1st test - 2 poles and loads
To prove the concept design had been correctly interpreted by the engineering team at SSL, a trial erection of the steelwork took place at Peterborough Showground. Two poles were erected with two bale rings and a single (3 piece) 30 metre long truss.
The metalwork was sent to site in bare metal with no hot dip galvanising, which was a good job as the 30 metre truss needed additional braces to prevent lateral shift under full load.
A total of 36,000 kilos UDL (uniform distributed load) was suspended from the truss with a further 5,000 kilos from each bale ring to simulate the real world loads when the structure was eventually erected.
Unloading
First lift of a Valhalla kingpole.
Jade Deeling doing his thing.
Dave Freeman in charge of loading the trusses for the first test. He was one of the great TentMasters of the world, and is much missed.
2nd test - 6 pole structure
Martin Crick supervising the first lift of the 6 pole.
One of the crew getting a little enthusiastic, note NO PPE! No harness! Rudi Enos stood on the tent to take the picture.
From the first lift, the membrane shape was perfection, as can be seen, the side guys are slack and have no weight on them, the A frames are leaning out and gently tensioning the roof.
The first test used standard ratchet webbing straps, there were later changed for all steel tensioners.
The roof 30 minutes after first erection, perfectly tensioned, webbing subsystem clearly visible without the covers.
It defines a new paradigm for portable structures.
References
1. Guinness World Records, Guinness Superlatives, 1999, London
2. Institution of Structural Engineers, 1995, Temporary Demountable Structures, Guide to Procurement, Design and Use, SETO, London, ISBN 1 874266 17 4
3. Ovesen, NK and Stromann, H, 1972, Design Methods for Vertical Anchor Slabs in Sand, Proceedings, Speciality Conference on Performance of Earth and Earth-Supported Structures, American Society of Civil Engineers, Vol. 2.1, pp.1481-1500