Andy,
I have seldom seen such an interesting post so galvanised by indifference
Thames barges are flat-bottomed, square-sided and bluff ended, so their displacement is huge.
I'm sure there is a good marine architect term like prismatic coefficient or displacement block factor or something; I would say they have a shape factor about 85% of a brick of the same dimensions.
My offspring-controlled TSB was/is to be 8 foot long and 2 foot wide - we did a quick check and this would clear his structural bits (as they were then). The main hatch is to be completely removable - to form a cockpit, and the keel/drop keel if required then lies between the lower legs.
If the plan was rectangular the base area would be 16 Square feet, (1.46M2), but it is probably 85% of that or 1.24M2 and for every 100 mm of displacement I make that 0.124 M3 displaced or 124Kg, (so it would support me if the hull is at least 200mm deep)
Angus can happily paddle a kayak standing up, so in some ways dynamic balance may be the way to go, rather than static pendulum stability.
I tentatively planned to fit motors, batteries, etc in the rear compartment, together with servos in case the skiper and ballast were not available.
If a 4 foot model TSB is 1/24th scale, then an 8 footer should be 1/12 approx making the full size about 100 foot, which seems about right
As you so rightly say,
no boom to clonk the head
On a historical note or two: There is a half scale barge in existence and working (Cygnet - last seen (by me) at Snape in spring 2007
Beautiful, but I can't get my mind round the tiller
And I have seen in a friend's book a scale TSB about 30 foot long - The pictures showed it in a landscape with narrow creeks which made me think of the Thames shore on the Kent side or possibly marshes in essex/suffolk. My guess would have been the 1930s/40s.
I wonder if anyone knows anything about her?
If mayhemmers don't: nobody don't
andrew !1949!