Oracle pumping claims appear to be fatally flawed.
Claims by an American journalist, Bruce Knecht that Oracle Team USA broke the pumping rules in the 2013 America’s Cup would appear to be fatally flawed. The newly released book ‘The Comeback: How Larry Ellison’s Team won the America’s Cup’ has it that Oracle Team USA used a technique known as ‘pumping’, whereby the crew reeled in the wing to the against the wind and then let it out again. This was done at the start of each tack to get the boat foiling more quickly.
To be effective the sheet must be pulled in rapidly, quickly released, and then sheeted in rapidly.
In the book, Bruce Knecht a former reporter for The Wall Street Journal is also a sailor with a trans Atlantic crossing in his logbook, claims pumping was prohibited under the Racing Rules of Sailing, America’s Cup edition.
While an interesting theory, the story appears to ignore the fact that the normal rules relating to ‘pumping’ or Manual Propulsion (RRS42) were largely removed from the Racing Rules used in the 34th America’s Cup.
RRS42 Propulsion did remain in the America’s Cup version of the Racing Rules of Sailing, but it consisted of just the three lines of the basic rule. The full rule used in the Olympics and other events, covers over three pages and then has a further schedule of interpretations which again run to several pages.
In ‘The Comeback: How Larry Ellison’s Team won the America’s Cup’ Knecht correctly quotes the Racing Rule used in the America’s Cup, but then tacks on the comment ‘The permissible adjustments to the wing do not include the repetitive movements that are required for pumping.’ That last sentence is just not in the rules and does not apply. All Oracle Team USA would claim in a protest is that they were adjusting the trim of the wing – which is what the rule says is permitted. There is no comment or limitation in the rule as to how many times a crew may trim a sheet, and the only conclusion is they can do it as much as they like.
Loads on the mainsheet of the AC72 yachst are not widely quoted, but data from the 33rd America’s Cup from Oracle Team USA indicated that the 120ft trimaran had 26tonnes of mainsheet load with their conventional rig, and that reduced to 3tonnes on the wingsail rig. The output of an America’s Cup grinder is often compared to be similar to that of a domestic sewing machine, and that is only for a short burst before the burn of lactic acid cuts in.
A wingsail mainsheet is quite different from a regular yacht in that it just controls the lateral movement of the wingsail, which it can move in and out. For the pumping to be effective as claimed the entire wingsail would need to be locked to prevent it from just folding around its centre, and Oracle Team USA would also have to be able to reduce the twist in the wingsail to enure that any energy generated by pumping would not be lost in flex of the wingsail. In other words, to be completely effective the pumping must be on a very rigid sail.
In Olympic classes, the practice of pumping is loosely referred to as ‘air rowing’ and is used to fan a yacht around the course by the crew pulling rhythmically on a sheet, usually the mainsheet – and manually propel their boat in light winds.
In all Olympic and other classes, RRS42 is often lifted in moderate to fresh conditions or when surfing is permitted, and in that situation there are no limitations on a crews actions regarding trimming, or the other propulsion practice of body pumping, which us used to achieve a similar effect as the rapid trimming, particularly upwind.
In the America’s Cup the rules were changed to say the ‘crew may adjust the trim of the wing, sails …’ and the exceptions to that practice were removed. Pumping the wingsail against the wind was quite legal if indeed it was physically possible in the conditions that prevailed in San Francisco, and if the action would make much difference to the performance of wingsailed 72ft foiling catamaran.
Further, the racing was under the control of on the water judges and umpires as well as off the water scrutiny. Their position is to normally follow behind the racing yachts, and any rhythmical adjustment of a sheet manifests itself in the twitching of the trailing edge of the sailing – wingsail and otherwise. It is hard to believe that the on the water judges could have missed seeing the claimed illegal action over the course of the tail-end of the regatta when Oracle Team USA became dominant.
The constant work of Oracle Team USA crew on the grinder positions to generate pressure in the hydraulic systems has always been freely acknowledged by the team.
But under the racing rules they were entitled to ‘pump’ the grinder handles all race if they wished, or had the energy to do so.
by Richard Gladwell, Sail-World.com NZL