Raft

1. The Main Structure.

• The Raft is comprised of 4 main pipes each approximately 39 feet (11.5m) long, and the raft s measure 20 feet (6m) meters wide
• The pipes are blue water supply pipes.
• The pipes are made of Polyethylene.
• The specified designation for these pipes is SDR21 (PE 100) and they are designed to operate at a pressure of 8 BAR.
• This particular designation of pipe is formulated to be highly resistant to cracking even at these internal pressures.
• The diameter of the pipe is 710 to 714 mm externally.
• The average wall thickness is 35.7mm.
• The average weight per meter is 71.1 kg.
• The pipes have 40mm end caps welded on by a certified welder.
• Each pipe has a conical fiberglass, with foam fill, “collision bow” clamped to it. This structure will be sacrificial, as the end cap behind will provide the watertight bulkhead required.
• There are 14 cross pipes
• The pipes are made of Polyethylene.
• The specified designation for these pipes is SDR21 (PE 100) and they are designed to operate at a pressure of 8 BAR.
• The diameter of the pipe is 310 mm
• The average wall thickness is 15.75 mm
• 7 of the pipes are blue water pipes
• These have butt-welded ends to the same standard as the main pipes.
• These pipes will carry the water for the crossing.
• The remaining 7 pipes will be yellow gas supply pipes.
• These will have capped ends.
• The connections between the cross pipes and the main pipes comprises of rachet strap lashings with a 5000kg breaking strain.
• There are 2 independent straps at each join.
• There are wooden saddles at each connection to reduce twist at the connection.
• There is anti-chafe protection at all relevant points.

2. The Deck

• The deck comprises of 1’ by 6” timbers spanning approximately 3’ on center.
• The deck is lashed to the cross tubes with 5mm pre-stretched rope with a breaking strain of 600 kg.
• The deck has non-slip “sanded” paint applied.

3. The Rig

• The rig will comprise of a wooden mast 11.5 meters long
• The mast sits on a wooden railway sleeper lashed to the two central main pipes with 12mm pre-stretched ropes with a breaking strain of 2800 kg.
• There are three independent ropes per connection to give double redundancy.
• The mast is stayed with 14 mm pre-stretched rope with a breaking strain of 3800 kg.
• The mast diameter is approximately 250 mm maximum tapering to 150 mm, minimum.
• The yard lies at approximately 26 feet above the deck.
• The yard is approximately 6 m long.
• The yard is attached to the mast with a conventional yard truss.
• There is a conventional square sail below the yard.
• The sail area of the main will be approximately 37 square meters, (400 square feet).
• The sail will be of Polyester and the weight of cloth used will allow the sail to withstand 40-knot squalls.
• The reefing on the main sail is conventional slab reefing.
• There is a mast step.

4. The Steering

• There are two types of steering.
• The first is twin rudders at the stern. (Ed. They broke)
• There are also traditional Guaras (centerboards) at the corners of the raft.
• There will also be two oars on board with mounting points amidships to assist in maneuvering.

5. The Accommodation.

• There is one accommodation shelter on board.
• It is a modified animal shelters made of wood and corrugated stainless steel.
• Facilities include cooking, communication, navigation, living and sleeping for 4 persons.
Hammocks have been added to accomodate crew of 5 on Caribbean to Bahamas trip

Trials of this water-pipe system were made at Melbourne, Australia, with a raft 20-ft by 12-ft. These proved the general idea’s practicality, and also concluded that such a raft equipped with several guaras could almost be sailed into wind, and certainly travel within an arc of about 150 degrees. It was also discovered that a single length of rope, if attached either to the port or starboard outer pipe, could itself alter steering ability by some 10 degrees.