This article covers the lifting and transplanting of a fully grown sugar maple tree at Myerscough College to make way for the building of a new laboratories and classroom block. The tree was listed as it was a rare specimen for England and it had to be secured for the future. The article will cover two days, 10-11 January 2002.
9 January, the tree has been prepared by excavating the root ball which has been bound by hessian and netting. to stop the roots from spreading too much and to keep a surrounding ball of soil to nourish the tree. It is now early morning on 10 January. We are expecting cranes to arrive. The crane to lift the tree will have to be so large that it has to be put together on-site
It's 8:00am. The main part of the crane arrives like this. Another crane comes with the parts for the jib and a pile of steel plates and weights.
The steel plates are placed on the ground. Legs extend from the sides of the crane so that it doesn't topple as the boom arm swings. The weights are lifted and placed on the bed of the main crane.
Meanwhile this hole is to be the recipient of the tree once moved. The College Arboriculture team have to level and finish preparations.
12:30pm - the crane is still being built. This process could take up to three hours. The packing around the rootball is checked to make certain it is secure.
The jib boom is put together on the ground. The tree (on the extreme right) has to be lifted and swung around the building behind to reach it's new spot. It has to be swung by the crane arm as there is no way the crane can lift it and then move itself and its load.
1:00pm . The pulley system for the main jib is placed between the counter weights - now at an immense weight. Not counting the weight of the motor and pulleys there are 15 weights at 7.5 tonnes each, making over 100 tonnes in all.
2:00pm. This is why all that weight is necessary, the weights counterbalance the weight of the arm of the crane plus its load when extended out to the side. The whole thing has to be able to swing freely and extend in any direction. There is another hour of setting up to go.
The Arboriculture Department have had to create a route for the chains to come vertically down the tree without being diverted by branches. Otherwise once they bear the weight of the tree the chains would snap them, leaving the way clear for the chains to jerk and risking the tree falling.
3:00pm - the chains and arm are attached to the crane. Meanwhile the job of passing slings underneath the tree commences. The rootball is so heavy that it must be lifted from below not by the trunk or branches. The slings are like very large straps attached at both ends to chains either side of the tree.
4:00pm and it is going dark again. Buildings within the distance the tree might fall are evacuated - my office is the dark window on the first floor.
4:30pm - it seems that the tree and soil around the rootball may be heavier than the straps can cope with. An air gun (a form of very powerful hairdryer!)) is used to blast away loose soil from the the rootball.
5:15pm - the tree has been moved but not lifted yet. Rocking motion allows the air gun to be used underneath. A short break is taken whilst staff go back into affected buildings to collect their belongings and leave the college at the end of the working day. It gives me chance to take two more shots from my office window!
9:00am 11 January. During the evening yesterday it became apparent that the tree would not lift because it had been planted over an old existing tree stump and the roots had entangled with the root system of the stump.
9:15am. The roots were cut away during the night and after waiting for daylight for a final visual inspection, the tree was lifted within ten minutes.
The crane then simply swings, moving the tree carefully past the Fitzherbert Brockholes building towards its new home.
This is a fairly slow process, no one wanted the tree to lose balance by moving too quickly!
9:20am - the tree swings over the hole prepared earlier. Lots of relayed arm-waving tells the crane operator how to respond - he is sitting in his cab quite a way away!
In the end manpower is required to push the rootball into the exact spot than at a signal, the crane driver lowers the tree gently into its new home.
Once the soil and gravel mix has been shovelled around the rootball so that the tree can be confirmed as safely planted, the Arboriculture team once again climb into its canopy to secure steel cables to hold it steady and to fit a complex hose system around it with tiny holes that for the next two or three weeks will create a mist of moisture, the tree's very own microclimate to ensure it does not dry out and die. Over twenty years later the tree remains healthy and growing.
