A pulley assembly and an installation for moving objects incorporating such a pulley assembly are disclosed. The pulley includes first and second plates disposed about a median plane. One or more sheaves are disposed between the plates. The or each sheave is carried for rotation about a respective sheave axis that is perpendicular to the median plane. A bollard extends between the plates to provides an interconnection between the plates. The bollard is shaped, whereby its dimension in a direction along a major dimension line, which dimension line that extends radially from one of the sheave axes, is greater than its dimension in a direction perpendicular to that dimension line.

A pulley block is disclosed. The pulley block comprises: first and second plates and a pulley sheave disposed between the plates for rotation on bearings upon a sheave axle that extends between the plates along a sheave axis. The plates are connected to the sheave axle so as to permit rotation of one plate with respect to the other about the sheave axis between a closed position of the pulley block and an open position of the pulley block. Each plate has, at a position remote from the sheave axis, a respective bollard formation, which bollard formations are disposed such that, when the plates are in the closed position, the respective bollard formations are in contact with or in close proximity to one another to form a bollard that extends between the plates. When the plates are in the open position, the respective bollard formations are spaced apart. The pulley sheave rotates on bearings upon a sheave axle assembly that extends between the plates along a sheave axis. Which assembly has a main axle that is fixed for rotation with respect to the first plate and free for rotation with respect to the second plate and an axle cap that clamps the main axle to the first plate, the axle cap being removably secured to the main axle.

Simultaneously oppositely rotating sheaves, or a chain fall, has a two sheaves upon a hexagonal axle. The first sheave receives a first line clockwise and the second sheave receives a second line counterclockwise. Upon turning the axle, the sheaves handle the lines oppositely. A signal unit regulates power delivered from a power unit to at least one motor. The power unit is preferably a battery or alternatively another source. The motor turns a gearbox that engages the axle cooperating with the sheaves. The chain fall includes an anti-two block per line. Preferably, a pulley has two outer plates and two inner plates on stubs with the first line in the center and the two second lines between an inner plate and an outer plate. A first plate and a spaced away second plate contain the components of the invention in compact form for usage by a crane.