A small dock that would float on a river whose water levels changes dramatically throughout the season. The dock needed to be light enough for 1 person to disassemble and carry away for the winter or when a major storm was predicted.
A small number of inflatable docks are available for $600-$1000 but didn’t seem durable. Docks on wheels are also available if you provide the decking but again seemed expensive for what you get. Many people have posted their approaches to homemade docks but none met my requirement. An experiment with an old aluminum ladder failed as it had too much flex over the span. Instead, a dock that could be disassembled easily into 5 pieces was designed and turned out to be inexpensive.
2 blue 55 gallon barrels with plugs ~$40
7 8’x 5/4″ treated decking wood ~ $32
2 8′ 2″x4″ treated ~$6
4 cambuckle tie downs ~$10
8 6″ lag bolts and washers ~$5
7 36″ 2×2 baluster treated ~$7
1 8′ 2×2 treated $8
exterior decking screws
4 8″ dock cleats – $16
The 2×4’s are the outside of the frame with the 36″ ballusters making up the cross members. The balusters are spaced so that the barrels are straddled. The balusters may seem undersized but they are light and the lag bolts are really providing most of the load strength. The barrels are strapped to the frame allowing them to be transported separately. The decking is separated into 2 sections to be easier to carry. The dock is tied to the shore with ropes and a locked chain to reduce theft. A removable ramp is used to get to the dock to but discourage people from the river coming ashore when nobody is in the area.
The dock is somewhat latterly unstable. It is usable but expect movement if someone stands on one side. In this installation, a ramp connected to shore improves stability. Ballast weight could also be added if desired.