diagonal planking

[PAR]

Dan the boat is on the narrow side for a Morse style Friendship and has a much shallower hull, which is understandable considering her displacement. This draws out the WL's a bit for an easier entry and run, though she shouldn't be confused with a boat that can run much above her LWL imposed speed limitations. Draft is quite shallow at 32" with the board up, considerable with it down. Yes, it's ballasted. In fact all of her 1.3 tons of ballast is external except for about 400 pounds.

The mast is birdsmouth and will weight about 62 pounds for it's 29' length, which is only 27' off the LWL. The gaff is 31' off the LWL and the topsail yard, if used would be about 36' off the LWL.

As far as beating other Friendships, she'd do about as well in a straight line as any other, but she'll be much crisper in maneuvers, possibly a bit closer winded for better shaped appendages and less wetted area, so if it was close racing, then she'd win for handiness.

Richard, the Lord method, which I've modernized and updated a bit, is fairly clever considering when it was derived. "Naval Architecture of Planing Hulls" in 1963 by Lindsay Lord and the process was tested fairly well with everything from high speed 80' patrol craft to little 20' pleasure runabouts. In a nut shell it's a cored composite hull using a softwood strip core that's epoxied together, then covered in fabric like Vectra, Xynole, Dynel, etc. Now, I know what you're thinking and I thought it too a number of years ago, those fabrics have pretty high elongation properties and you're right, but this is the point. Lord discovered that when done over a light structure, an area can deflect and absorb loads, then return to it's original position relatively unharmed. Because of the high cyclic capacity of the softwood core and the fabric/resin matrix, you can build a lighter structure that can absorb as much energy as a heftier, but stiffer one. In fact, he was big on minimum internal framing structure, typically using furniture and bulkheads to bear loads. This is common place today, but not in the 40's and 50's when he was working on it. He used a lot of plywood in his builds and very little real carpentry, such as rolling bevels in rabbits, etc., just butter it up with thickened goo and slapped the next piece down. So, on this hull above, the scantlings seem ridiculously light, but they're not. The hull core is 7/16" with 3 external plies of Xynole and two internal plies of Xynole. The is a keel of plywood sided 1.5", there are two longitudinal frames the width of the cockpit foot well and cabin sole of 3/8" plywood and some athwart plywood forms of mostly 1/4", but not much else as far as structure except for seat and berth tops, cabinets and soles. Naturally, this is a laminate schedule best suited for bagging as the fabrics float and the last thing you want is a lot of resin.

This is long out of print and has always been a bitch to find. I found one on Amazon for $200, which is twice what I payed years ago.

[Boston]

you sure you didn't mean 42" draft, cause if you scale the 36" station grid its looking like about 40". Oh well no big deal it looks like a nice modern take on the design while maintaining the traditional appearance above which is exactly the kind a thing I think needs to happen more often than less. The traditional designs just have an appeal that cant be ignored and bringing some of em up to speed through improvements in hull shape and construction techniques is bound to be a hit with the "I'd like to build a boat" crowd. Hows the cabin head room ?

OK so I been looking around here for that cold molding book you guys recommended so long ago and dam if I just cant find it. Driving me nuts, I'm starting to wonder if I ever ordered it.

cheers
B

hmmmmm
old Daves book should be here in a few days
course with my luck by then I will find the one I thought I had floating around here somewhere.

I know which Author was meant watson.

Now I would like to know the method, not that Gerr mentioned it too (which was not new either)

PAR

thank you Paul, all clear now.

Regards
Richard

[PAR]

No it's 32", so maybe your screen has a mis-calibration, which is often the case. Using a drawing program, draw a square and zoom in so it fills the screen, then measure it. If it's not the same in both dimensions, you need to alter your screens aspect ratio, which are usually little buttons on the front or side of the monitor. It's one of the first things I do when I get a new monitor. There are also intentional non-reconcilable "errors" in the drawing, the shapes are accurate, but the drawing, if lofted would quickly cause a lot of head scratching. The draft is proportionate in profile and section.

Yes, Gerr mentions this method and has some rules covering it Richard, though his rules are a tad heavy (typically with his scantling system), especially for this system, which must be light to be worth the effort.