Transporting kayaks, small boats, sailers or aluminium fishing boats up to 3.6 m (12 feet) can be strenuous work any time the terrain becomes any more challenging than level paving or short grass. Most times, boaters merely need to move the boat a short distance from a summer home or storage to the lake or waterway where they will launch. A homemade boat dolly you can push by hand or quickly hitch to a lawn tractor makes easy work of moving portable watercraft around.
Boat dolly wheel strategy
The boat dolly consists of a 1.8 cm (3/4 inch) diameter stainless steel axle with two polypropylene/rubber, 2.5 cm (10 inch) diameter, pneumatic wheels for small boats up to 91 kg (200 lb). The wheels should have plastic insert bearings to preclude corrosion. The axle is held to the crossbeam by four 7.5 by 10 by 2.5 cm (3 by 4 by 1 inch) thick blocks of UHMW polythene with 1.8 cm (3/4 inch) bores to hold the axle. The blocks also have two vertical 1 cm (13/32 inch) diameter holes for the stainless steel hex head bolts that connect the axle to the crossbeam.
Cross beam and support beam structure
The crossbeam is a 70 cm (28 inch) long section of pressure-treated 5 by 15 cm (2 by 6 inch) wood stud that is drilled in four places along its length with eight 1 cm (13/32 inch) holes to receive the four UHMW blocks that mount the axle. Space out the blocks evenly along the crossbeam. Before mounting the axle, bolt another 70 cm (28 inch) long piece of pressure-treated 5 by 15 cm (2 by 6 inch) wood stud with the 15 cm (6 inch) dimension being vertical to the top of the crossbeam. The top of this beam should be cut out with a scroll-saw to accept the boat's bottom shape towards its stern. Top the cutout with strips of 10 cm (4 inch) wide black poly plastic garden border edging to prevent scratching the bottom of the boat when it is on the dolly. The support beam should rest directly above the axle line on the axle crossbeam so that weight forces are transmitted directly through the first crossbeam to the axle. Use both construction adhesive and six diameter lag bolts 10 cm (4 inches) long through the crossbeam into the vertical beam. Then mount the blocks holding the axle and fasten with the eight stainless-steel 9 mm (3/8 inch) hex-head bolts.
Longitudinal tractor beam
Use a 3 m (10 foot) length of 3.7 cm (1 1/2 inch) diameter fence post galvanised pipe to form a longitudinal draw beam. It should have a V-block of the UHMW towards the front to support the pointed front of the boat's bottom. It should also have a T-bar handle on the front end to pull or push the boat, and a 1.5 cm (5/8 inch) hole for the tractor's tow bar. Connect it to the rear dolly assembly with 5 by 5 cm (2 by 2 inch) aluminium angle brackets. Also bolster this with diagonal supports made with the same aluminium angle. Connect these to the outer axle support bolts for additional lateral strength.