Don, everything was explained several years ago in the minutest detail on the Rover forum on Outerlimits and the 'Members Vehicle' forum on lr4x4.com ,but you need to be a member there for some BS reason to access the members section, so it can't be linked to.
Rather than repeat it all here,probably best you call in sometime and lay under the truck for a while and it will all become clear.There's no magic or rocket science involved. just straight forward, simple, basic and cheap (because i'm a pauper) engineering.
The front tyres are on back to front because this is a tool as well as a toy, and in winter I regularly winch a lot of trees out of the ground and then drag them in reverse gear to a central fire site for burning.
The rear springs are transit fronts. the rear drop shackles are made from old scrap army Landy 2 stage jacks. the forward end of the spring attaches to pivoting drop down hangers, just visible in your blown up photo.Torque reaction and for/aft axle location is controlled by a 'Tripod' (one link) pivoting from the t/case crossmember.Lateral location is by the leaf springs,ie even during articulation there is always at least one forward spring hanger in the laterally rigid position, thereby precluding the need for a rear panhard rod,the geometry of which, would be real crap at those angles anyway.
The front suspension linkage is what's called a 3 link plus panhard rod arrangement. there is a top link above the diff to control torque reaction.
Incidently, that ramp is sitting on loose top soil and was surmounted in rear wheel drive with difflock disengaged.Had the ramp been longer it would have gone further.So anyone who criticises suspension flex as a **** because they see dangling ,drooping wheels as having little or no traction are not necessarily correct.That may be the case with many examples, but not with this one.Offroad stability is another consideration.Imagine how unstable that vehicle would be by locking the suspension so it couldn't flex and then driving the front wheel to the top of that ramp.As it was it would take the strength of 4 men lifting on that front wheel to topple the truck over.
There was so much happening at the trials on Sunday that I forgot which vehicle it was that several helpers had to prevent it from falling on its side due to instability caused by insufficient articulation.I would have liked to study that in a bit more detail because the same cross axle obstacle merely caused most other vehicles participating in the event to lift wheels and/or lose traction.
As to Dianas point about the points score formula for ramp competitions taking into account wheelbase and track widths. We don't do RTI scores because it is meaningless in the real world. Cross country terrain doesn't give a stuff or make adjustments for how long or wide your wheebase is. Your vehicle either has the ability and stability to overcome the obstacles or it is winch and tether time.
According to my protractor, an increase in trackwidth of 10'' gives an increase of approx 7'' vertical height of the upper wheel if the axle was tilted to 45 degrees.Or only 3'' with the axle tilted at 22 degrees, which happens to be the angular limit of the standard rear A frame ball joint.
Bill.
