Spirit of Acorn . com
Creating a small keel yacht designed for the soul, not the ego
Skyline of Melbourne, Victoria, Australia from Spirit of Acorn
Design
The construction technique for Spirit of Acorn had already been decided. The hull was to be strip plank western red cedar with epoxy glass skins. This would reduce maintenance to similar to a fibreglass boat, while preserving the warmth of timber inside.
Freeboard was to be increased (I'm 1.8 metres or 6 feet tall) to give a little more internal room, plus more separation from the water. The curved timber transom was essential, but the bow required resolution. The end result has rather an S&S or Dragon look about it, not as blunt as the original.
The cabin was to be extended to allow a front escape hatch in view of the diesel to be fitted (although built to take a diesel saildrive, this has not been fitted).
I decided I wanted the secure feel of the original Acorn, but with more manoeverability. To this end the cut away long keel became a 620 kg lead fin, but with the rudder skeg mounted. This also allowed a 10hp Yanmar Sail Drive to be used, simplifying installation.
Ray Cole decided that with Luke and I in the cockpit, Tumani ("I'm a Nut" backwards in case you haven't worked it out yet) was squatting slightly. While this may be a reflection of me being overweight, because Luke certainly wasn't, we also had to provide enough bouyancy for 100kg of diesel. The hull shape was adjusted to compensate.
We kept the original beam of 6 feet 6 inches because I was not wanting a caravan, but length grew to 20 feet with the changed bow shape. This also allowed for a little more sail area.
So how close is the new design to the old? There are a lot of differences as befits the passing years, but we have the "Spirit"!
Ray Cole , MIE Aust., AMSNAME, MSSCD has kindly provided some comments:
"The original design was characteristic of the hulls decks and rigs of the era, and did have a timeless grace
about her. Discoveries in Materials Science and applications arising from them meant that alloy spars for
fractional rigs such as she carried could be better supported by swept back spreaders. Such a rig, if properly
designed needed neither running backstays nor jumper struts; pesky things, which pose respectively an
unwanted extra task when going about and chafe problems on running rigging such as the spinnaker halyard
when carrying the extra shy.
The major design problem however was a simple one, with a difficult solution. The simplicity was that Paul
simply would not fit in the Acorn; or if he did get below he would have had to come on deck to change his
mind! The difficulty was that like me, he had been well and truly seduced, by the magically written article "
Before You Let Her Go" (found in The Story). Bob Andrews weaved a magic web with his words, and we were
both ensnared. I remembered many years ago looking at some designs of Ted Brewer, Bob Wallstrom
William Garden and Bob Perry who had retained the charm and character of the above water appearance of
a design and successfully married the hull to modern underwater lines which made the boats more efficient
yachts, and wondered if we could do the same with the Acorn.
The difficulty was to do this in a way that would retain the charm of the Acorn and draw a boat which would be usable and comfortable in the waters on which she would be used. The Preliminary Drawings which finally emerged show a higher freeboard; a slightly more raked bow in order to balance the ends, and an extended coachouse to provide more volume below. The higher freeboard should help to keep her drier in the notorious Port Phillip chop, and will delay deck edge immersion if Paul ever presses her too hard. The rig will be simple, with all lines coming aft to the cockpit. Stability, and Power-to-carry Sail. analyses proved very satisfactory. We believe she will sit nicely on the water at rest, and draw many an admiring glance from those who know of how ayacht should look. We believe she will sail to windward like a yacht should, without a football team on the rail.
The Spirit of Acorn should move about among the plumb stemmed, bulb keeled, heavily roached multitudes, prior to the starts; and perhaps a few of those on the windward rails will look at the couple in her cockpit as she slips by, and think that the afternoon is better for having sailed in her company.
If this happens then Bob Andrews will not have weaved his words in vain."
SEE MORE OF RAY'S EXCELLENT DESIGNS AT www.smallcraftdesign.com.au.
The construction technique for Spirit of Acorn had already been decided. The hull was to be strip plank western red cedar with epoxy glass skins. This would reduce maintenance to similar to a fibreglass boat, while preserving the warmth of timber inside.
Freeboard was to be increased (I'm 1.8 metres or 6 feet tall) to give a little more internal room, plus more separation from the water. The curved timber transom was essential, but the bow required resolution. The end result has rather an S&S or Dragon look about it, not as blunt as the original.
The cabin was to be extended to allow a front escape hatch in view of the diesel to be fitted (although built to take a diesel saildrive, this has not been fitted).
I decided I wanted the secure feel of the original Acorn, but with more manoeverability. To this end the cut away long keel became a 620 kg lead fin, but with the rudder skeg mounted. This also allowed a 10hp Yanmar Sail Drive to be used, simplifying installation.
Ray Cole decided that with Luke and I in the cockpit, Tumani ("I'm a Nut" backwards in case you haven't worked it out yet) was squatting slightly. While this may be a reflection of me being overweight, because Luke certainly wasn't, we also had to provide enough bouyancy for 100kg of diesel. The hull shape was adjusted to compensate.
We kept the original beam of 6 feet 6 inches because I was not wanting a caravan, but length grew to 20 feet with the changed bow shape. This also allowed for a little more sail area.
So how close is the new design to the old? There are a lot of differences as befits the passing years, but we have the "Spirit"!
Ray Cole , MIE Aust., AMSNAME, MSSCD has kindly provided some comments:
"The original design was characteristic of the hulls decks and rigs of the era, and did have a timeless grace
about her. Discoveries in Materials Science and applications arising from them meant that alloy spars for
fractional rigs such as she carried could be better supported by swept back spreaders. Such a rig, if properly
designed needed neither running backstays nor jumper struts; pesky things, which pose respectively an
unwanted extra task when going about and chafe problems on running rigging such as the spinnaker halyard
when carrying the extra shy.
The major design problem however was a simple one, with a difficult solution. The simplicity was that Paul
simply would not fit in the Acorn; or if he did get below he would have had to come on deck to change his
mind! The difficulty was that like me, he had been well and truly seduced, by the magically written article "
Before You Let Her Go" (found in The Story). Bob Andrews weaved a magic web with his words, and we were
both ensnared. I remembered many years ago looking at some designs of Ted Brewer, Bob Wallstrom
William Garden and Bob Perry who had retained the charm and character of the above water appearance of
a design and successfully married the hull to modern underwater lines which made the boats more efficient
yachts, and wondered if we could do the same with the Acorn.
The difficulty was to do this in a way that would retain the charm of the Acorn and draw a boat which would be usable and comfortable in the waters on which she would be used. The Preliminary Drawings which finally emerged show a higher freeboard; a slightly more raked bow in order to balance the ends, and an extended coachouse to provide more volume below. The higher freeboard should help to keep her drier in the notorious Port Phillip chop, and will delay deck edge immersion if Paul ever presses her too hard. The rig will be simple, with all lines coming aft to the cockpit. Stability, and Power-to-carry Sail. analyses proved very satisfactory. We believe she will sit nicely on the water at rest, and draw many an admiring glance from those who know of how ayacht should look. We believe she will sail to windward like a yacht should, without a football team on the rail.
The Spirit of Acorn should move about among the plumb stemmed, bulb keeled, heavily roached multitudes, prior to the starts; and perhaps a few of those on the windward rails will look at the couple in her cockpit as she slips by, and think that the afternoon is better for having sailed in her company.
If this happens then Bob Andrews will not have weaved his words in vain."
SEE MORE OF RAY'S EXCELLENT DESIGNS AT www.smallcraftdesign.com.au.
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