Sometimes a full overhead crane is too much for a site, be it a low roof, limited steelwork, or closed overhead space. This range of equipment fills this gap.
JIB CRANES
A jib crane consists of a single arm which can pivot around its mount. The mount can be wall-attached or floor-mounted, and the arm can pivot around a full circle or only part of one. Typically, wall-attached mounts will rotate around a half circle while floor-mounted posts will allow full rotation. JIB cranes can usually only service one workstation, but the cost difference between a wall-mounted jib and an overhead crane system is quite substantial.
LIGHT CRANE SYSTEMS
A light crane system consists of a less bulky, modular, and sectional aluminum track. A hoist can traverse the length of the track and is moved along the track by the user. Unlike other systems, these modular systems are meant to be manipulated, and can be operated while under load. Due to this feature, they can quickly and easily move parts between workstations and so are very common on production lines.
Davit Cranes
With davit cranes, a vertical post fits into a permanent base, and a lifting arm fits (and lifts) slides onto (and off of) the post. This property allows davit cranes to be situated at a loading bay, or maintenance point, or any other place where permanent cranes cannot be justified. This property allows davit cranes to be lifted anywhere occasional lifting needs to be done safely. Socket-mounted davits also function in confined space and rescue operations. In rescue operations, davit cranes provide a lifting point at the edge of a hatch or manhole (where lifting points do not otherwise exist) and is what facilitates safe entry.
Portable Mobile Gantries & Shearlegs
Mobile gantries feature a freestanding (and wheeled) A-Frame. This property allows mobile gantries to be rolled into a workshop, used, and rolled out again. A mobile gantry is perfectly suited for a workshop that requires occasional crane lifts, and cannot justify a permanent crane (which would take up valuable headroom). Shearlegs also function on the freestanding principle and are an evolution of an older rigging method. The older method originated from two or three (rigging) legs being laced or pinned together at their top to form a triangular shape, and lifting tackle was hung from that apex. That shape has barely changed, because there has never been much to improve on it. The shape is stable, requires no foundation, and can be constructed to any height the job calls for.
Van & Lorry Cranes
Originally designed for the front or rear of the truck, a loader crane enables the truck cab to load and unload its cargo from the delivery point wherever a forklift or fixed crane is not available — say at a rural delivery, a domestic installation, a yard with no locomotives of its own, or a yard where the only equipment is a van. A transit-sized van can carry a large variety of loader cranes. Heavy-duty units can be permanently mounted on articulated lorries. The crane’s arm reach and lifting capacity are equally important.
Just because equipment is portable does not mean it is lightly regulated. Davit cranes, mobile gantries, and lorry cranes mounted on a truck bed require the same rigorous inspections as fixed overhead cranes because they lift the same weights and pose the same risk if they fail.