Roger Pellett

Beautiful work!

Roger

Ok, so the oval member is what American Shipwrights would call a Fashion Piece as its primary function was to protect the end grain of planking from absorbing moisture?

So what actually supports the stern structure other than the topside planking?

Roger

Am I correct that the oval piece surrounding the rudder port, yellow in the 3D rendering is actually a structural member tying the upper and lower hull sections together?

Roger

Woodenboat has Catspaw Dinghy kits in stock- $129 and change.

Unless you are building a ridiculously simple model like a square box, the idea of scaling up individual model parts to build a full sized boat will not work. Suppose that you have a kit that builds  a 1:64 scale model of the prototype boat.  Further assume that the kit is a faithful reproduction of the real thing (highly unlikely).  If when scaling up the parts, your measurement is off by 1/32 in, about the thickness of three sheets of paper, this variance is magnified to 2in on the full sized part.  This means that the full sized hull will have a lot of lumps, bumps and parts that don’t fit.

It is for this reason that boat builders redraw boat plans to full size and then pick the parts off the full sized drawing.  This process is called Lofting, and believe it or not before computers it was done for boats and ships of all sizes from an 8ft Dinghy to a 1000ft aircraft carrier.  Today, in shipyards, ship hulls are drawn on computer screens and part shapes are sent digitally to computer guided plate and structural shape burning machines.

Small boatyards and amateur builders without access to computers with CADD software or printers capable of printing large patterns must still loft plans (full size) to obtain accurate patterns.

If you are serious about building a full sized boat, I suggest that you purchase a subscription to WoodenBoat magazine.

Roger

Isn’t 12.8mm, 1/2in?  Then a blade with a 1/2in arbor hole readily available here in the US should fit.

Roger

Wooden Boat sells plans for a “Catspaw Dinghy,” a beautiful lapstrake full sized boat that has been successfully built by a number of first time boat builders.  They used to sell a Catspaw Dinghy model kit based on the idea that building the kit was a good introduction to building the real thing.

If they still offer the kit or if you can find one on EBay this might work for you.

Attempting to scale a model kit up to a full sized prototype is unlikely tp produce a safe well performing vessel.  When it comes time for you to build a full sized boat, invest in a set of plans drawn by a professional.

Roger

Very Nice!

I’m only suggesting use of rasps for initial shaping.  When you get close to the bulkheads, it’s time to get out the sandpaper.

Mark,

Why can’t you remove most of this wood with a half round wood rasp or one of those cabbage grater type tools?  This would generate much less fine dust

Roger

Kris,

If you are a modeler in the USA, 1:32 is an easy scale to work with as common scalar fractions directly correspond to full sized measurements, ie; 1/32 in corresponds to 1 inch on the full sized vessel.

Roger

The artistic aspect of ship modeling-  Better that they be too thin than too thick!  That’s why I prefer to turn them from brass and finish them with a light coat of paint.

Roger

If you use the system that I suggested above- plank over a form made from temporary moulds taken from lines drawing stations, remove from form and insert permanent frames, you really don’t have to loft the frames.  You can determine the shapes with cardboard patterns inserted into the hull made by the cut and try method.

Roger

There are some but much later-  Brady, mid 1800’s and Luce- 1860’s.  Nothing about rigging specifically.

The thwart supporting the mast on eighteenth Century longboats was fixed-that is secured by knees to the clamps running fore and aft inside the boat.  Furthermore, the mast is secured to the aft side of this fixed thwart.  This scheme would, therefore, not work.

Roger

If the boat were intended to be nested, oars and spars could not be stored on board.  Us Navy small boat specifications even specify that ALL thwarts for boats to be nested be removable,  and that heavy longitudinal clamps be substituted for thwart knees.  Boats were heavy, bulky objects and care was taken to cut down on the height of the boat stack to minimize the effect on the ship’s center of gravity and to reduce wind age.

Roger

Sorry I can’t be of more help.  My Naval Architecture education was in the days before PC computers and the only CAD program that I ever learned was Generic CAD and I much prefer the more tactile experience of drawing lines with splines and ships curves.  The real point is, that you do not need this “diagonal” to construct your lines drawing.  You should draw one or more diagonals check the fairness of your hull shape.

Roger

I believe that the curve from bow to stern and extending outside of the half breadths is one of the two diagonals shown on the body plan.  These diagonals are drawn by Naval Architects by measuring diagonal dimensions along the line plotted on the body plan and then plotting them on the half breadths to prove the fairness of the hull.  You do not need these to draw the hull lines but should plot your own diagonals to ensure that the hull that you have drawn is fair.

I would suggest that the other line is a true view expansion of one of the head rails.

Roger

Two thoughts,

Many of the original iron bolts in the Vasa are being replaced with duplex stainless steel ones.  The material was developed for the North Sea oil and gas business.  While not “historically correct” they will allow Vasa to be enjoyed by visitors for years to come, and when the little green men arrive in their flying saucer, i’m sure they will be able to tell from museum documentation that the stainless bolts are not original.

Maybe next time USS Constitution needs an overhaul it should be contracted to Mystic Seaport.

Roger

The US Government publishes extensive requirements vessels seeking Historic Landmark status.  One requirement involves determining the vessel’s period of historic significance and providing a plan for restoring it to that period using historically appropriate materials.  Mystic Seaport’ restoration of Charles W. Morgan is in my opinion an example of this done well.

On the other hand, despite the extensive work done on Constitution she does not reflect her appearance during her period of significance (her 1812 battles).  In particular her head structure is the ugly pre Civil War boxed in type instead of her original graceful open head rails.

Roger

If you have a Byrnes saw or equivalent, a home made taper jig is easy to fabricate.  For a straight tapered mast like those fitted on rigged ships boats a square tapered stick may be quickly ripped using the jig.  A few passes on each corner with a model makers plane gives you an octagon.  The spar may then be finished with a sanding block either by hand or chucked up in a slow turning drill.

Roger

Several thoughts:

I agree that making a good Viking ship model is a challenge, even for an experienced modeler.

A tricky part of any lapstrake construction is the point where the planking ties into the stem and sternpost.  The Vikings made things easier for themselves by erecting large carved stems and sterns with the laps carved into them.  The planking fits on to these posts and matches up to the carved laps.  A good book on Viking ship construction should show this feature.

Most lapstrake boats feature lightweight steam bent ribs sprung into the hull after it is planked.  Viking ships are different as their ribs are much larger and notched to fit the planking laps on the inside of the hull.  

A daunting for some and enjoyable for others part of scratch building is planning the method to be used to build the model.  When you buy a kit this has supposedly been done for you.  I would suggest that you attach a number of bulkheads properly spaced as well as your carved stem and sternpost upside down to a flat building board.  You then “line off” the planks using a batten as described above.  The location of each plank where it crosses the bulkhead should be marked.  The plank shapes are derived by marking the points on the bulkhead on transparent material bent around the bulkheads.

After you have planked the hull it is removed from the building board and permanent frames carved to fit the laps are inserted.  The bulkheads are not permanent.

Good luck!

Roger

Steven,

I’m sure that your guns are more precise than the ones made by the blacksmiths in the early 1500s.

Roger

Obviously, later than you are thinking of but U.S. Navy practice in the 1860’s was to stow boat oars and spars in the hammock boxes atop the ship’s rails.

Roger

Is there a similar new edition of volume I ?

Roger

Hank,

You probably already know this, but just in case, here goes.  A big enemy is going to be rust, especially in a high humidity environment like the southeast.  Rust bloom can form on unprotected steel surfaces in hours. Even in our cool summer climate with low humidity here in Minnesota (where we don’t run the AC during much of the summer) I have had trouble with rust forming on tools in my basement workshop.

I would therefore suggest that insulation and AC, or preferably a heating/ cooling heat pump be at the top of your shopping list.

Roger