Assembling the grid
The completed laths are laid on the supports to form the first layer of the grid.
With the four layers of laths arranged, the grid is fixed in place by clamps at every intersection point.
The clamping assembly consists of a galvanised steel plate with steel pegs protruding on both sides which are inserted into holes drilled into the innermost laths in order to exactly locate the intersection. Plates on either side with four bolts clamp the whole assembly together. The two outer laths are not drilled as they will need to move slightly to accommodate the curvature of the structure.
Lowering the gridshell
March 2001 – The process begins….
19th March 2001
Two weeks on and the edges of the gridmat have been lowered by up to three metres and the characteristic curved shape is beginning to appear.
April 7th 2001 – Halfway down …..
Over 60 tons of scaffolding have been removed at this point and the sides of the gridmat are supported by jacks positioned at angles to remove excessive cantilever loading on the structure.
April 20th 2001 – Finally down.
Minor adjustments to the shape will be carried out before the addition of shear blocks for strengthening and fixing of the shell to the curved panels at the edge of the deck.
Fixing the gridshell
June 5th 2001
Prior to the assembly of the gridshell, marine ply fascias were attached to the floor and the ends of the Glulam beams. Angle brackets were then attached to either side of the Glulam beam ends and five holes drilled through the fascias aligned with holes in the brackets. The following picture shows the position of the brackets and the holes.
Where the laths of the grid overlap the fascia, the gaps between the laths have been filled with additional sections of lath giving a solid section four times the depth of the individual laths.
Blocks have been laminated at each point on the fascia where a bracket exists inside the fascia. A further layer of marine ply matching the inner fascia is added to form a sandwich consisting of two layers of marine ply and four thicknesses of lath. The sandwich will be secured with bolts through the ply and laths and the whole sandwich will be bolted to the brackets at the end of the Glulam beam forming a fully rigid fixing at the base of the structure.
The next picture shows how this process has been completed for the end frames, the small bolt heads fix the sandwich and the large bolts will be driven through the sandwich and the end frame and secured on the inside.
The following picture shows the view from the outside of the frame.
The following picture taken 22nd June shows the process completed.
The final picture in this series taken on 22nd June shows the additional laths that have been introduced at half metre centres where the areas of maximum stress will occur in the gridshell; horizontal or vertical laths have been fixed at each grid intersection point to lock the triangulation into its current position so that when the jacking system is removed the gridshell will retain its current shape.
The wooden cladding will be attached to the horizontal laths and the vertical laths will support the polycarbonate glazing. The first vertical panels of cladding can be seen together with the first frame of the structure to support the ribbon roof
Ply cover plates are inserted to tidy up the junction of the gridshell and the deck.