| Added on 30/12/2011 | Article |
Moving Trees with the Tree Spade
By Chris Skellern (2002)
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The 'tree-spade' is a term used to describe a mechanical excavation device capable of lifting out trees from the ground in a simple operation. The machinery is hydraulically powered and consists of a number of blades which are curved and angled so that when closed, they fit together tightly.
Tree Spades come in many sizes to suit differing applications. They range from small, 3 bladed tractor mounted spades ideal for nursery work, right up to heavy weight, road going systems capable of lifting larger semi-mature trees.
The following photographs were snapped by Terry Marsh as he supervised the removal of four trees from Southampton City centre.
Terry's Comments:
The site is the 'Above Bar Precinct' in Southampton. This was part of the redevelopment which included the new shopping centre. The London Plane in the picture was located in one of three raised beds. The tree was being moved prior to the demolition of the planters. The area was then repaved and semi mature Acer rubrum planted by Civic trees. I cannot recall where this one was relocated to but it was probably to one of the open spaces within the City (political correctness to comfort the rate payers that the trees were not being destroyed).
A ramp is first constructed next to the raised bed to allow the vehicle to get close to the tree.
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The spade is lifted from the chassis and the cradle carrying the four blades opened.
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The cradle must be carefully located around the stem.
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Once in place the cradle is locked shut and the blades positioned at equal distance from the stem.
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Each steel blade is driven hydraulically (with incredible force) into the soil.
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The blades meet-up to form a steel capsule which contains the tree rooting system in an undisturbed plug of soil. Many roots are of course severed which is why the size of the tree-spade must be selected to suit the tree size and its planting environment.
The tree is then lifted from the soil in a single operation and stored on the vehicle.
Branches can be tied for transport purposes.
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The remaining hole!
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A similar hole at the tree's new location will have been prepared by the tree-spade in advance using the same method.
The lifted tree can now be transported directly to the empty hole and planted by reversing the above operation (by first lowering the spade into the hole, and withdrawing the blades).
The advantage of this method is that the lifted tree with its plug of soil should fit perfectly into the pre-excavated hole.
All photographs courtesy of Terry Marsh, Southampton.