wherein at least one pair of guy supports which are spread out in a V-shaped manner are articulated on the tower, between the lower end of the latter and the jib.

A portable winch and method of use is shown. One advantage of winches shown includes an ability to lower a boom or boom sections into limited access exit pit for winching operations such as pipe bursting. Sectional boom designs shown provide the ability to easily raise and lower a boom large distances without the need for a single long boom. Selected winch designs shown include flexible inserts between the boom and the winch frame that help resist damage from unforeseen shifting of the device during operation. Designs and methods shown also include multiple pulleys on a boom end unit. Fasteners are shown that reduce build up of debris.

A portable winch and method of use is shown. One advantage of winches shown includes an ability to lower a boom or boom sections into limited access exit pit for winching operations such as pipe bursting. Sectional boom designs shown provide the ability to easily raise and lower a boom large distances without the need for a single long boom. Selected winch designs shown include flexible inserts between the boom and the winch frame that help resist damage from unforeseen shifting of the device during operation. Designs and methods shown also include multiple pulleys on a boom end unit. Fasteners are shown that reduce build up of debris.

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 guide structure 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 guide structure connected to the jib.

An improved building access system includes a turntable having an upper surface and a lower surface, a main tower attached to the turntable's upper surface, a boom tower pivotally attached to the turntable and disposed so as to form an angle with the main tower, and a balancing tower also pivotally attached to the turntable and also disposed so as to form an angle with the main tower. It also includes means for changing these angles between the main tower and, respectively, the boom tower and the balancing tower, and a cathead pivotally attached to the end of the boom tower which is opposite the end attached to the turntable. The inventive apparatus also includes pressure sensing devices located and disposed so as to measure the pressure at each mounting point where the main tower is attached to the turntable, along with one or more leveling rods disposed so that, as the boom tower is raised upwardly and the angle between the main tower and the boom tower decreases in value by an associated amount, the angle between the cathead and the boom tower decreases in value by the same amount. The turntable may further include at least one support arm configured so that the bending forces experienced by the turntable are transferred to a larger diameter support structure. The invention also includes an elongated beam member which is especially useful for forming box beams, which member has a pair of symmetrical planar side elements which are perpendicular to each other and which are also connected together by a diagonal element.

An improved building access system includes a turntable having an upper surface and a lower surface, a main tower attached to the turntable's upper surface, a boom tower pivotally attached to the turntable and disposed so as to form an angle with the main tower, and a balancing tower also pivotally attached to the turntable and also disposed so as to form an angle with the main tower. It also includes means for changing these angles between the main tower and, respectively, the boom tower and the balancing tower, and a cathead pivotally attached to the end of the boom tower which is opposite the end attached to the turntable. The inventive apparatus also includes pressure sensing devices located and disposed so as to measure the pressure at each mounting point where the main tower is attached to the turntable, along with one or more leveling rods disposed so that, as the boom tower is raised upwardly and the angle between the main tower and the boom tower decreases in value by an associated amount, the angle between the cathead and the boom tower decreases in value by the same amount. The turntable may further include at least one support arm configured so that the bending forces experienced by the turntable are transferred to a larger diameter support structure. The invention also includes an elongated beam member which is especially useful for forming box beams, which member has a pair of symmetrical planar side elements which are perpendicular to each other and which are also connected together by a diagonal element.