I don't think that you understood a thing that I said Talk about a guy who won't take yes for an answer. I was mostly agreeing with you...
Quote-Cormeum says,"Thanks for making my point. If the rig is so good that it made up for hull inefficiencies, shouldn't it be looked at again with more efficient hull shapes?"
Seriously, starting from the back and working forward, I did not and would never say that the traditional gaff rig is so good that it made up for hull inefficiencies. Paraphrasing what I actually said, was that the traditional hull forms were so poor, that they were ideally suited to a mediocre rig like the gaff rig. In other words they would not benefit from a higher efficiency rig like a Bermuda rig. In terms of where the historic style gaff rig worked best. it was on hulls that took a lot of force to push, but which could not stand up to their rigs and whose pointing and running ability was limited by their hull and keel configuration so a righ that could not point well or run well was not as much of a liability as it would be on a more efficient hullform.
But I was basically agreeing with you that Marchaj's findings are correct, but also saying that they were nothing new even when he made them some 15 or so years ago. With the exception of the crab claw rig, his research basically quantified what was previously known empirically.
Quote-Cormeum says,"As I said, you really can't compare apples to oranges by mixing hull forms with rig efficiencies. You need to remember that both the newer Rules, which heavily taxed sail area as well as stability and as the burmudan's somewhat better windward ability (no argument there) killed the gaff rig in racing. Not necessarily some "great new thing" with burmudan mains."
You actually have the change in the rule partially wrong, and the chicken and egg backwards. The newer rules reduced the tax on stability with the intent of encouraging safer boats. Because of this plank on edge cutters were replaced with the later compromise cutters and as these boats gained stability they could have more efficient underbodies leading to the need for more effiencient rigs.
While you are right that hull forms evolved dramatically during the period when the gaff rig was dying out, it was a something of a chicken and egg situation. I once had a conversation with Olin Stevens at a Chesapeake Sailing Yacht Symposium. Olin was one of the authors on developing efficiency coefficients for the IMS rule using the schooner Brilliant as a test bed to validate their numbers. Olin was asked why the schooner rig died out and Olin anwered that as lead external ballast was popularized boats became more stablle and did not require as much internal volume to carry the ballast. With that hulls and keels could be made more efficient, meaning less drag for the amount of resistance to leeway and stability generated. At that point rigs needed to get more efficient to keep pace. As cruising boats began adapting more efficient hull forms as well, there was little place where a traditional gaff rig made sense.
But the speed disadvantages of the gaff rig went beyond being hitched to inefficient hulls. Back in the late 1970's I researched Halloween for a white paper that I was asked to write. Halloween had three rigs in her life and each represented a notable period in her then 50 year lifespan. The paper was intended to make a case for which rig she should be restored with. Halloween had originally been built as a Bermuda sloop and was built in total disregard for any rule of that era. After her record breaking race in the Fastnet she was converted to a gaff sloop with the goal of allowing her to race in the 15 meter class. She was later converted to a yawl rig in order to race under the CCA rule under the name of Cotton Blossom.
When she was a Bermuda rig sloop she was in races that included 15 meter class boats with their gaff rigs. The sailing master on Halloween described having an easy time beating them boat for boat on all points of sail and that matches the historical record and mark rounding times. After her first year the Bermuda rig was removed and a gaff rig installed. The gaff rig had substantially larger sail area than the bermuda rig it replaced, yet Halloween could not keep up with on a boat for boat basis with the boats she had previously bested easily. In frustration she was sold several times before being laid up and before being restored and receiving the yawl rig under which she eventually became famous as Cotton Blossom (The predecessor to Dennis Connors' Cotton Blossom). In the VPP analysis done in the early 1980's, she was still clearly faster on all points of sail with the original Bermuda rigged sloop.
But what the metal sails on the Marchaj windtunnel boats showed was that the plan form of a gaff sail has certain efficiencies if twist can be controlled and if the turbulence from the gaff can be eliminated. That cannot be done with a traditional gaff rig. The shape of the mast needs to be round so that the jaws of the gaff will work properly and can be lowered and the spreader positions need to be above the gaff jaws.
But here is where we are in agreement (as I said in my post above). I think we agree that the plan form of a gaff rig has advantages wen reaching if we can address the twist issue and gaff turbulance issue. And I think we agree that there would be an advantage to that more efficient version of a gaff rig. If we can couple that modern gaff rig with a modern hull form, we will end up with a faster boat on the reaching legs. And since modern race boats almost never go dead down downwind, reaching speed is more crucial than ever, and so there would be a real advantage to developing a 'modern gaff rig'.
And in fact that is what has happened. Modern race boats have what they call a "square head mainsail" and which by any other name is in fact modern gaff rig. As stated above, the gaff has been been replaced by a very stiff carbon fiber batten which cantilevers over a swatch of high modulus fiber embedded in the sail. These are wildly expensive, short-lived sails to build, they require running backstays, very high rigging loads, and sharp crews to handle them, but they offer a real speed breakthrough in certain types of racing. Then again, this rig lacks the virtues normally associated with a traditional gaff rig.