Jeff Stobbe’s striking and beautiful Victorian-style plank-on-edge yacht

Twinkle 3 plank on edge yacht

  plank on edge racing yacht

Jeff Stobbe has written to report on a plank-on-edge Victorian-style racing yacht he launched last year.

Narrow and deep, plank-on-edge yachts enjoyed a period of popularity among the English in yacht racing during the Victorian era, during a time when the argument was whether the heavily ballasted and deep plank-on-edge model was faster than lighter, shallower and more beamy American types. The eventual conclusion seems to have been that exaggerated forms did not hold the secret of speed, and more moderate designs cam to hold sway in yacht racing.

Readers with an interest in these things may remember that Jeff first told intheboatshed.net about his project in California back in 2007.

Here’s Jeff’s message bringing us up to date:

‘I launched Twinkle last summer using the ramp in the Santa Cruz Harbor, where she now resides in the upper harbor. Twinkle is a modified Dodge designed by John Harvey in 1882 and illustrated in CP Kunhardt’s book Small Yachts their Design and Construction.

Twinkle is a true plank-on-edge English racer and very narrow, deep and heavy. I enlarged her to 18ft LOA, 4ft beam and 42in draft. I had planned on adding about 200 lbs of trim lead after launching to an already cast keel of 1200 lbs. This proved to be a miscalculation on my part by about 600 lbs. Now with a ton of lead she sits on her lines.

‘It is hard to imagine 2000lbs of lead on 15ft LWL and 4ft beam. This is the size of a rowboat I built. Plus she is carrying a small Vetus diesel engine of 200 lbs.

‘I added a bowsprit and rigged her as a gaff sloop with 176 square feet of sail. I was somewhat apprehensive on the first sail because even at the dock she is very tender to 10 degrees due to her extremely narrow beam.

‘She is an open boat on a big ocean and if capsized would go down, well, like a lead fishing sinker. She did stiffen up around 15 degrees but was still too tender. I took 18in off the foot of the mainsail and ended up with about 156 square feet of sail. This is much better and lowered the center of effort a bit also.

‘She is quite quick for her short water line and soon reaches hull speed. Despite her narrow hull and lack of flare she rises to a sea fairly well, and free of green water on the deck. She points well, but not up to modern standards, and has real speed off the wind. I am never going to get used to the alarming angle of heel she assumes in a breeze and perhaps she is just a bit small for the open ocean. I just plan on motoring in if it gets over 15 to 20 knots of wind.

‘This is not inexperience speaking. I have sailed from Mexico to Canada on boats I have built and spent years racing sailboats. This is one very beautiful but scary boat.

‘She demands some prudence but in her comfort zone is amazingly pleasant to sail. Her extreme dimensions means she never misses stays even when slapped by a wave in light air. She motors very well but a little wet at hull speed.

‘It’s very difficult to admit but I consider her a failure. She is crowded with three people, pleasant with two and really can’t be handled well alone when raising sail or, in my special case, of having to lower the mast to clear a bridge in the harbor every outing.

‘I am going to abandon her as a sailboat. It was a pleasant build and she is just a gorgeous hull form that had to be brought to life. I have already started a new project again, an enlarged version of a Joel White Haven 12 1/2 enlarged to again 18ft. The hull is almost done on the new boat and it also is cold molded.

‘I will sail Twinkle this summer and dismantle her in October putting the Vetus and some of the ballast in the new boat. I don’t quite know what to do with Twinkle but right now I am thinking of an electric launch. Cutting almost two feet off the bottom will reduce the volume a bit and still leave plenty of displacement for batteries.

‘Jeff’

Thanks hugely for this Jeff! I’m sure it’s been an interesting journey and the boat’s beautiful – it’s a shame the boat has the usual disadvantages of the plank-on-edge type, even if it is wonderfully elegant. Good luck with the extended 12 1/2 – I’m sure that will be a winner on every front!

PS – Boat designer Mike Storer has written a piece on plank-on-edge sailing craft here.

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Two excellent free boat calculators

Sailcalc in operation

Boating enthusiasts love to fiddle with things – for many of us it’s part of the joy of owning and using boats. Some, like me, go further and start to create actual new boat designs, even if we do keep our creations on the small and simple side of the street.

If you’ve tried designing or re-designing a rig, you’ll know that the arithmetic can be tiresome and if you have you’ll be interested in these two calculators developed by one of my friends from the Yahoogroup Boatdesign, Peter Vanderwaart.

The first is Boatcalc, a handy calculator for use with boat hulls modelled using Gregg Carlson’s very useful Chine Hull Developer. See the Boatcalc_documentation. Even if you’re not working on a boat designed using this software, it may be worth reverse-modelling an existing hull in order to make your calculations, and to study its hydrostatics, wetted area and so on.

The second is Sailcalc, a fabulously useful rig calculator that works out centres of effort, sizes and dimensions – from experience, I can tell you that it’s a boon when you’re trying to balanace up the hull of a boat, its skeg and centreboard, and a mast that can only be in one place and a variety of sail options.