Eye witness report by Richard L.Krabbendam (Heavy Lift Specialist)
On the 28th of May 2014, ALE Heavy Lift launched its newly developed 800 tons Mega Jacking Tower. This innovative jacking system is very much alike its bigger brother the ALE MJS5200, with a lifting capacity of 5000 Tons per tower.
There obviously was a need for a more compact and efficient jacking system, so ALE took up this challenge and after a few years of development the new 800 tons jacking Tower was launched today.
With a Lifting capacity of 800 tons and a jacking stoke of 550 mm it is half the jacking stroke of the much bigger MJS5200, but it can work in combination with it. The min. building height is only 1200 mm and normal building height is 1800 mm.
The first project will be executed near ALE’s Breda home base in the Netherlands next month and involves the jacking up and replacement of a 3000 tons bridge across the Amsterdam Rijn canal, near Amsterdam
The base of the jacking tower consists of two major 1200 mm high steel girders connected to each other in which at each end a 250 Tons jacking cilinder is fitted. The jacking casette consist of a steel frame which are inserted from only only side and jacked up by 4 cilinders in synchronous mode. When a full stroke is reached a set of steel locks is hydraulically pushed underneath the the bottom jacking casette and the pistons are retracted and a new jacking casette (1.5 T) can be inserted, whereafter a new jacking stroke can be executed.
In this way the load can easily be raised to a height of max. 25 m. Weighing of the load can be done easily as well, by inserting calibrated loadcells on top of the jacking cilinders at the base and execute a weighing procedure, whereafter the loadcells can be removed and the jacking operation be continued.
A jacking speed of 1.5-3 m /hour can be reached up to a max. height of 25 m. Up to a max. of 20 jacking towers can be controlled from a central flightcase control box.