US crane and heavy lift company Bigge has issued a short sales video that contains more information on how its new 4,000 tonne AFRD 125D heavy lift crane is designed to work.
The unit is designed primarily for heavy lifting in applications such as nuclear power station construction and uses a twin boom pivoted on a support trolley similar to that employed by the ALE, Mammoet and Sarens dual boom ring type cranes. The big difference is that a large part of the crane is cast into the ground, including the track/ring and the 3,000 tonne counterweight.
The benefits of this is that a large proportion of the crane’s ‘footprint’ remains open to site traffic, effectively reducing the dedicated space required. In order for this to work of course it needs to be possible to carry out all of the lifts on the site from the single location.
Another benefit is a significant reduction in the amount of shipping required. However ground preparation is substantially more extensive.
Bigge says that the 125,000 tonne/metre 125D, will take a 1,000 tonne load out to greater radii than most other cranes on the market. Although no specifics have yet been published.
The company also says that the new crane has been designed with lower ground bearing pressures, higher tolerance for lifting in windy conditions and higher hoist and slew speeds.The company says that the design concept can be expanded to around 7,000 tonnes.
A GPS tracking system is incorporated to assist with load positioning and all lifting operations are performed by a single operator. Bigge is currently planning two projects for the AFRD concept in 2011.
This is yet another example of what is essentially a heavy lift crane rental company designing and producing its own heavy lift solution rather than depending on products produced by the traditional crane manufacturers.
The AFRD design has some clear advantages for certain applications, although it may not be so well suited to others. Any big power station project, is likely to have its own concrete plant and excavators on hand to produce the special foundation for this crane which could yield a saving over the shipping and stuffing costs involved with the container type counterweights used by other modular big lift cranes. It will of course also free up a huge amount of space.
The video shows trucks almost passing through the crane while it carries out a lift, while the speeds involved make this a relatively safe manoeuvre, you can imagine that many safety officers will make the area an exclusion zone during lifts. But given that these big cranes spend most of their time waiting the area will be free for a good deal of the time.