1. Plastic box 300mm x 500mm, wt. 1Kg empty 1ea.
(rectangular, stackable i.e some flare to sides)
2. House bricks wt. 5 kg ea. 6 ea.
3. Terracotta tile 1.5 kg 1 ea.
4. Hardwood framing timber, short billets 2 ea.
5. Plastic boxes, rectangular, with watertight lids,
filled with water 2 ea.
6. Bathroom scale 1 ea.
7. Carpenter's spirit level 1 ea.
8. Steel measuring tape 1 ea.
Item 1 represents the hull. Ballast comprises items items 4 and 5.
with a total wt. of 8.5 kg
Payload comprises item 3 and four house bricks.
1. Place payload in otherwise empty hull. Place hull in
swimming pool. Check that it is level by placing the spirit level
across the hull, supported by the gunwales. Place a fifth brick on
top of the others, but offset it 60mm. towards the side. Lift one
end of level until it is level again and measure the vertical
distance to the lower gunwale. Repeat the exercise with a second
brick beside the first one.
2. Place both of items 5 in bottom of hull, lying flat and
chocked off with items 4, to form ballast. Place payload (same as 1
above) on top of ballast. Add one, then two bricks, offset as
described above and measure vertical distance in each case, as
Next post -- results.