Frequently Asked Questions

Can you help me with some of the Jib Crane Terminology?

Anchor Bolt Load:
The total amount of force that is applied to each supporting anchor bolt; usually measured in kips.

Axial Load:
The total vertical force applied to the supporting structure. Formula: Axial load = (overall weight of the crane) + (design factor x weight of load)

The horizontal beam (track) upon which the hoist trolley travels. The “jib” of the jib crane.

Bracket Center:
The distance, center line to center line, between two supporting brackets of a wall mounted jib crane (i.e. the distance between the two wall mounting points).

The maximum live weight that the crane is designed to support. For jib cranes, the design load is based on the capacity, plus a hoist &trolley allowance (15% of capacity) and an impact allowance (25% of capacity). The allowable deflection of the crane is calculated using the design load plus the hoist allowance. Load testing can be performed to 125% of rated load capacity. Standard Gorbel jib cranes are available in capacities up to 5 tons (4536 kg).

The difference in elevation at the tip of the boom between an unloaded crane and a fully loaded crane; usually measured in inches. Our Jib Crane designs tend to have stricter deflection criteria than others in the industry.

Free Standing jib cranes require that a special foundation, usually of concrete and steel, be used to support the crane and prevent the crane from tipping over. Foundation recommendations can be found in the price pages and in the installation manual.

Height Under Boom (HUB):
The distance from the floor to the underside of the crane's boom. The minimum height under boom equals the height of the load, plus the maximum distance the load is to be lifted, plus the headroom required for the hoist, trolley, and attachments.

The vertical steel component of the jib crane which supports the crane. Free Standing jib cranes (including Work Station Jibs) have a circular pipe for a mast, Wall Cantilever cranes have standard I-beams, and Mast Type cranes have wide flange beams. Wall Bracket cranes do not have a mast.

Overall Height:
The distance to the highest point on the jib crane (should include hardware). A minimal clearance (nominally 3 inches) is required from any obstructions above the boom or tie rod assembly throughout the entire rotation of the crane.

For a jib crane, span is the distance from the center of the pivot point to the end of the boom. Note that "span" is greater than actual “working span” or “hook coverage.”

Supporting Structure:
For a free standing jib crane the supporting structure is the foundation which the crane is bolted to or implanted in. For a wall bracket or wall cantileverjib crane, the supporting structure is the wall or column to which the crane is bolted. Mast type jib cranes have a supporting structure at both the ceiling and the floor.

Thrust & Pull:
Forces exerted by a crane on its supporting structure. Thrust is the pushing (or compressive) force exerted on the structure, while Pull is the tensile force. Thrust and Pull are thus equal (but opposite in direction) to each other. The maximum thrust & pull occurs when the crane is loaded at full capacity.

Working Span:
The working span (or hook coverage) is less than the span of the crane. It is a function of the maximum hook reach and the ability to get the trolley close to the mast.
working span = (distance between trolley stops) - (hoist trolley length)

What considerations should I make before selecting a jib crane?

Considerations for selecting a jib crane:

  • type and extent of structural supports available.
  • current or future need for powered operation of the hoist or crane.
  • the characteristic and design of each crane type.
  • overall height and height under boom offered.
  • relative cost of each jib crane type.
  • the overall cost of installation.

Why are the Free Standing Jibs that sells better than the competitors?

Full Baseplate Gussets1. Full gusset base plates

Other manufacturers typically utilize open gussets which can cause a warped effect.

Benefits of using full gussets:

  • stronger base to support the crane
  • less deflection at the tip of the boom

Large Head Size2. Large head size

other manufacturers utilize a smaller head that can disfigure and damage the crane components leading to difficulty with the operation of the crane.

Benefits of larger head:

  • eliminates crushing of trunnion rollers
  • decreases deflection

Trunnion Roller Design3. Unique design of trunnion rollers

prevents cutting into the mast, eliminating the need for a wear band. Other manufacturers use smaller trunnion rollers or cams that may actually carve into the pipe during rotation.

Benefits of these Trunnion Rollers:

  • ease of rotation
  • no need for a wear band

Two types of trunnion roller assemblies are used:

  • Type 1 - single formed channel and two rollers for mast diameters of 16" or less
  • Type 2 - four rollers used for mast diameters of 18" or more