Why are we building a carbon punt? It's simply a question of weight. We are hoping to construct the world's first carbon fibre punt, that will take two people, fold in half for ease of transportation (on land), and go as fast as possible in the water. We have been designing this since early 2011, and built a wooden prototype to prove the concept during 2014 and 2015.
In September 2010, Mike Hart MBE and Dom Harlow punted the length of the non-tidal Thames, to raise funds for an RNLI appeal. The 125 mile route from Lechlade to Teddington was completed in 47 hours, 38 minutes and 8 seconds, with both crew members punting day and night. The craft used for this trip was a wooden '2-foot' punt, kindly loaned by Dittons Skiff and Punt Club.
The prototype was constructed between June 2014 and July 2016, in the workshop of a good friend of ours (who very kindly tolerated our presence). Working just in the evenings and weekends, the scrap wood that had been donated by Chorus Group, and the floorboards from a freegler in Hoddesdon, were all carefully crafted to create the vessel pictured above. The hinge mechanism was also fabricated from some scrap aluminium and a chopping board, and Aerocatch have helped us to hold the two halves together with a pair of their superb Aerocatch3 fasteners. If you click on the Gallery menu, you can see more of the actual construction, and a time-lapse film as well.
So, after putting the wooden prototype together, we waterproofed the hull for the marine trails. Our friends at West System International have very kindly donated all the epoxy resin we need to cover the hull, and we topped this off with a bright coat of polyeurethane varnish in a fetching yellow. The graphics were then applied with external high performance vinyl, and it all looks quite dazzling when out on the water.
The protoype has been as two indentical halves, due to space and transport constraints. Each section is 4.5 metres long and, when built in wood, is still very heavy.
...that hinges in the centre...
The joint, or hinge, in the centre was designed by Dom to hold both sections rigidly in place. It is made from 3mm aluminium plates, a titanium 'hinge' plate, and Aerocatch 3 fasteners. It also has a 2.5mm thick neoprene gasket that seals the hull.
...with a carbon fibre pole...
We also wanted to lighten the pole that is used to propel the vessel, and have used a 35mm diameter carbon fibre tube, with a wall thickness of 2mm. After adding the 'shoe' and 'cap' to the pole, the overall weight is 1.25kg. the ends of the pole have also been sealed with spray foam to keep the water out when immersed.
...and fits on a car roof rack
Just to prove it can be taken anywhere, here it is loaded onto the roof rack of our Zafira, after the successful maiden voyage.
After punting the Thames in 2010 rekindled Dom's love for the sport, it was always a case of 'we're going to need a lighter boat', so a project was started to build a carbon fibre punt. Following on from the initial design, a wooden prototype was constructed - just to prove that the boat would float. A novel feature of the design is that it made from two identical halves, and can be split apart for easy transportation. This was caused by two factors; 1 We don't have a trailer big enough to carry a one piece boat and, 2 We don't have a workshop big enough to build it in one piece either!
This is the method we are thinking of using to create each half of the carbon fibre hulls that will make up the punt. We want to make the joint sections first, followed by the storage drawers and bow plates. We will then glue these together with carbon spars, forming the framework to support the structural foam that adds thickness to the hull. The knees (internal strengthening ribs) are made of foam blocks that will allow us to use a single piece of pre-preg mat when lining the inside of the hull. the outer hull coating is also one piece, but the bow section will be constructed separately from foam rubber - to absorb impacts during voyages. Finally the logo will be self adhesive vinyl film.