Folding or knuckle-style cranes are sold by DEL and made by Effer and Maxi Lift and, as the name implies, they fold up and open, much like the knuckles on your hand. These cranes are very compact with a high power-to-strength ratio and take up very little room on a truck frame or body allowing room for a dump box or flat bed to be mounted as well. The design of the crane also makes it very useful when picking up objects close to its base and then extending straight out to unload making it a popular crane for construction companies, monument companies, and landscapers.  When in operation the crane unfolds and a hydraulic boom with a hook on the end extends out to a desired reach and lifting capacity to lift and place a load off the truck or onto the truck body.

Determining the size and capacity is really quite simple as there are generally only 3 criteria that must be met when choosing a crane.

1 - what is the maximum weight of the objects being lifted?

2 - what is the required reach that the load has to be extended to?

3 - what truck and body will be used to carry the crane?

With regards to #1, DEL carries electric and hydraulic cranes capable of lifting small objects up to 700lbs all the way up to a staggering 138,000 lbs at 12' reach. The closer the object to the centre of the crane base the heavier the load that can be hoisted by the crane.

Regarding #2, the lifting distance ranges from 3' right up to a whopping 165' with a 1145 lb load which can be dropped onto the top of a building or structure or even over the roof of a house.

Lastly the truck and body that will carry the crane has to be a suitable size to handle the stress and leverage created by a load being extended away from the truck. The truck frame has to be sufficiently strong enough to resist bending or twisting and the truck itself, heavy enough to handle the weight of the body, crane and the load being carried. A truck can easily be flipped onto its side if it has not been chosen correctly.

All hydraulic truck mounted cranes are equipped with outrigger legs that extend out and down to the ground to stabilize the truck and load, but some are also available without legs such as the smaller Maxi Lift (electric hydraulic cranes).

DEL has engineers on staff that will calculate payload and truck stability to insure the correct package has been put together and will advise if the truck is not correct for the job.

Finally there are a myriad of attachments and options available for truck mounted hydraulic cranes such as brick and stone grapples, log grapples, pallet forks and rotators that can turn a load to the precise location for precision placements.

Remote cable and radio signal controls are popular options that allow the operator to stand close to the load and control all functions of the crane allowing them clear vision and the ability to stabilize a swaying load.

If you are interested in some entertaining videos go on YouTube.com and type in Effer Cranes.