Sunday, June 23, 2013

Setting the hulls LEVEL and Parallel

I had selected a spot in my garden that is relatively flat for the purpose of assembling my catamaran. The drop in gradient for 30 ft is about 2 to 3 inches. I guess I will be quite happy to apply chokes to the hulls  to find the final level. The boats water line would have been a perfect ref point but the reference is inside the hulls on the bulkheads and by now its markings would have been faded to the point of being invisible. That is the problem of taking too long to build one's boat!
I have a friend Dr Nik who is building his own house ( a portion of it) with his bare hands and he has the Laser leveller. He came over and worked out some numbers.

His laser equipment shows that there is a gradient of about 3 to 4 inches between the two hulls.


  His final solution is in order to ensure perfect level, some sort of a platform to house both the hulls must be constructed. Yes...that is the perfect solution but I am not prepared to spend so much time and money to get absolute perfection. I also remember that most Wharram designed cats only use rope to tie the hulls to the beam.


I resorted to the traditional way of using the pendulum bob and the leveller. Now one most important primitive equipment that I used was based on  the principle that water finds its own level. So a small transparent hose was purchased and I measure the hulls from a datum to ensure that the hulls are on a same  level and  perfectly up right.
 Several of these mason's levelling ruler were placed in various parts of the hulls

 A car jack came in handy to raise and lower the hulls slightly so that some pieces of wood or planks could be inserted under the hulls
 Finally my mosaic builder friend Ah Sang came over with his electronic leveller to confirm my work is acceptable. This time he came just before dark so that we can see the laser markings better. His theory is that he will mark several poles all around the boat with the same level. Later if I want to check the level all I need is a string pulled between the points of the same level


One other function of his laser equipment is he can also check whether both the transoms are in line or not. My son Alwin and my nephew was around so I had some extra labour to push the starboard hull 3 inches forward.

Gypsy Final Asembly Instructions

On the plans for the Final Assembly of the Gypsy 28 Catamaran it was just staed:

"Set up hull so that CL are 4100 MM apart
Ensure hulls are parallel and that diagonal distances are equal
Brace well, Fit aft beam and knees
Join cockpit to Cuddy as shown
Cut Mast Beam holes in Cuddy
Glue and Glass cockpit to aft beam "

Haha.. it sound so simple but I have been spending a lot of time wondering how to execute this.
Probably it will take me the whole of this year to complete the assembly.....The items are heavy and I could no longer work alone most of the time.


Sunday, June 2, 2013

Repositioning the Gypsy pieces

 The hulls had to be repositioned to a relatively flat surface for the final assembly of the pieces.. I had also liaised with the "future" crane driver so that the boat once completed can be craned out of the house. There were some construction workers just across my house and I managed to talk to their boss for the use of some muscles to lift the hulls and the cuddy to its new position.6 workers came and with a lot of shouting and cheering we managed to move the two hulls and the cuddy (the cuddy was blocking the way initially)
 Some smart guys says we needed straps to lift the hulls but  we substituted that with some ropes and a rubber hose.
 With the two hulls in position we took the aft beam and position it right at the back of the hulls.

The cuddy was then brought in to its new position. The reason why I had to place the cuddy here is that I have no maneuvering room once the beams are attached to the hulls. At this position I think I can use rollers to roll it forward and aft when needed to.

 I now have an empty nest! This boat shed id vacant! It is just like having grown out kids moving out of the house!. Next....preparing for the assembly!