Thanks Roadrunner, but the T & C's are not folding as far as I can see and a bit big 'n 'eavy compared with what I am running at the moment.
I have been all through wiggle, ATC,CRC,SJS etc etc and I have actually found very few 'semi-slick' folders in the 26 x 1.3 - 1.5 range I am interested in, that will also take 85 psi or thereabouts.
The issue is not puncturing, but possible blow out/damage to the tyre itself which I understand can be a problem with the additional loading and wear and tear on tandems. Our all-up weight is probably around 23st [:0] not counting the tandem itself and before we add panniers!