Reverse Clinker Construction

[charlie.hussey]

Reverse clinker (lapstrake) construction is the practice of starting clinker planking at the sheer strake and planking down to the keel.

Can anyone enlighten me as to why anyone would want to employ this method of construction for a yacht?

You can see an example (designed by McGruers in 1967) at http://search.boatshop24.co.uk/morepictures.asp?btsrefno=8527736

[Ian McColgin]

Dang, learn something every day.

Suppose it keep the leeway down? And the extent to which the laps hold water on the weather side might help keep the boat upright.

HehHehHeh

[rbgarr]

Why not?

[Paul Pless]

that's just not right;)

I've never seen it on a sailboat from the sheer down, but you do find reverse laps on some powerboat bottoms.

[gert]

Is this like starting your roof shingles at the peak?

[JimConlin]

It was done in the bottoms of McKenzie bass boats.

[rbgarr]

Actually it would make fitting the laps easier during upright construction. You'd be looking down on the fit rather than up underneath. On a small boat it may make for less damage to the laps when putting on a trailer also.

[reddog]

John Leather has a couple of paragraphs on reverse clinker planking on pages 102-103 of his Clinker Boatbuilding book.;)

Earl

[HS]

It would certainly make scrubbing down and anti-fouling a lot less irksome, especially on a hard bilged boat...you wouldn't need a mirror-on-a-stick to check for "holidays".

Hans

[boylesboats]

Makes it easier to get back on-board in case you fell over-board...

[charlie.hussey]

John Leather has a couple of paragraphs on reverse clinker planking on pages 102-103 of his Clinker Boatbuilding book.;)

Earl

Thanks - John Leather's explanation is good enough for me.

For those who don't have a copy of Leather to hand the reputed advantages of reverse clinker are:

- easier planking (less twist, planks lie flatter on the boat's sections)
- additional resistance to leeward as the reverse lands act as mini lee-boards
- the boat is easier to clean (inside)

Leather reports claims that such (small) boats can sometimes sail to windward with the centreboard raised.

[Andreas Jordahl Rhude]

Carver Boat Corp. of Pulaski, WI did it on the bottom and chine of their wood lapstrake power boats for a few years in the early 1960s. New company owners ceased that scheme when they took over in 1963.

Andreas

[Jay Greer]

Aside from the fact that the reverse clinker boat looks funny, it has now been proven that a clinker built hull is faster than an identical one that is carvel planked.
In this case it has to do with glass hulled Folk Boats being pitted against the traditionally built boats. Seems that air is trapped under the laps and breaks up the parasitic drag. Also, the laps create lift and better stream flow.
Jay

[Lazy Jack]

Boats built with reverse clinker construction are less likely to be stolen.

[eastfork]

If my memory serves, Lyman boat works in Port Clinton,OH made a few reverse lapstrake 13ft outboard racing boats in the 30's. The idea was, I believe, was that they would handle better in the turns.

[Texasgaloot]

Must be superior stability. Resistance to rolling -- who needs flopper-stoppers?

[Domesticated_Mr. Know It All]

If my memory serves, Lyman boat works in Port Clinton,OH made a few reverse lapstrake 13ft outboard racing boats in the 30's. The idea was, I believe, was that they would handle better in the turns.



Your memory is good but Lyman Boatworks was in "Sandusky",Ohio.

Some info and photos on the 13ft. reverse lapstrake boat here.....


http://www.clinkerbuilt.com/13_racer.html

[tonydezoc]

Tell you what, it would make replacing the garboards a whole lot easier

[Geoffrey Harris]

Peter Spectre had a picture in his On the Waterfront column of a reverse clinker model of a bow, with a statue of a monk standing on it, in a medieval cloister somewhere. I think it was Cluny. He wanted to know whether this was actually practiced or if it was an artist's mistake. Never did get an answer that I recall.

[Doug Hamilton]

In regard to reverse clinker construction, John Leather, on p 102, of "Clinker Boatbuilding" stated that, "---all planks, except for the first two from the keel, are laid from the transom to the sheer---". This statement leaves me wondering what he meant. Does anyone else see an error here?

It seems to me he should have said that the planks, except for the first two from the keel, are laid from the transom to the stem. Even at that I am left to assume that customarily on a clinker-built hull both the garboard and the next plank do not extend forward enough to meet the stem but only enough to meet the gripe. Is it reasonable to make that assumption?

[ahp]

John Gardiner told us in class at Mystic many years ago that the Chinese did it that way, but he didn't tell why.

[Lowroad]

McKenzie bass boat below the chine were plancked that way. It was supposed to be quiet.

[BarnacleGrim]

One advantage I can see to reverse clinker planking is that there will be no standing water between planks on the inside of the hull.

[Yeadon]

Can't get the first link to work. Am I the only one?

[Paul Fitzgerald]

Aside from the fact that the reverse clinker boat looks funny, it has now been proven that a clinker built hull is faster than an identical one that is carvel planked.
In this case it has to do with glass hulled Folk Boats being pitted against the traditionally built boats. Seems that air is trapped under the laps and breaks up the parasitic drag. Also, the laps create lift and better stream flow.
Jay

Jay, can you recall any references to this? I would appreciate them if they exist.

[ahp]

I thought the FG Folkboats had the (fake) laps molded into the hull. There are FG Folkboat derivatives that have smooth hulls, but are they legal Folkboats?

[Paul Fitzgerald]

I thought the FG Folkboats had the (fake) laps molded into the hull. There are FG Folkboat derivatives that have smooth hulls, but are they legal Folkboats?

The smooth ones are called International Folkboats, the lapstrake ones are Nordic Folkboats.
Often race together in club fleets, but distinct racing classes at national and intertnational levels.
I think the glass Nordics still have to use wooden masts as well.

[Spokaloo]

Oh, and Trumpet by Westy Farmer was lapped as you are describing from keel to chine, and lapped normally from chine to sheer.

E

[eric17]

Reverse clinker is the way middle-age "Hulc" (kind of larger Kog...) was build.
Don't ask me why :-)

[Peerie Maa]

In regard to reverse clinker construction, John Leather, on p 102, of "Clinker Boatbuilding" stated that, "---all planks, except for the first two from the keel, are laid from the transom to the sheer---". This statement leaves me wondering what he meant. Does anyone else see an error here?

It seems to me he should have said that the planks, except for the first two from the keel, are laid from the transom to the stem. Even at that I am left to assume that customarily on a clinker-built hull both the garboard and the next plank do not extend forward enough to meet the stem but only enough to meet the gripe. Is it reasonable to make that assumption?

I believe that he is discussing transom sterned dingys, where he is running the streaks diagonally, so that the forward hood end on most planks run out at the sheer. This will allow for the use of narrower stock, with less edge set or belly on the finished streaks.

[holzbt]

McKenzie bass boats had reverse laps on the bottom. It was supposed to help them slide off the rocks better. I've been told that the best fishing is right in the rocks and the boats often bumped them.

[Scot L T]

I was doing some reading on South Asian boat building and apparently reverse clinker construction is quite common in some parts of South East India, Bay of Bengal and neighbouring parts of Asia.

According to the writer it has some kind of religous/philosophical signifigence. He didn't go into it at all but it seems that with reverse lap/clinker God is on your side....can't argue with that!

[Jay Greer]

Jay, can you recall any references to this? I would appreciate them if they exist.
That information was imparted to me, many years ago, by my friend Lyle Hess during a discussion of the virtues of the lapstrake glass hull of his North Sea 27 design.
Jay

[peter radclyffe]

Boats built with reverse clinker construction are less likely to be stolen.
this is a gem http://www.woodenboat.com/forum/images/icons/icon7.gif

[Big Wave Dave]

Lyman boat works used the reverse lapstrake construction from the chine or turn in the bilge to the keel. Bill Lyman believed reversing the laps from the chine to keel would stiffen the hull and thus make it a better racer. He was right, several stock Lyman racers went on to be very successful.