The Hull Shell, Sheer to Keel, is complete. 1300 hours for 1100kg of planking plus bulkheads (not yet bonded). Almost 1kg per hour to this stage although there is still a few hours of dressing to go.
Dressing involves removing a minimum thickness of the proud plank edges using a small block plane with 25 degree blade bevel .
After dressing the planking is given a light 40G orbital sanding. The new 700W Makita Sander comes standard with a built in Samurai Warrior who endeavours to throw one off the boat particularly when working high up near the keel and hanging on by ones teeth.
Before laminating the 120kg of epoxy E-glass Outer Skin there are a few tasks yet to complete. And then I will need a few days with ambient temperatures less than 30 degrees C. I’m already seeing 42 C at one meter off the floor and 46C higher up nearer the roof, so it may be March 2018 before the outer skin laminates go on. There is plenty of fill in work to keep me busy until then including the Rudder and False Keel.
If I’m not going to get this boat finished for the 2018 GGR then the 2022 GRR seems possible, even with my very slow progress. There will be much to learn from the observing the 2018 race, what works and what does not.
Current Progress includes the Stern Knee installed, tapered stealers filling the gap towards the keel and a few garboard planks still missing as I’ve used up my entire stock.
With most planks on the hull is now taking shape.
Up and down the hull sides so many times its now second habit.
Ducking for head room.
Or stretching. The last few planks are taking a bit longer just because access is a bit more difficult.
Back to building in November…
- 2.5 months since planking started mid May 2017
- 1.164 km of planking, fetched and carried, brads removed, sanded, cut to 36mm width and straightened, scarf joined, fitted up and edge glued and nailed
- 4.08 minutes per linear meter to recover scrap strip planks = 80 hours
- 2.08 minutes per linear meter to cut and glue scarf joins = 54 hours
- 60 minutes to fit up and edge glue one plank = 110 hours
- 150 grams of epoxy resin ( excluding fillers) to edge glue one plank = 16.5 kilograms of epoxy resin
- 244 hours to date for planking
Still to go
- 30 planks to go = 300 linear meters = 30.8 hours for recovery and scarfing + 30 hours to fit up and edge glue = 61 hours
Its time to plan to end planking. The keelson trailing edge is dressed to provide the correct angle relative to planking by extending the power plane’s base with a batten to give a rough finish angle. A follow up with a shooting hand plane will get the angle exact relative to planking. Its also time to add a harness, and maybe a hardhat, to the shopping list.
And now also to improve scaffolding as there will be yet plenty of work to come at height. Thanks to Colin H at least I have the basics. AND now you know what the ropes are for!
Abhilash Tomy will launch his Suhaili Eric Replica built at the Aquarius Boatyard in Goa India, tomorrow 7 August 2017. Looking good…
Don McIntyre the founder and organiser of the Golden Globe Race 2018 has made a pre release announcement in the The Coastal Passage magazine (free emag worth subscribing to..) of his steel Joshua One Design (as sailed by Bernard Moitessier in 1968 Golden Globe Race). At 15 ton she is twice the size of the Eric (8700 kg). More information in TCP #85, pages 13 and 14. In theory the Joshua will be 21 days faster that the Eric for the GGR see Still Planking Blog based on average speed to length ratio for heavy displacement boat speed. For owner builder GGR entrants a Eric CSP one design offers an alternative solution. More to follow…
The end of planking is almost in sight, but formwork is now required. And a friend has offered me his scaffold planks and trestles. Amazingly how help just keeps coming at the right moment.
During the mindless recovery of cedar planks it occurred to me that this boat will be doing a lot of shovelling. Lightship (empty) displacement is about 8 tonnes. The boat length is 10 metres. Every time the boat moves one boat length of 10 meters, 8 tonnes of water is moved aside. If the boat is sailing at say 5.4 knots or 10km per hour. it is moving 10km/10m = 1000 boat lengths per hour. AND that is 1000 x 8 = 8000 tonnes of water pushed aside every hour. Or 192000 tonnes per day. For a 300 day GGR that is a staggering 57600000 tonnes!
On the 21st June at noon local time the sun, directly overhead it seems had no problem tracing an imaginary path around the world at 23.5N latitude as the Earth rotated creating the Tropic of Cancer on Winter Solstice (for us down under). Image – NOAA
My planks are not so easily directed and prefer meridians following a great circle path. Consider a plank running along a lines of latitude on each edge. The sphere’s radius is smaller on the pole side but the planks edges are the same length so it is deflected towards the equator.
The rugby ball approximates the Eric’s hull shape, the first green tape almost follows meridian and starts to kick up (downwards on the ball) at the ends. The orange and subsequent yellow tapes are displaced significantly down towards the ends.
As my planking progresses in parallel runs similar to lines of latitude it starts to get very unhappy as tension and compression forces built up in the opposite edges. This compounded by wind tension as the planks are twisted. Running a wider batten flat against the hull surface establishes a happy curve for the planking to follow.
Cutting off bits of boat is not so happy.
The unhappy planks are soon replaced and with happy planks, much easier.
Despite happy planks progress is so slow, a tack to change course may be needed, but not just yet. The GGR 2022 has been announced by Don McIntyre in the TCP magazine a free e_magazine which is worth a read.
For the GGR 2018 my goal is to improve on Suhaili’s time in 1968 of 313 days according to wssrc. Based on a distance of 30000NM the average speed was 4 knots. .
Displacement yachts seldom exceed a speed to length ratio of 1.3 , with 1.5 just possible. The typical average Speed to Length ratios is 0.9.
Marcaj.C.A – Aero-Hydrodynamics of Sailing
Achieving an average Speed to Length of 0.9 would result in a RTW time of 265 days for an Eric design or 221 day for a Joshua Design.
Nine of the eighty or so planks are now laid and edge glued. The boat is taking shape, a very exciting time. One of the planks cracked and broke between bulkhead 10 and 11 today, hence all the clamps. First thing tomorrow a further three planks each side will be fastened. Each plank is 10.4 meters so a total of 12 per side x 2 sides x 11.4 = 260 linear metres of planking, done. Each plank is 36mm wide, and allowing for 100mm offcut each end gives almost 9 square meters of approximate total of 40, done.
There are a few more lights in the shed and with tarps for walls its getting quite cosy.
Standing on my head and looking forward one gets an idea of the sweeping sheer.
First nine planks with edges planed off. Very soon I can remove the jig extensions to get better access as the hull ends are almost self supporting.
If you think this is a lot of work try this planking a longboat. Have a look at the bow shape when the boat is launched, remarkably similar to the Eric’s bow.
One more photo, I love these lines.
First three planks glued in position, at last.
I extended the jig to get a strong secure mounting for stem and stern post.
Temporary battens at 1/3 and 2/3 midsection girth to check planking run. The batten nearest to the keelson kicks up at fore and aft. The runs seem easy with my 36 x 19 mm strip planks. The original design calls for planks 120 x 32mm which would have been a challenge!
Final shaping of the keelson
Then drill the ballast keel bolt holes.
Then clean up bulkheads and prepare for planking.
A trial dry fit of planking.
Then final checks to ensure bulkheads are straight.
And after a number of trials planking is fitted to starboard side using finger clamps and stainless steel brads.