Largest mobile crane completes bridge lifts
21. June 2006 | Comments (0)
Rigged with a 65 metre main boom, 43 metre back mast and almost 400 tonnes of counterweight, the AK680 removed a total of four bridge sections each weighing between 170-260 tonnes.
The AK680-3 linitially set up on the east (Middlesbrough) side of the river and lifted the first two sections overnight before moving to the opposite side of the river and lifting the remaining two sections a week later.
Working at a radius of 54 metres, each section was lifted from the old bridge, put down alongside the crane and then demolished using excavator mounted hydraulic breakers.
The reconstruction of the bridge will start with new supports in the river, ready for the new deck to be installed later in the summer.
The Ak680-3 is scheduled to be back on the job in three months to install the new sections and again three months after that to remove more of the existing bridge.
The crane is owned and operated by the UK arm of Belgium based transport and heavy lifting specialist Sarens. Sarens UK is ideally situated in Middlesbrough just three miles from the site.
"There were several reasons for using a truck crane rather than a crawler," said Sarens project manager Paul Weston.
"The primary reason is that the Gottwald is based at our nearby depot and also a truck crane is much easier and quicker to rig/derig and this was paramount with just two lifts each side of the river."
Although now more than 20 years old, the 1200 tonne capacity crane has recently been totally refurbished.
The unit was purchased new by Scotts in 1980, it was then taken over by BET and rolled into J D Whites heavy lift fleet based on Teesside. Whites became Grayston-White and then Grayston-White & Sparrow within BET. After Rentokil took over BET, the company became Initial. Sarens then purchased the Initial heavy crane divison, which included the AK680.
The unit travels and works all over the world and has been on contracts as far afield as Thailand and Argentina. Sarens UK has a larger unit - a Demag 9600 which has a lift capacity of 2000 tonnes, but this is currently on a two year contract in Kazakhstan. The next largest mobile crane in the UK is thought to be the 600 tonne Terex Demag TC2800 delivered last year to McNallys.
Arun Sahni, project leader for the client, the Highways Agency said: "This is a very significant part of the work on the replacement of the bridge. The crane that will lift out the existing sections is being supplied by a local Middlesbrough company so this is a real red-letter day for the area.
In all four sections of the existing bridge were replaced, the actual lifts taking place between midnight and early the following morning. The bridge was fully closed during the actual lift for the safety of drivers and also the workforce involved with the lifts.
The new section of the bridge will be completed and open to traffic in the Autumn.