Monday, November 2, 2015
Chine runners for flat bottomed sailboats, some thoughts.
32 years ago I owned a 21' San Juan centerboard sloop. I had bought it for $1,000.00 with the mind to clean it up sail it a bit and resell her. This fiberglass design had a long drop cast iron keel that you would hoist up with a hand crank trailer boat winch through a big hole in its trunk. I learned very quickly that this set up was a nightmare to try and stop the ingress of water into its cabin. I also learned that when you hit the bottom with this heavy metal keel it would shake the boat like you had just lost all the ocean out from under you and dropped to the sea bed. Needless to say when in anything that looked like shallow water up it went and away would we start sliding to leeward on our crabbing passage to our anchorage. I learned I would never want this set up. I sold the boat for $3,000.00 which you could still do back then. I at times owned up to 8 boats that I was buying with the mind to fix up , learn it bit and then resell. I've never lost money on a boat... Yet.
When I met and sailed with Jim Melchor on his Phil Bolger designed Mannatee yawl I got hooked on shallow water capable sailing vessels. I loved the way he could just sail about in 2-1/2' -3' of water without worry. The mizzen sail offset on the stern was so radical. Who was this guy Bolger that said you could do this and not follow convention ?
Jim sailing Alert in shallow water. The leeboard acts like a a simple long low aspect keel. It's design has been around for centuries.
Jim Melchor asked if he could finish one of his sons Bolger Black Skimmer leeboard Yawl designs in my custom boat building shop " Back Bay Boats" in Tavernier in Key Largo. Sure! After Jim launched we sailed that boat every chance we got.
I loved just watching the water flow around it's simple exterior 2x4 chine logs. Who would of thought of doing this to make it easier for amature builders. Oh yea, to hell with convention.
I owned a Herrshoff Prudence sloop at time that I had built with all matching bronze hardware. Here was a designer I could follow in my own personal life.
This boat was very stiff and fun to sail but had a wicked weather helm at times. The hull scantlings were way too light for me. The hull looked like it would not last long if not looked after carefully. In reality it did not. These boats with butt blocked plywood panels and one layer of Dynel cloth just do not hold up.
The next intresting boat I came across I had only heard about through my sailing friends Michel and Idda Little. They had built a smaller Bolger double ended leeboard cat rigged 30're. They only sailed it a very short distance from Key West to the Marquesas keys to camp out on for the winter. You could do that back in those days. They have written a great book on camp cruising small boats.
From them I heard of this kid that they had met named Matt Layden. They said he was living aboard and crusing in a 13' cat rigged flat bottom dinghy that had a cabin top. And the thing that they wanted me to know was that it had no Keel, leeboard, daggerboard or anything. They said he sailed everywhere on just the chine !
It would take many years later before Matt and I finally met up in the Exumas.
See pictures in an earlier blog.
During this time frame I decided to design and build my own shoal draft yawl. I wanted a very ocean capable boat but also very capable to really sail across very shoal waters with out the need for an engine. Between this time frame I looked up Henry Scheels keel design for reducing draft on production standard keels. The Austrailans had won the Americas cup with a wing keel.
I had seen how easy the water flowed around the Bolger 2x4s.
This guy Matt was sailing all over with just his Chines.
The boat only sails on one side of its keel at a time. The hull sides would act like a leewards low slung flat surface... Except that I could use the whole side of the boat.
I ended up putting this chine edge down the whole length of the first Hogfish design. Pete Culler in his book on Skiffs and Schooners goes on to say you should never have a hard chine boat with a protruding exterior chine or the boat will trip and be very unsafe. Well Bolger must have not read Petes book.
This chine protrusion, lip, extension, winggy thing what ever I feel works very well to stop the slipping you would otherwise get with out it. I have learned much since meeting Matt Laden, comparing boats and ideas. Now mine are very short. As in 12' long on HFM. Not too big.
I can see how they work when I pull up my daggerboard or when I raise the centerboards on the other two Hogfish designs.
BUT they do not give lift, not like some wing Keels can. They work best when the boat is hard pressed and heeling over in a breeze. If it's light winds and we are trying to sail to weather in 4' of water the sails cannot be sheeted in too tight. As the breeze increases then you can see and feel the dig. You can see the grip by looking over the stern at the wake.
This is very low tech stuff here.
Lots of people dreaming of a shoal water simple boat would love to not have to build a board into their boat and also give up that space.
A Chine keel- wing like this WILL NOT WORK in anything bigger than maybe 18'.
Why because you will need to use human ballast to lean the boat over to get it to dig in. This is impractical. Windage comes in to play.
It's a good addition for gunk holers as a simple thing to add when building your boat.
Here's showing what I feel is the difference between a traditional vee bottom and the Hogfish types.
See the difference in vee in going to windward in a decent breeze. The vee bottoms bow gets flatter.
Notice the freeboard. Must reef earlier in the upper boat.
That's as far over as the HFM sails in 20-28 knts with one reef in the main.
Showing a box boat. I've never seen a picture of one in strong winds so I'am only speculating here.
If you have some pictures in a strong breeze please send me some.
To finish up here's some thoughts on rudder depths. Some loose drawings of contemporay designs and their rudder depths. I'll go offshore in any of those that go below the hull bottom. The others will be very hard pressed in a breeze as they will have to shorten their sail to handle the speeds and loads.
If you have no offshore sailing plans than no big deal.
Rained all this afternoon today so no more work re installing Wild Birds deck Hardware. Time to write a post while Rachel cooks dinner.
It's Movember , mustache month. Rachel and I having lunch between squalls today.