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PLANKING CONCERNS

(Part 1)

Greg Meyer
greg7118@uneedspeed.net

PLANKING ... I have several thoughts on planking – some of which I must have read somewhere – but questions that keep haunting me whenever I get to the stage of planking. The major concern I have is in establishing planking bands. In email communications with Robert Giles (who said your models you displayed at the Washington Ship Modeling Club are excellent and who is writing a book, which will address how shipwrights planked the hull). Robert Giles uses the word “liners” – specific individuals who sole responsibility is determining these planking bands; I’m under the impression that this specific area is a very unique profession and takes an education in such to become an expert. So there must be a discipline with probably some art – but still a discipline – which we can apply to our modeling skills:

- It is my understanding that each band incorporates planks of the same widths, but planks in different bands might be of a different set pf widths;

- It is also my understanding that planks in the bottom band incorporate strakes of varying widths – some very wide (garboard and broad strake);

- It is also my understanding that planks were steamed so that they could be bent edgewise as well as length wise;

- It is also my understanding that planks were tapered (width as well as thickness) to fit into the rabbet;

- It is also my understanding that planks fit into the keel rabbet without any beveling to the plank edge;

- It is also my understanding that planking incorporated both joggle planks as well as stealers;

- It is also my understanding that the planking layout was documented before planking even started (or wood ordered);

- It is also my understanding that butt joints follow the given rules we have used thought the planking discussions;

- It is also my understanding that the bows planking entering the bows rabbet almost level, with the planking having just a slight upward trajectory at the very bottom (avoiding the dreaded Viking look);

- It is also my understanding that planking should minimize the lateral twist on the plank (in fact there should be not lateral twist at all);

- It is also my understanding that the planking should follow along the hull at places of the same slope (no twist will be put on plank at these locations);

- It is also my understanding that places of “inflection” – where the hull curve changes from clockwise to counter clockwise (or vice versa) should also define a hull line;

- It is also my understanding that we determine the number of planks/widths using the largest space in each planking band – so, if the largest space occurs at the stern for one band, this is the area to be used, not always at midships;

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Pictures above take from Dodds and Moore’s book: Building the Wooden Fighting Ship.

These are some of my general concerns. Specifically to the Constitution, Ben Langford provides a very detailed layout of planking. It looks beautiful – but how did he come up with the planking bands (four in all and 9 strakes per band)? On his diagram, all the planks are of the same width in each band, including the tapered widths at the rabbet! And guess what – he didn’t have to use any stealers or joggle planks! I know in the real world, our models will not be perfectly symmetric, which would throw some variation into the planking scheme of things. Should we strive for a layout without joggles or stealers?

And has anyone gone to the Constitution and counted the planks and observed where the “lines” are on the ship?

Ben Langford’s drawing (Constitution plans)

I have some concern using proportional dividers – which measure a straight line distance between two points – when in fact the distance we are measuring is along a curve. Thus we should use this device with care; in fact using a strip tick on paper or masking tape to take the measured distance and dividing the distance into the number/size of planks at specified bulkheads/frames would be the way to go.

I have some concern about beveling plank edges so no gap forming between planks, which gives a nice fit – but this will reduce the area covered, thus throwing off our numbers and widths.