The Big Top has 4 king poles, with 4 bellrings, on which the membrane of the tent is attached. The plastic membrane is then attached to the bellrings and laced to each other. These bellrings are pulled up mechanically and raise the “points” of the Big Top up the kingpoles. This tightens the whole structure above the “performing” area. The outside of the Big Top has 64 side poles which stand the roofing membrane 4.0 metres from the ground. Each of the side poles is tensioned with 5.0 tonne ratchet straps.
These big tops are reinforced with so many different webbings and strips of fabric that even if the panels were removed, the structure would still stand! Big Tops have panels stitched on or radio-frequency welded together, which radiate from a central suspension point out to the side points. These emanate from the centre, or sometimes from the King Pole, to the outside poles or Side Poles. Where any pole is placed under or through the plastic structure, all these points are specially reinforced.
This kind of structure traditionally distributes its’ surface load down heavily reinforced webbings and/or cables to either a rim band (around the outside) or eves band down the section lacings and across quarter bands. This type of construction utilises the strength of the webbing to provide massive strength down the seams, and is tensioned by a combination of pulling the structure upwards along the plane of the kingpoles and outwards towards the side poles where the ratchet straps pull outwards and downwards to the stakes that are in the ground. This system has traditionally been employed across the world for some of the largest mechanically tensioned structures ever built.
|Area (Sq M)||648 Sq m|
|Area (Sq F)||6,975 Sq ft|