Plating a Multi Chine Hull
Here we have basically two types of methods; the conventional multi chine hull and the v/d Stadt frameless multi chine method.
CONVENTIONAL MULTI CHINE
These can be classed in two categories; framed and frameless. Most multi chine boat will be build to the framed method, meaning the frames stay inside the hull as an integral part of the hull.
The frameless method means that the boat gets built over the frames (former) and removed from it when completed. This results in a very light weight hull but is a bit dicey to build, even for the professional.
For the purpose of this exercise I will use a frameless building method. The hull is the "TOM THUMB 24" and was designed by Grahame Shannon.
When the frames are set up on the strong back, start plating the hull from the keel downwards. However, it is important that you plate port and starboard side at the same time (see photo) to prevent warping.
Take note that the upper chine is "softened" by installing a flat bar to break the hard chine.
Note: This complete hull, keel and decks are built of 3mm mild steel only! Keel sole is 16mm.
The plating in an advance state of completion. Here we are busy fitting the bow and this is always the most difficult part of boat building to get correct.
Just two plates to go!
Hull lifted off the former and Eddie starts to install deck frames. This hull is actually very spacious for a 24 ft LOA, mainly due to its 3 meter beam.
A moral booster at this stage; this is actually the same hull as above at a later stage of its creation. Here she sits in the backyard and is in the process of being fitted out.
This was the authors personal boat and had the following modifications from the original design; Naca fin keel instead of full keel. Cockpit shortened a bit and the cabin top stretched considerably forward to generate a lot of interior space. Headroom was 1.85 meters under the coach roof. An 8hp inboard diesel was fitted.
THE V/D STADT FRAMELESS CONSTRUCTION METHOD
As mentioned elsewhere, this type of hull is build inside a frame rather than over frames. It is a very fast building method and I completed a 34ft hull & deck, completely welded and shot blasted and prime painted in 3 weeks flat.
1. Build the building frame exactly to the designer’s drawings and dimensions.
2. Join your plates length wise until it is as long as the boat's length, then develop each chine plate individually from the table of offsets given and cut the plates out. In this case one should have 8 developed plates - 4 starboard and 4 port side
3. Lay the two bottom plates in the building jig first. From the center of the plate’s length wise, pull the middle joint together.
Then the second sets of chine plates and so on until all the chine’s are in place.
Take note: This sounds simpler that doing it. One has to remember that this particular hull has 4mm plates and one need a lot of muscle to pull it together. Chain blocks, docks & wedges are of the order of the day, but one can pull within a working shift all the plates together.
4. Then fit the bow and the stern plates
Be sure to have ample help to manhandle the plates into the jig, as they are the length of the boat!