I have a couple of comments regarding this thread.
1. Testing spansets by using them to pull cars is a: not satisfactory, and b: possibly subjecting them to shock loadings for which they are not designed and thereby rendering them useless and possibly very unsafe.
2. The picture posted in this thread is labelled incorrectly.
The bottom of the picture does indeed show a spanset 'choked' around the bottom cord of the truss. The top half however shows a spanset in a 'wrap' position around the top cord. This is done to make the truss more secure and stable, allowing more finite positional adjustments.
3. Anyone wishing to find out more about rigging or suspension within the live production industry should read the following two publications, which though not finite, provide an excellent basic knowledge base for rigging.
An Introduction to Rigging in the Entertainment Industry
Chris Higgs
Rigging for Entertainment: Regulations and Practice
Chris Higgs
both are available via amazon or from
www.etbooks.co.ukjust remember, Assumption is the mother of all fuck ups, and rigging is not something to be taken lightly.
And for those of you in the UK, Working at Height Regulations come into force later this year.