Sampram - sampan based pram dinghy
The sampan dinghy is 7'9" LOA, 3'5" max beam with a displacement of 350lbs. It is designed primarily for one person but can be used to transport two. The Sampram can be rigged for sail but is primarily designed to be rowed.
I originally designed this small two sheet, pram style dinghy to test out my theories on panel development that I had previously tested at 1/12 scale. It's based on the sampan but it became my test bed and yes the panel development did work full size.
I follow Bolger's idea that the curve of the chine in profile should match the curve in plan. I wasn't overly concerned with displacement as the purpose was really to try out various schemes but with these square boats you can get a quick estimate of displacement by calculating the area of the immersed hull in profile and multiplying that by 85% of the max beam. In this case it works out to around 350 lbs.
The prototype was built without using epoxy and the hull has stood up well considering that it is stored outside uncovered and has been since it was built. The only failure was at the starboard chine that sat under a drip line from a 20' roof, at two spots the relentless drip,drip, drip broke down the cement/glue mix after a year
The construction is stitch and glue and the hull can be constructed out of two sheets of 1/4 ply plus some lumber yard 1x4. The quality of the build is up to the builder.
The prototype was built in 2009 in 12 hours. See the photo on the gallery page.
Free plans available in PDF or DWG
I originally designed this small two sheet, pram style dinghy to test out my theories on panel development that I had previously tested at 1/12 scale. It's based on the sampan but it became my test bed and yes the panel development did work full size.
I follow Bolger's idea that the curve of the chine in profile should match the curve in plan. I wasn't overly concerned with displacement as the purpose was really to try out various schemes but with these square boats you can get a quick estimate of displacement by calculating the area of the immersed hull in profile and multiplying that by 85% of the max beam. In this case it works out to around 350 lbs.
The prototype was built without using epoxy and the hull has stood up well considering that it is stored outside uncovered and has been since it was built. The only failure was at the starboard chine that sat under a drip line from a 20' roof, at two spots the relentless drip,drip, drip broke down the cement/glue mix after a year
The construction is stitch and glue and the hull can be constructed out of two sheets of 1/4 ply plus some lumber yard 1x4. The quality of the build is up to the builder.
The prototype was built in 2009 in 12 hours. See the photo on the gallery page.
Free plans available in PDF or DWG