FEB 2015 TECHNICAL MEETING

THE  BUILDING  OF  ‘CHARLOTTE’

Our speaker for this meeting was long time ABBA member Klaus Sussenbach who presented to us on the building of his Norwalk Island Sharpie “Charlotte”.

Picture1

“Norwalk Island Sharpies (or NIS’s as they are known) were designed by Bruce Kirby in the US and are one of the North American style sharpies that are rigged as cat‐ketches with un-stayed rigs and centre boards. Klaus launched his boat in 1998, having commenced construction two and a half years previously, in 1996, and has covered a lot of sea miles since. The vital statistics of Charlotte are as follows;

  • Length – 26 feet
  • Draft – 0.4 m of water, board up, and a generous 1.8 m, board down
  • Rig – Cat rigged with two masts
  • Sail area – 31.6 sq metres
  • Ballast – 500Kgs
  • Design reference – refer website www.nisboats.com

Klaus commenced the presentation by ‘tabling’ a very impressive 1/10th scale model of Charlotte which he had built before he started building the real thing. The model allowed us all to get a good initial appreciation of both the overall external features of the NIS design as well as the internal construction viewable through cutaway sections of the model. This also highlighted the initial challenges of converting the plans from imperial to metric which is Klaus’ more natural measurement system.

 Picture3Picture2

 

 

 

 

 

 

Whilst working through the conversion process, he collected together the tools and materials needed for the project. In this regard, he recommended good quality sanding (torture) boards with two good handles. Other tools included a special sander made up for getting into corners, joggle sticks and circle guides for working around curves and of course the boat builders best friend – lots of clamps. He also made up the teak plugs and corner pieces and the aluminium window surrounds. Klaus explained how he created a triangular cross section fillet from an initially square timber in a process that allowed the fillet to be clamped to the main component ahead of gluing.  Finally, a major recommendation was the purchase of a plastic welding gun which he used to heat the epoxy overflow glue which could be removed easily using a blunt chisel at about a 22 degree angle. I’m sure this one little gem of information could save us all many hours of clean up time.

With this introduction, Klaus moved to a photo presentation that traced the construction of Charlotte from the model to the launch and sail. Your editor will try to capture this in words and pictures in the following pages of this newsletter.

Readers should note that no boat building project is ever ‘finished’ and Klaus has addressed a number of modifications to Charlotte along the way. These include mast raising systems and a change from aluminium masts to carbon fibre, a change from a swinging rudder to a dagger one, installation of a forward collision bulkhead, modifications to the bunks and installation of water tanks at the companionway and current modifications to the centerboard.

Melting the lead external ballast into a 150mm x 75 mm mould with a brick

Melting the lead external ballast into a 150mm x 75 mm mould with a brick

Each bulkhead was fully made up in the workshop before any assembly proceeded

Each bulkhead was fully made up in the workshop before any assembly proceeded

Bulkheads assembled on the building frame, chines and gunwales in place and the centrecase being lowered into position. Klaus noted that the chines were fabricated from two pieces of timber

Bulkheads assembled on the building frame, chines and gunwales in place and the centrecase being lowered into position. Klaus noted that the chines were fabricated from two pieces of timber

 

Using a planer angle attachment and straight edge to prepare plywood scarp joints<br />

Using a planer angle attachment and straight edge to prepare plywood scarp joints

Bottom and side skins have been completed and the whole hull glassed over. The aperture for the outboard motor and the centre board slot can be clearly seen. The centerboard is constructed from jarrah and oregan and has a lead shoe.

Bottom and side skins have been completed and the whole hull glassed over. The aperture for the outboard motor and the centre board slot can be clearly seen. The centerboard is constructed from jarrah and oregan and has a lead shoe.

Picture9

 

Picture10

 

 

 

 

The cast lead ballast was carefully lowered and then bolted through the upside down hull, faired in with jarrah blocks at the ends and then filleted and glassed over to became integral with the hull structure. The overlapping heavy sail cloth seals for the centre case were also fitted.

Klaus sanded the hull with the long boards previously procured and used an air supplied breathing apparatus during this process.

Klaus sanded the hull with the long boards previously procured and used an air supplied breathing apparatus during this process.

 

The big moment arrives and the finished hull is rolled over using a lay shafts and pulley technique in the workshop<br />

The big moment arrives and the finished hull is rolled over using a lay shafts and pulley technique in the workshop

 

 

 

Framing for the cabin and superstructure takes shape. Klaus pointed out that he maximised the painting of future inaccessible areas during this phase of the project.

Framing for the cabin and superstructure takes shape. Klaus pointed out that he maximised the painting of future inaccessible areas during this phase of the project.

The first of two curved skins that form the cabin top is glued into position over the completed frames. The cabin top is two layers of 4mm ply with the second layer vacuum bagged on. Note the cabin sides are already completed including window cutouts.

The first of two curved skins that form the cabin top is glued into position over the completed frames. The cabin top is two layers of 4mm ply with the second layer vacuum bagged on. Note the cabin sides are already completed including window cutouts.

Picture15

Cabin, decks and cockpit construction complete and fit out well advanced. Hatches matching the cabin top curve have also been constructed and fitted. Hatches were fitted with brass strips for the sliders. The cockpit is self draining and the companion way was made narrower than plan and the bulkhead doubled up to accommodate lockers accessible from inside the cabin. Seating comprises teak strips on top of the cockpit lockers.

Filling and sanding proceeds on the hull, deck and superstructure and primer is applied.

Filling and sanding proceeds on the hull, deck and superstructure and primer is applied.

 

The topsides glisten following application of the gloss topcoats. Klaus used two pack after initially finding that single pack paint was not hard enough.<br />

The topsides glisten following application of the gloss topcoats. Klaus used two pack after initially finding that single pack paint was not hard enough.

 

 

 

Picture18

Picture19

 

 

 

 

 

 

A really professional internal fit out with a great deal of room for the size of the boat — looking forward in the view above and looking aft in the view to the right.

Picture20

What a sight — Charlotte complete on the trailer and ready to launch.

Picture21

Picture22

 

 

 

 

 

 

Klaus has developed three mast raising and lowering systems starting with the one on the left and now using the one on the right. In the process, he has converted from the original aluminium masts to much lighter carbon fibre ones.  Talk to Klaus if you need to know more detail.

Picture23

The design of the trailer for Charlotte commenced along similar lines to the boat building project with a scale model to fit the boat model.

Picture25Picture24