Monday 14 October 2019

Centre Plate (the final job before launch)


Of all the many materials and fittings required to build this boat, I did not for one minute expect that the supply of the centre plate would be a problem, I contacted several companies inviting them to submit a quotation and received a very mixed response. It seemed that they could supply the plate cut to profile but were unable or unwilling to drill the holes or machine the edges, some never even bothered to reply. To obtain a quote for the machining was a real challenge, citing excuses about handling the weight or just submitting a silly price to make me go away, no one really wanted the job. Out of frustration I decided that I would undertake the drilling and machining myself and placed an order with the most accommodating company to have the 25 mm thick 316 grade stainless steel plate cut by laser to a DXF file supplied by the architect. When I turned up to collect, it was loaded into the back of my pickup with a fork lift.

The plate is very heavy at around 100 kg and I was handling it by myself, I therefore decided to keep it low down to the floor on a pallet and blocks then take my bench pillar drill to the plate. I created the rounded profile on the forward edge by grinding with an angle grinder fitted with a ceramic grinding disc. The chamfer on the aft edge I machined using a milling machine in a friend’s workshop, I blended in the end of the chamfer again using the angle grinder. The centre board case is very tight, prompting a concern that the shackles connecting the blocks might chafe the sides of the case and cause wear, allowing possible water ingress into the plywood. I therefore decided to machine a 5 mm rebate either side of the plate around the anchor points to compensate for some of the thickness of the fittings, I then used Allen key shackles as opposed to the conventional type to further increase the clearance.


Set up for drilling on the barn floor


Clamped down on the milling machine bed ready to machine the chamfer


The machined rebate to minimise the projection of the shackles


The finished article ready for installation

Installing the plate into the boat proved to be a challenging operation. It became apparent that the whole assembly would not feed in from above so it had to go in from beneath. The boat had to be moved back on the trailer cradles to give clear access to the centre plate case which was partly obscured by the beam axle of the trailer, I then jacked up the boat as high as possible from a position just aft of the case opening. The plate was slid under the boat on timber battens then reared vertically on its edge whilst attaching the hoisting blocks, shackles and line. I then raised the plate into the case hauling on the installed tackle plus an additional lifting rope passed through the pre-drilled handling hole, lining up and inserting the pivot pin proved to be easy, an unexpected bonus. Because of the extended clearance between the keel and the ground, I was then able to carry out a test run lowering and raising the plate to check that everything was in line and working as intended.


All that remains is to cap and seal the centre plate case, carry out some further improvements to the rigging and she’s ready for launch. 

Monday 7 October 2019

Sails and Rigging



Because of headroom constraints I have previously been unable to raise the mast, but now since moving the boat outside and after much anticipation, the time has come. The standing rig is simple, comprising of a fore-stay and two shrouds which I have had made up to Francois drawing. Raising the mast was easy and quick, with one lifting from a position standing in the cockpit and another pulling forward on the fore-stay. Only small adjustments were required to get the whole assembly set firm and true. Now she really looks like a sailing boat.

In addition to the mainsail, the sail plan gives the option of two jib sizes and a balloon jib cut as an asymmetric spinnaker. Initially I have decided to have the larger of the jibs made but thought that perhaps have the spinnaker made at a later date. I chose a local recommended sail-maker of many year’s experience. Throughout this blog I have endeavoured to be completely open and honest regarding thought process and construction decisions. Regretfully I have to report that following my discussions regarding the making of the sails, I allowed myself to be convinced  by the sail-maker to deviate from the plan and use a modern sail cloth instead of the recommended ‘clipper canvas’. I now fear that I may have made a mistake, perhaps after the passage of time this regret may prove to be unfounded, either way I will inform of how I eventually feel about this and their performance. The sail-maker also made the berth cushions at the same time.


The mainsail laid out in the sail loft

There is a surprising amount of work in making up halyards, sheets, reefing pennants etc. plus the fitting out of hardware. During one calm day, I hoisted the sails to enable me to iron out any problems and improve the rig before hitting the water, this proved to be an exciting moment. I have gone for the option of a furling jib using a traditional Wykeham- Martin furler which runs beautifully. When hoisted I noticed that the fore-stay did not run parallel to the jib luff narrowing towards the head. Whilst this did not interfere with the jib when furling, I decided to rectify this detail by designing a shaped hardwood spacer block fitted to the fore face of the mast head, just below where the fore-stay loop pulls against the cleat on the aft face of the mast. 

When raising the mast from horizontal, there was a tendency for the top loop of the fore-stay to jump from its locating cleat on the aft face before hoisting tension could be applied, I therefore solved this by designing and making a stainless steel retaining cap to hold the loop into the shaped profile groove of the spacer block, this has negligible visual effect and has proved to be an effective solution.


The mast head spacer block showing the stainless steel retaining cap


Preparing to raise the mainsail for the first time




For some time I mulled over the problem of how to transport the mast, spars and sails to minimise the set up time for regular launching. I arrived at the conclusion that all rigging should remain fixed to the mast and secured along its length using cam straps to prevent slapping and movement whilst towing, this will allow for a quick and simple erection with only three shackles to secure the shrouds and fore-stay. To support the mast horizontally on the boat, I designed and constructed a cradle which attaches to the aft face of the tabernacle by bolts and wing nuts, a gallows frame set aft on the cockpit floor supports the mast towards its head and straps hold the mast assembly securely in place. The boom and gaff remain attached to the main sail which is flaked over the boom and enclosed securely by a purpose made sail coat. This will be transported by removing the bottom panel of the companion way to allow the whole assembly to span between the cabin and the cockpit. The jib is simply furled and stowed in a purpose made bag. At the end of the season I will remove the sails and stow away for the winter folded into sail bags. I have also constructed a gallows frame to provide support when attaching the boom goose neck to the mast band.

I began this blog by giving a brief outline of my background and introduced my father who instilled in us the pleasure of boating. During the Second World War he served in the RAF for four years in Egypt and during his down time as a detraction from the carnage being undertaken at that time, he sailed his small wooden boat by the name of Bunty. I had always intended to call this boat by the same name and had initially referred to it as Bunty II; however I never really connected with the idea of using a two after the name. During a stroll on a local beach at low tide, I noticed a boat called Sheila B and immediately had a light bulb moment and thought that’s it, assuming my dad’s boat as Bunty A, I will call mine Bunty B, a much nicer name with the added attraction of tripping of the tongue.