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Bump's World - June 2011
June 22, 2011
SPINNAKER EVOLUTION
The sailmakers have 2 objectives in spinnaker evolution. The first is to make the sail easier to handle. The second is to make the sail faster.
Sailors thousands of years ago discovered that you can really pile on the sail area down wind compared to upwind. So they built much bigger sails to balloon out down wind. With the development of new fabrics a much lighter material could help the much bigger sails. This is because the loads are much less on the sail than on an upwind sail.
Originally to stabilize the huge amount of sail poles were used to extend the sail. That evolved into the symmetrical spinnaker which is even popular today. The sail needs to work the same on both tacks so the each side is a mirror image of the other. The pole holds out one side and the other flies free with a sheet for adjustment. Many different materials and designs were used, star shaped, triradial, and paneled etc. Sailmakers argued about design and materials to promote themselves.
The cruising people found all the lines and adjustments of the symmetrical spinnaker very difficult, so for the most part they avoided them. In the mid 1980s the sailmakers introduced the cruising spinnaker. This is a free flying, nylon sail, that flies without a pole and is tacked to the bow. The only adjustment is the sheet. There was some positive response to this sail, however it is still difficult to set and very unstable. The sail tries to fill with wind the minute you start to hoist it. This results in the whole sail falling over board and becoming a huge sea anchor. This also results in the sail almost never being used.
By the late 1980s the sailmakers introduced the launching sock. This enabled to the sail to be hoisted without filling until the sheet is pulled and the sock is pushed to the top of the sail where it stays until the sheet is released and gathers the sail back in. The sock was a big improvement and stimulated more sales of this sail.
With PHRF racing encouraging more boats to get involved in racing, many cruisers tried using their cruising spinnaker. PHRF assigned a 9 second credit to encourage these people to get out racing.
The sailmakers jumped on this idea and began to build racing asymmetrical spinnakers that qualified under PHRF as a cruising style spinnaker. The development of the asymmetrical spinnaker was intense as each sailmaker wanted to take the lead in development. The racing asymmetrical is designed to rotate to the windward side of the boat allowing the boat to sail much deep down wind and often very close sailing angles to the symmetrical spinnaker.
The asymmetrical had to be jibbed by flipping it around to the other side. This proves to be not that challenging.
Now designers and builders make boats designed for the asymmetrical spinnaker. These have poles that extend the spinnaker out in front of the boat. To really pile on the sail area the designer will put a masthead spinnaker on a fractional rig headstay. The poles extend out from the bow and then retract for up wind sailing. The moving pole made for an engineering nightmare and most sort of worked at best. The newest designed boats have fixed bow sprits to get away from that issue. The funny thing is all the old wooded sailing ships had bow sprits.
The cruising asymmetrical is still unstable to fly and difficult to launch. The sailmakers now have introduced roller furling for the spinnaker. Nylon does not like to roller furl much so they recommend a mylar fabric that works much better. They call this sail a gennaker because it can be used at angles much closer to the wind than a nylon sail. Sailors like a stable broad reaching sail instead of a very unstable dead down wind sail, so the gennaker works well. The gennaker is also trimmed more like a genoa than a spinnaker which most sailors are more comfortable with.
So now we have roller furling gennakers which really make life a lot easier. You can hoist the roller furler and sail at the beginning of the day and leave it up. Just unfurl the sail when you want to use it. If you jibe you just furl it and unfurl it on the other jibe. The furling unit and sail set forward of the jib roller furler.
To see where ease of sailing is going look at the single handed around the world racers are doing. Multiple furling sails for different conditions. Do I miss crawling around the fore deck changing one sail after another? I don’t think so, I’m getting old and lazy.
Please mail comments to me at Bump@newwaveyachts.com
Bump Wilcox
Bump's World - June 2011
June 22, 2011
SPINNAKER EVOLUTION
The sailmakers have 2 objectives in spinnaker evolution. The first is to make the sail easier to handle. The second is to make the sail faster.
Sailors thousands of years ago discovered that you can really pile on the sail area down wind compared to upwind. So they built much bigger sails to balloon out down wind. With the development of new fabrics a much lighter material could help the much bigger sails. This is because the loads are much less on the sail than on an upwind sail.
Originally to stabilize the huge amount of sail poles were used to extend the sail. That evolved into the symmetrical spinnaker which is even popular today. The sail needs to work the same on both tacks so the each side is a mirror image of the other. The pole holds out one side and the other flies free with a sheet for adjustment. Many different materials and designs were used, star shaped, triradial, and paneled etc. Sailmakers argued about design and materials to promote themselves.
The cruising people found all the lines and adjustments of the symmetrical spinnaker very difficult, so for the most part they avoided them. In the mid 1980s the sailmakers introduced the cruising spinnaker. This is a free flying, nylon sail, that flies without a pole and is tacked to the bow. The only adjustment is the sheet. There was some positive response to this sail, however it is still difficult to set and very unstable. The sail tries to fill with wind the minute you start to hoist it. This results in the whole sail falling over board and becoming a huge sea anchor. This also results in the sail almost never being used.
By the late 1980s the sailmakers introduced the launching sock. This enabled to the sail to be hoisted without filling until the sheet is pulled and the sock is pushed to the top of the sail where it stays until the sheet is released and gathers the sail back in. The sock was a big improvement and stimulated more sales of this sail.
With PHRF racing encouraging more boats to get involved in racing, many cruisers tried using their cruising spinnaker. PHRF assigned a 9 second credit to encourage these people to get out racing.
The sailmakers jumped on this idea and began to build racing asymmetrical spinnakers that qualified under PHRF as a cruising style spinnaker. The development of the asymmetrical spinnaker was intense as each sailmaker wanted to take the lead in development. The racing asymmetrical is designed to rotate to the windward side of the boat allowing the boat to sail much deep down wind and often very close sailing angles to the symmetrical spinnaker.
The asymmetrical had to be jibbed by flipping it around to the other side. This proves to be not that challenging.
Now designers and builders make boats designed for the asymmetrical spinnaker. These have poles that extend the spinnaker out in front of the boat. To really pile on the sail area the designer will put a masthead spinnaker on a fractional rig headstay. The poles extend out from the bow and then retract for up wind sailing. The moving pole made for an engineering nightmare and most sort of worked at best. The newest designed boats have fixed bow sprits to get away from that issue. The funny thing is all the old wooded sailing ships had bow sprits.
The cruising asymmetrical is still unstable to fly and difficult to launch. The sailmakers now have introduced roller furling for the spinnaker. Nylon does not like to roller furl much so they recommend a mylar fabric that works much better. They call this sail a gennaker because it can be used at angles much closer to the wind than a nylon sail. Sailors like a stable broad reaching sail instead of a very unstable dead down wind sail, so the gennaker works well. The gennaker is also trimmed more like a genoa than a spinnaker which most sailors are more comfortable with.
So now we have roller furling gennakers which really make life a lot easier. You can hoist the roller furler and sail at the beginning of the day and leave it up. Just unfurl the sail when you want to use it. If you jibe you just furl it and unfurl it on the other jibe. The furling unit and sail set forward of the jib roller furler.
To see where ease of sailing is going look at the single handed around the world racers are doing. Multiple furling sails for different conditions. Do I miss crawling around the fore deck changing one sail after another? I don’t think so, I’m getting old and lazy.
Please mail comments to me at Bump@newwaveyachts.com
Bump Wilcox