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Home , Australia II, Cambria (yacht), Columbia (1871 yacht), Columbia (1899 yacht), Columbia (1958 yacht), Courageous (yacht)

Course of Cup design

Roger Marshall assesses how the rating rules have shaped the Cup over 100 years

r'ntil 1983, the 's Cup was changed, in today's Intemational Offshore Rule. . All the time yachts were getting a symbol of American supremacy. longer. , designed by , Although it has always been an was 2ft Sin short of the 90ft they could be on 2 B event which builds up to fever the waterline whilst Columbia was 2in less than III pitch then fades into obscurity, its L was measured on the LWL. This rule led to this maximum length. Shamrock led in many successful technological developments have the first noticeable burst in development. of the light air races but in heavier winds Col­ e\'entually filtered down to the general The first match under this rule was in 1885 umbia crossed the line first and won the series. fleet to become an everyday part of production between , of shallow and beamy design, Constitution and Independence, specially built designs. and , deep and narrow, in line with for the 1901 challenge, lost in the trials to Col­ In 1870 competed against 23 other British design practice. The launching of umbia but not before Independence's scow- schooners and was defeated by . James Gloriana in 1891 moved design in the shaped hull and lightweight construction had Ashbury. Cambria's owner, challenged again in direction of the metre boat style. A new shown surprising bursts of speed. Her con­ 1871 with . This time the Americans lin­ Nathaniel Green Herreshoff design, she had a struction was so light that she leaked and the ed up four vessels ready to race him and the fin keel, 4,00011^ of , was 46ft on the hull twisted as she sailed. The match was yet match was won by Columbia and then by Sap- waterline but 70ft overall. She won eight races another victory for New York YC but led to plio when Columbia was disabled. Ashbury pro­ in eight starts and Herreshoff, to defend the another challenge from the sporting Sir Thomas tested, with the result that any subsequent Cup, designed and built no less than six Lipton. Sliamrock II, designed by G.L. Wat­ challenger only met one deferider, the racing defenders from 1893 to 1920. He drew son, while extremely fast, was defeated due to format we know today. Gloriana's successor, the centreboarder lack of preparation and experience. She was The rating rules have always played a very . Vigilant was criticised during trials, one of the first boats to be tank tested. interesting part in influencing design. The for the new ideas she encompassed. She fac­ was the biggest boat ever built for schooners of the early races gave way to sloops ed Lord Dunraven's G.L. Watson-designed the America's Cup. At 89ft 8in on the waterline, with the inception of the Cubical Contents rule Valliyrie II in the 1893 match and won three 143ft 8in overall with a sail area of 16,160ft^ in 1880. This rule calculated the volume under straight races. Lord Dunraven challenged again and a mast of about 190ft, defeated Shamrock the sheerline and led to shallow-draught, beamy with another Watson yacht, Valiiyrie III, a boat III, another Fife design, and ushered in a new boats with a huge spread of canvas. Under this close in design to the American . Both era. She was a true extreme yacht: thinly rule the Canadian boat Atalanta was easily boats sported long overhangs, long plated, with a towering rig and long overhangs defeated by Misciiiefm 1887 When one of the and deep keels. The match ended acrimonious­ designed to cheat the 90ft LWL limit. Just five boats taking advantage of this rule sank at her ly when Valkyrie fouled Defender. knots of wind would heel her enough for mooring, drowning all on board, the rule was 1899 saw Sir Thomas Lipton's first challenge Reliance's sailing waterline to increase from 90ft changed. Dixon Kemp proposed what eventual­ in a boat that pushed the limits of the rule. to 130ft due to her 54ft of overhangs. Thus the ly became the Seawanhaka Rule, taking into ac­ Shamrock was 129ft overall with the unlikely came into being: count length and sail area. Its final form has combination of manganese bronze plating under Rating = L x SA survived to be incorporated, though slightly the water and aluminium topsides. She raced 5 Disp , doyen of tiie designers. Right, in 1967 This is the forerunner of today's rule. Lip- ton challenged again in 75ft wateriine boats. Shamrock IV was the first America's Cup boat designed by Charles Nicholson of Camper & Nicholson fame. She was in the mid-Atlantic when Worid War I was declared and eventually lost to yet another Herreshoff yacht, , when the races were finally held in 1920. It was in 1924 that the American and British discussed rules and scantlings and the Thames measurement rule gave way to a 'scientific rule' developed by R.E. Froude which eventually became thé International Rule we have today. By 1928 the American Universal Rule had been adopted for boats over a 76ft waterline or J Class boats, while the British International Rule was adopted for boats under this length.

CONTINUED OVERLEAF

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The J Class saw major design changes: the Bermuda rig replaced gaff-headed mainsails, alloy masts replaced wooden spars and winches proliferated and moved below deck. The boats had now become stripped-out rac­ ing machines and, with new sail developments, were much faster than earlier yachts. Parachute spinnakers, double and triple headsails and Quadrilateral (i.e. double-clewed) jibs came into use. Improvement in headsails and hull design made the 1937 II one of the big­ gest J boats yet built. Olin Stephens and Starl­ ing Burgess worked together and, with a large amount of tank testing, produced which ran away with the series and advanced the shape and a very stripped interior. Once again series was marred by some rating interpreta­ cause of scientific tank testing along the road the defender beat the challenger, the Boyd- tions and decisions which annoyed the Austral­ to acceptability. designed from Britain. ians. When Chance re-designed he With the advent of Worid War II, it was not The biggest advance in design came with Olin moved the rudder stock aft six inches and fil­ until 1958 that the Cup was challenged for again Stephens' masterful Intrepid. Her rudder, with led the space with fairing strips. Thus for and this time it was in 12-metres: boats approx­ a trim tab at the trailing edge to reduce leeway displacement purposes the boat still had a imately 65ft long, weighing 55 to 60,0001b; less and develop more lift, was removed from the waterline length of 45.5ft but an actual waterline than one-sixth of the weight of a J boat and trailing edge of the keel and placed at the end of nearer 46ft. Alan Payne's II had a real diminutive compared with the likes of Shamrock of the waterline. The rudder was prefaced by wateriine of almost 46ft making her 1,8001b III and Reliajice. a large bustle — called a kicker — which had heavier. The Americans held trials with four boats and the effect of moving the quarter wave further Major changes were set for the 1974 it was the S&S designed Columbia which went aft and rnaking the boat appear longer in the challenge. Built in alloy and on to defeat David Boyd's , a British boat water. Wetted surface was also reduced by had a significant weight advan­ criticised for her rounded bows and exaggerated almost seven per cent making the boat poten­ tage over earlier boats in that the hull struc­ pitching. A feature of this challenge was the tially faster in light winds. In her first series ture of wooden boats weighed about 15,0001b; new Dacron and the open cockpit of Scep­ in 1967 Intrepid beat Warwick Hood's Dame the remainder of the weight was in the lead tre which was copied by later Twelves until Pattie 4:0. Dame Pattie weighed approximate­ keel. An alloy boat, on the other hand, had a Courageous almost sank. ly 61,5001b while Intrepid weighed about 56, hull structure at that time of about 10,0001b and the remaining weight in ballast. This had the Four years later in 1962 the AustraEans came 5001b. The lighter boat had better acceleration effect of making the alloy boat stiffer. Mariner, to Newport with Alan Payne's Gretel, a faster in most conditions. another defence candidate, took the In- yacht than the defender Weatlmiy designed by The 1970 series saw a Britton Chance re­ trepidAMant thinking to its logical conclusion. Philip Rhodes. However, lack of experience design of Intrepid beating Gretel II while Olin prevented them winning. Stephens produced Valiant, the logical next The problem with Mariner was that the The next step in the evolution of the step down the path found by Intrepid. Valiant, model in the towing tank allowed the water to 12-metre came with Constellation in 1964. however, had too big a bustle and was too large be fooled into filling the space behind the chop­ Another S&S creation, she had a bendy , altogether. Olin learned from this and produc­ ped off stem making it seem as if the boat were a mast light enough to bend to suit the sail ed the superb Courageous for 1974. The 1970 actually larger than it really was. However, when the tmncation was scaled up to full size, Shamrock II (left) and Columbia after tlie start of the first race in 1967 it became impossible for the \vater to accelerate to such a speed that it could rush into the void and make the full size boat seem larger and hence faster Unfortunately, when Valiant was changed to the same configuration, any refer­ ence point was lost until she sailed against Courageous in the NYYC regatta in Long Island Sound. After a disappointing summer Mariner was sent back to Derecktor yard where she was rebuilt, arriving back in Newport in time to be eliminated in the July trials. That left the way free for a tremendous battle between Courageous and Intrepid. Courageous was even­ tually selected when she won the last race of the series by 41 seconds. She defeated 's first Twelve, Southern Cross, by wide margins in the races for the Cup. Soidhern Cross was a much bigger boat weighing about 61,0001b against Courageous' 56,0001b. Courageous' weight came in for acrimonious debate after the series when it was found that

46 Shamrock IV, 1920 , 1930

she had actually been lighter than the rule Designers have known that a smaller, lighter 45ft. Courageous, , , allowed. Apparently the boat was about 1,1001b boat will accelerate faster than a larger boat, Defender and Libetiy were all close to this size. lighter than declared. But the total weight cut for many years. In America's Cup racing where II, on the other hand was about a foot out of the keel was more than that due to the the boats move close to the same speed this shorter on LWL and on the dimension L. As ruling that cockpits must now be completely is a distinct advantage. The Deed of Gift for L is part of the rating formula and D and F re­ watertight. This and the lighter weight meant America's Cup boats sets a minimum length at mained close to conventional values, the that Courageous' waterline had to be shorten­ 44ft on the wateriine. The LWL also governs designer was able to increase sail area, mak­ ed to make the displacement required by the the minimum weight at about 51,0001b. ing the boat faster in lighter winds. Also reduc­ rule. A total of a few inches was removed from However, until Australia II there was no possi­ ing L reduced the wetted surface by a few per the bow and the boat was ready to compete ble way to get enough stability in a 44ft cent improving light air performance even more. again in 1977. waterline hull for sailing in the heavier winds. In my opinion it was only because of the ex­ In 1977 htdependence, Enterprise and the The practical lowest length evolved at about perience of Conner and his crew that the Cup revamped Courageous were pitted against series wasn't a walk over for Australia II like France I, Gretel II, and Sverige. On the design Intrepid, 1967 the challenger trials had been. • front the Americans were running scared after the towing tank got the blame for the Mariner debacle. Independence was a largely intuitive design from Ted Hood, sailed by him and at­ tempting to use only Hood sails. The S&S designed Enterprise, always said to be a slow boat was, in fact, an almost exactly half way step between Courageous and the boat to come in 1980, Freedom. The only boat which had anything different in design was Pelle Petter- son's Sverige which had pedal-driven winches. Almost by default on the part of the designers the 1977 series had developed into a battle of the sailmakers: Hood versus North, Kevlar and Mylar versus Dacron and nylon. Sail technology moved forward. Finally it was Ted Turner driv­ ing Courageous who beat the Lexcen and Valentijn-designed Australia 4:0. is widely credited with turn­ ing the America's Cup into a full time profes­ sion and for the 1980 series he used Enterprise and the new Freedom. Ranged against him were Clipper, built out of the remains of In­ dependence, and the old warhorse Courageous. AÜ of these designs were close to 45ft on the water and weighed around 56,0001b. At this time, none of the defenders had been tank test­ ed and it was rapidly becoming apparent that the zenith of hull design had been reached. Australia was soundly beaten by Freedom driven by Conner. The consensus in 1980 was that the future Cups would be decided by the sailmakers. That all changed when Lexcen's Australia II appeared on the scene. Her radical keel marked a departure which enabled other things to be done with the design. The wings became a ma­ jor controversial issue as soon as the boat started winning.

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