Aboard Creeky: nerdy

Saturday, December 6, 2014

More reading, more math, more fun!

First off, many thanks to Big Tom for extending his expertise and sharing his personal library of boatbuilding literature with me. At this point I certainly can't say that I lack sufficient boatbuilding references to figure out what I need to. The bigger problem is finding the information I need within the materials I have. Easier said than done.

Current reading list

The biggest issue I am currently trying to solve is that I am having the mast stepped (installed) and all of the standing rigging made in July/Aug of this summer and there are a lot of preparations that need to be made to the boat between now and then. The standing rigging is basically all of the "cables" (technically wire rope) that connect the mast to the hull and "ropes" (technically halyards) that allow you to raise the sails. This is not to be confused with running rigging, which is all the other "ropes" (lines/sheets) that control the sails while underway. Since the mast has never been installed I need to figure out the exact placement for it, the keel step, the deck hole, and all of the chainplates. I also need to calculate the strength required for each of these things as well as a number of other related things. These sorts of things are typically calculated well before a boat is ever built, and indeed they likely were in this case as well. The problem is that I don't have any of those calculations, all of which were made prior to my birth when the terms "Watergate" and "Reaganomics" were still in vogue.

On a brief side note, I apologize in advance for getting into nerdy boat terminology. Maybe I will devote a page to boat vocabulary someday. Until then, please continue to google terms or ask me for clarification.

Now that everyone has their boatbuilding terminology handbooks at the ready I'll dig a little deeper. I currently know about 70-85% of the dimensions I need to calculate the placement and strength of all the chainplates that connect the standing rigging to the hull. The frustrating part is that the remaining dimensions I need to figure out require an intimate understanding of the hull's displacement, righting moment, and other important design dimensions that can't be easily derived from other known dimensions. This means that I have to go back to the drawing boards (literally) to fill in these gaps.

Fortunately I had a recent major breakthrough when I was able to get in touch with Lee Creekmore's wife Abby. As the name implies, Lee is the son of Ray Creekmore who originally designed the hull of 'ol Creeky (and had the same nickname). After some digging in their attic, Lee and Abby were able to find some original blueprints for the Creekmore 45'. I can't tell you how exciting it was to lay hands on original drawings with various notes and scribbles from the design process.

Monday, March 24, 2014

Yacht Design 101 - About exactly as hard as you would think it is

Sometimes I am reminded of the fact that I'm not just working on building a funny little quirky floating apartment, but a rather sophisticated piece of engineering wizardry. Due to the limited amount of information available on Creekmore Sailboats, and mine in particular, it's not just as simple as assembly. At this stage of the game there is actually quite a bit of serious calculating, design, and fabrication required before I can take 'ol Creeky out for a sail. This is primarily in the design of the standing and running rigging (the cables that attach to the mast and the lines/hardware that control the sails). While I could farm out the whole process to a naval architect or similar expert, it would be much more expensive than I can afford at the moment. The cost of the rigging itself this summer will be more than enough to keep me broke. I feel that it will be a huge benefit to fully understand the forces acting on the boat in any given situation. This will help me to be more confident in the mechanics of the boat; but will also give me the knowledge to deal with any rigging failures down the line where I might not have a knowledgeable, English-speaking naval architect on hand.

So I'm doing the math myself. The two books I am buried in right now are "The Complete Rigger's Apprentice" by Brion Toss, and "Principles of Yacht Design" by Lars Larsson and Rolf E. Eliasson. Pretty light reading...

While I hope to to the bulk of the planning myself I will definitely get some input from more knowledgeable folks before trusting my assumptions and calculations. My friend Jesse had a great idea: get in touch with a naval architecture professor and see if they could make it a student project. Just waiting for responses now. Thanks for the idea Jesse!

Another reason I didn't want to spend a bunch of money on a naval architect is that many of the dimensions that could be designed are already fixed. The mast is 62', the boom is 18', the hull a'int changing at this point, and I already have all the sails. There's also about 10,000 lbs of lead ballast epoxied into the keel. My hope is that the bow will settle down a bit when the mast is installed, but if it doesn't I'm just going to have to deal with it and maybe add some more ballast towards the bow. Even if I went with a naval architect and they told me they would do things differently, like add a mizen mast, I still wouldn't. I am going to build the boat as Henry originally designed it, or as close as possible given the information I have. I'm getting there.

One thing that has helped is the layout drawing of the hull with a view from above and from the side (down to the waterline). This doesn't include the mast, rigging, or the keel, but I realized it was in 1/20 scale and built a 3D model using Google Sketchup. So far I've just built in the more basic dimensions, but eventually I plan to model the entire boat. For anyone that uses Google Sketchup, I shared the model in the 3D warehouse. Search for "Creekmore 45."