Jib Crane Outlet » Wall Mount Jib Cranes

How Big Can a Jib Crane Be?

Tad Dunville — Tue, 14 Jul 2009 20:03:30 +0000

In theory, one could order an enormous jib crane of any capacity or reach. In fact, the principles of the jib crane are employed on oil rigs and in harbors on what is commonly known as a “whirly crane” (pictured), a crane that rotates as a jib crane but travels as a bridge or gantry crane would.

But there is a practical limit to the industrial jib crane. After all, most factories and warehouses where jib cranes are installed do not have the same space configurations as a harbor. A harbor has little land to mount a bridge or gantry crane on, but lots of air space to let the top of a jib crane swing around. A factory has little air space because of the roof, but the entire factory has a floor underneath it to mount a crane.

The jib crane then is available up to fifteen tons rated capacity and twenty feet reach. Many times we find the jib crane is really only practical up to five tons rated capacity and twenty feet reach, but that is a game-time decision. If your project manager notices the design of a crane is approaching the threshold for design effectiveness, he or she will mention such an issue and make suggestions.

Wall mounted jib cranes are available to twenty feet reach in the cantilever format, and thirty feet reach in the tie-rod format. Again, it’s important to ask your project manager what solution is best when approaching the limits of the design.

Jib Crane Standard Configurations

Tad Dunville — Thu, 25 Jun 2009 19:50:21 +0000

The jib crane is a ubiquitous tool for any factory, and almost all jib cranes come in one of three configurations. The main three configurations can be adapted to almost any situation with a little thought, saving the customer money and time over specialty products. Jib Crane Outlet sells hundreds of jib cranes every year and very few are outside the main group. The three main configurations have two sub-groups: Floor-Mounted and Wall-Mounted jib cranes.

Floor Mounted Jib Cranes. Although there are about five types of floor-mounted jib crane, only the free-standing floor-mounted jib crane is truly important. This is a jib crane with an upright mast, a running beam or boom (interchangeable terms), and a concrete foundation (supplied by others) to allow the jib crane to stand upright on a factory floor without any other support. In fact, if a concrete foundation were properly applied, a jib crane could work on the top of a mountain or the bottom of a sea floor without any other support. The free-standing floor-mounted jib crane typically has a design range up to 25’ reach and five ton rated capacity. Most dimensional needs over fifteen foot reach are better served by a gantry crane or bridge crane.

Wall Mounted Jib Cranes. Most wall-mounted jib cranes are actually mounted to a steel building column that would be behind the wall if an industrial building were really a living room or office. The wall-mounted jib crane can be a tie-rod jib crane, where a tie-rod mounted to the wall above the boom and tied off to the far end of the boom supports the weight, or the wall-mounted jib-crane can be a wall-cantilever jib crane, where a beam is cantilevered out without a tie-rod to support the load. As a rule of thumb, the tie-rod jib crane is chosen when maximum lifting height is not as important as economy or price. A wall-cantilever jib crane is more expensive but can also allow the load to be lifted fifteen percent higher because the tie-rod does not need to be mounted above the crane.

Thrust and Pull – Wall Jib Loadings

Tad Dunville — Tue, 16 Jun 2009 14:00:46 +0000

Thrust and pull are the forces exerted by a wall-mounted jib crane on the wall. Most of the time the phrase “wall-mounted” actually means the jib crane is mounted to a steel building column as if that building column were a wall. A standard steel building column is engineered to support the weight of the building roof as well as anything that hangs from that roof: lights, ducts, fans. Typically these extra items are light weight and inconsequential to the building design. However, when one mounts a heavy jib crane capable of lifting 4,000 pound loads, the building column must be specifically designed or adapted to support the jib crane.

Jib Crane Thrust and Pull

Who can design or adapt a building column to support a wall-mounted jib crane? Typically this person is an architect, engineer, or general contractor with engineers on staff. A safe rule of thumb is to have a Professional Engineer or “PE” stamp the drawing showing the modification or design.

So what exactly is thrust and pull? All wall-mounted jib cranes have a beam and a beam support device, usually either a tie-rod or vertical-mounted mast. There will be two hinges to allow the jib to swivel 180 degrees. One hinge is always at the place the beam meets the wall. The beam is the running beam for the hoist/trolley. The other hinge is always where the support device meets the wall: either the end of the tie-rod or vertical mast. The tie rod is above the beam, while the vertical support member hangs below the beam, like an inverted “L”. Because the load is hanging off the beam, the beam is like a lever being pulled by the load.

If one envisions the beam as a lever being pulled down, it’s not hard to imagine the top hinge is effectively fighting to pull out of the wall, while the bottom hinge is effectively fighting to go thru the wall. Pull and Thrust. See the drawing. The wall or column must be engineered to withstand the pull on the top hinge and thrust on the bottom hinge.