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THE FACTS AND FIGURES

LOA 4.5m
LWL 4.43m
BOA 3.35m
Sail Area 14.6sqm Mast 6.8m long 80mm x 55mm
Empty weight 135Kgs
Loaded weight to WL 305Kgs
sheet ply (partly stitch and glue)

The STRIKE 15 trimaran, unlike the Strike 16 and 18, is a complete design and doesn't use parts from other boats (except see below). As on the 16 and 18 the main hull is hard chine. There are two options for the outriggers. Either small, lightweight, rounded V stitch and glue tortured ply, as used on the prototype. Or bigger, more buoyant (thus easier to sail) "soft chine" outriggers. Although it is light enough (just) to cartop (under 130kgs all up), trailering (folded beam is only 2.2m, 7ft3in) is a much more sensible option.

The cockpit is 1.8m x 1.5m (6ft x 5ft) so is large enough to sleep in under a cockpit tent. Thus making the Strike 15 suitable for those who want to race in "raid" style events or even to coastal cruise.

The outriggers fold for transport. This is a common arrangement, first used (I think) by John Westall (the 505 designer) in the early 1970's on the 30ft Ocean Bird trimaran. More recently it has been used on the Dragonfly range of trimarans.

But on all those boats the outriggers fold aft. The Strike 15 folds forward as I think that is a more "fail safe" method. It also means the mainhull is further back on the trailer, so nearer the water and thus easier to launch and retrieve. However, the folding system is complicated to make, so "drop in" crossbeams (similar to those used on the Zeta 14) are also available

The mast is "keel" stepped with a mast gate, while shrouds and conventional spreaders go to the main hull, not the outriggers. That means it can be left up with the outriggers folded when stored ashore in a dinghy park.

For those who want a simple to sail boat with less performance I have also designed a forward mast step which takes a standard unstayed Laser rig.

The Strike 15 is very easy to build with a stitch and glue hard chine hull and flat panel ply decks. Estimated build time ready to paint is 150 hours. I have tried to design it so that each stage can be broken down into 2 hour segments, making it ideal for an evening-after-work project

CLICK HERE for a study plan (in pdf format). A sheet from the building plans is included in the free sample plan pack

Plans cost GBP95 and are available only as download plans in pdf format

The photos below show the prototype Strike 15 being built in Canada.

Photo after 12 hours of work - below

The bulkheads have been cut out and notched. The panels have been butt strapped together and all panel stiffening added. Almost ready to stitch together!

And then a few hours later the daggerboard box/king post assembly is made and glued in position

A bit more fiddling around, making a total of 25 hours work and the hull was ready to assemble. You can see me doing a dry fit below. Note it is all one camera shot, proving it really is an easy boat to put together. And, unlike my other videos, this one does have sound. At this stage the boat weighs 16kgs

https://www.youtube.com/watch?v=J_XRpOCi4BQ

After 100 total build hours the main hull was complete.

Almost finished cockpit. Looking aft (above) forward (below) prior to glassing joints and cutting out daggerboard box

Jetti and Cameron lifting the complete unpainted hull to show its light weight

After a 6 month hiatus when we were out of the country work restarted on the prototype in May 2013. The photo below shows an outrigger ready to deck. Jetti could just lift it with one finger

The cross beams are simple wood trusses. These are strong and light, but more important is that there is a big "hole" at the hull end so water won't slam against the beam. The outer ends are set well above the outrigger deck, again to reduce wave drag.

The outriggers fold forwards for transport, trailering beam is around 2.2m, 7ft. The video below shows how the system works

https://www.youtube.com/watch?v=K-zq-8meTQA

(the boat is at a slight angle, so gravity is opening the boat out, normally it takes a gently push with one finger). The stays attach to the main hull so the outriggers can be folded in with the mast left up for storage in a dinghy park

This photo was taken July 19th and shows the boat nearly finished

and this one, below, on its first sail, Aug 9th 2013, but still unfinished I'm afraid.

Temporary trampolines, no paint on the beams, only primer paint on the hulls - it will eventually be purple, and a 15 year old mainsail. But it sailed just like a performance dinghy, tacking quickly and accelerating fast. Very manoeuverable. So exactly the "geriatric dinghy" concept I was hoping for

After sailing around in light winds for an hour I sailed it back straight onto the trailer (a shame Jetti didn't video it) at 6.05pm. At 6.30 we drove away, slowed considerably by arguing over how best to lash the boat down, it being our first time. Clearly it will get much quicker once we have the trailer sorted. But definitely an easy boat to rig and launch singlehanded

On my second sail we got the time down to 18 minutes, which included me changing into shore clothes. I still need to make a proper bracket to hold the mast on the trailer, and the real trampolines. So 15 minutes is quite feasible. As a comparison, I never managed to rig and launch a Laser dinghy in less than 10 minutes.

The main hull with fittings weighs about 60kgs, the outriggers 12kg each, the crossbeam 2.5kgs each. So all up weight is under the 130kg I predicted

For those who want a less athletically demanding boat bigger hard chine outriggers are now available with more conventional drop in crossbeams. Please email me if you want the hard chine outrigger drawings.

 

and a video here https://www.youtube.com/v/SFymkiKJycU

And the best photo so far taken by Marlene Mackenzie of the BCMS, close reaching at about 8 knots

A report from a French Strike 15 builder (a slightly modified boat)

"Newly launched Strike 15 Citronette had its first testsail on 06 and 07 May. She was very well balanced, light and responsive, a real pleasure to helm. The first day with very light wind she sailed consistently at 7 kt . The second day with more wind, she sailed consistently at 9 to 10 average speed, with maximum 10 s average speed of 11.5 kt (no anemometer record in the close vicinity, but my estimate is around 9 kt average wind).

My feeling to windward was very positive, with average speed comparable to A class cat. On a beam reach I had the feeling of a drag hump to go over 11 kt, compared to my A cat, but it is only a feeling as I had no opponents. The sailing school manager of the club, on the water, reported me he was puzzled by the boat speed with not much wind. Congratulations Richard, Strike 15 is a good vintage!"

and later he wrote "Some news about my Strike 15. Tuning of the boat for solo racing is in progress. I weighted the boat at 280 lbs ready to sail. Best speed to date is 13.5 kt.
Last Sunday during a three rounds regatta with 6 to 7 kts winds I was behind A class cat and Tornado with spinnaker, sometimes very close or before last A cats (despite my very bad starts !), but I consistently beated all the rest of the fleet including Darts (both 1 and 2 up). I achieved same course as A class cat upwind, slightly slower. Faster and closer than Darts upwind, faster and deeper downwind (main and jib only). I wait for comparison with more wind, next year, as it was the last regatta."

Later: "To windward on trapeze two Dart solo were trying to catch me for 8 miles but they couldn't. When returning downwind one succeeded in catching me at the very end. I think I was pointing as we use on A class cat to get speed, but too high for a slower boat ! I was lacking my genny at this time because the wind was dropping"

Still later "Today on my Strike 15 I hit 14.2 kt broad reaching under main and jib, 13.5 kt for 10 s, 12.5 kt over 500 m and 12.1 over a nautical mile. Mean wind was around 14 kt, my lee outrigger near submarined sometimes under gusts, not slowing the boat. The boat looks very sound."

And from the USA, these photos of a Strike 15 (in red) next to a Strike 16

 

Strike 15 Approximate Materials List

6mm gaboon (okoume) marine ply (8ft x 4ft sheets) 1sheet
4mm gaboon (okoume) marine ply (8ft x 4ft sheets) 5 sheets
3mm gaboon (okoume) ply (8ft x 4ft sheets) 3 sheets or 4mm if hard chine outriggers used

2in x 1in 30m
11/2in x 1in 10m
1in x 1in 30m
4in x 1in 10m
3in x 1in 5m

Epoxy resin 10kgs min 200g glass cloth 2kg min
Screws 3/4in #6 counter sunk stainless steel 1000
Filler etc as required
Scrap timber for frame

No allowance for waste. Timber sizes nominal planed all round (PAR) use softwood, eg Douglas fir, Sitka spruce etc

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