I'm a pretty fit 54 year old and have no trouble rigging my boat single-handed; indeed, I have no option as I mostly sail solo on it.
I take a few precautions, using baby-stays to steady to mast in a cross wind, and a block and line on the pulpit to help pull up the mast, or hold it temporarily midway as I change my footing from cockpit seats to cabin top.
But really, it's a one person job - just like an Ultimate. It's one of the many attractions of owning and rigging an 18-footer, as opposed to a much larger TY.
Cheers,
Geoff
Investigator 563 'QUMBU'
Geelong, Victoria, Australia