School for Shipmodel Building School for model ship building

[Dave Stevens (Lumberyard)]

and now the mini lecture on model building

When you look closer you might notice a difference in the model as built and the drawings. Here is the drawing by Chapelle



The red area is quite narrow with a slight flaring as it approaches the stern



The model as built is wider and a slightly more flare toward the stern so why is that?

 

[Dave Stevens (Lumberyard)]

" Both models and ships are "shaped and refined during the building process." Thus, it always was and always will be. When it comes to plans, "accuracy" is a relative term. At the end of the day, it's always the craftsmanship that determines if the parts fit well enough. There used to be a saying: "A good framing carpenter works to the nearest eighth of an inch and a good finish carpenter works to the closest sixteenth of an inch, but a good a shipwright works to the closest ship."

Any professional craftsman who uses drawn plans for any purpose lives by the universal rule that "Measurements are never taken from the drawing, but rather always from the notations." In fact, many draftsmen printed a standard caveat on all their drawings saying just that. This is a rule that is widely ignored by modelers who commonly do the exact opposite

For some, the most important thing is the carpentry skills and their result, while for others it is the concept the carpenters tried to follow, with varying degrees of success in practice. Personally, I see no reason to oppose one to the other, because there is no conflict or contradiction here.

I believe that there is no such thing as true precision or false precision Rather, precision either exists or it does not, and to a varying degree.

In a nut shell what is being said plans are the concept and starting point. At some point a builder stops taking measurements from the plans and builds to the model. It is well known "the hand of man" or the "creeping thousandth" prevents a perfect model built to exactly the plans. Not saying sloppy building is acceptable what is acceptable is the model not being built to the thousandth of an inch as drawn on a set of plans.
As case in point the reason the last planked section at the side is wider than drawn started with the stern construction. It started out in the correct place but as the stern was built it creeped upward when compared to the drawing. keep in mind you are looking very close the differences are in the thousandth but they do add up thus the term creeping thousandth



the stern is built on the structure and that is where it all started, placing the transom pieces slightly different from the drawing. This resulted in the deck ever so slightly higher at the stern.



does it matter is an opinion if you building for strict competition and the judge has a set of calipers and he is measuring from plan to model you may lose a point or two because the model is not exactly built to the plans. But if your building for your own personal satisfaction and it looks good and it is close enough your good to go. The general public viewing the finished model and never seeing the original drawings would have no idea what is right or wrong or close enough.

 

[Dave Stevens (Lumberyard)]

A top view shows a space between the frames and at the stern this is where the rail stanchions will go. These rail stanchions are separate from the frame top timbers because that can be replaces if broken. If they were the top timbers od a frame planking would have to be removed and the top of the frame repaired. The stanchions and railing are a delicate part of the model and will be the last thing added.
So next will be moving on to deck planking

 

[Dave Stevens (Lumberyard)]

It is time to install the cap rails

i use cardboard templates for just about all the parts before cutting wood



a tool you really never hear about and that is a pair of scissors, making cardboard templates requires a clean sharp edge. You have to be able to cut a very thin sliver and not rip, bend or crush the edge.



i will just do one cap rail because the procedure is the same for all the sections starting with a rough shape i will draw a pencil line along the bulkhead inside and out




Drawing the inside line is difficult because there is little space between the sap rail and deck so i cut off the tip of a pencil and held it with a clamp.

 

[Dave Stevens (Lumberyard)]

This is where a good pair of scissors come in handy, you want to cut a clean even edge outside the pencil line.

 

[Dave Stevens (Lumberyard)]

Tracing the pattern to the wood you want to draw a fat line around the cardboard template. I do this with a pencil that i sanded to a flat end. This gives me a fat wide line around the edge.



The reason for the extra wood is so i can give the cap rails there final edge along the bulwarks.

 

[Dave Stevens (Lumberyard)]

Another way to do the cap rails is to cut a rough shape



glue the rough pieces to the top of the bulwarks.



Then sand the edges to a thin overhang of the bulwarks. Sanding this way is quick with a sanding disk on a Dremel tool to bring the cap ril down close then finish it by hand sanding.
The wood being used for the cap rails is Walnut which goes well with the Cherry planking

 

[Roger Pellett]

Tolerances: You are correct, real wooden ships could not be built exactly in accordance with the design drawings. Their hulls were complex three dimensional structures that had to be “sculpted.” During this building process, subtle variations would occur that could affect the finished vessel. This may account for differences in sailing performance of different ships supposedly built to the same design. And it may also be why historians have so much difficulty figuring out which of the several contemporary lines drawings show the “real” shape of the Schooner Yacht America. Lines recorded by the British in a dry dock are slightly different from drawings from other sources.

In his interesting book, Industrializing American Shipbuilding, historian William Thiesen explains the technical changes required by the transition from wood to iron ship building. Where wooden ships had been built on the building ways by artisans, iron, and later steel ships now required 1000’s of drawings to precisely show construction details. A rivet cannot be driven though two pieces of steel plate if the holes do not line up exactly.

This is not to encourage sloppy workmanship. Ship designs have what historians call “defining characteristics.” A knowledgable observer looking at a ship model should be able to immediately see the unique characteristics of whatever design its builder has chosen to build. Or as Bob Cleek has posted “a compelling impression of the real thing.”

Roger