Information from Wikipedia.

The 1930s

Sir Thomas Lipton challenged the America's Cup for the last time at age 79, in 1929. The Universal Rule's "J" Class was chosen for the boats, with a waterline length between 76 ft (23.16 m) and 88 ft (26.82 m) and a 4,000 lb (1,814 kg) mast. This last particular constrained variations on the sail area, but contributed to adopt the bermuda rig and drop the bowsprit; These improvements had been carried out in small sailboats in the previous decade. The NYYC chose a new venue for the race: Newport, Rhode Island. Four syndicates replied to the challenge, despite the Wall Street Crash of 1929, and built a defender each. The syndicate of Harold Vanderbilt was especially meticulous, studying Newport's weather data for the previous twenty years. To design a truly modern yacht, Vanderbilt chose the Herreshoff's Manufacturing Company's new architect, Starling Burgess, for his experience as a navigator and a hydroplane designer. His yacht Enterprise promptly eliminated his three NYYC opponents in selection trials and was chosen to the defend the America's Cup. Charles Ernest Nicholson designed for Lipton's challenge an anachronistic boat: Shamrock V, the first J-Class ever afloat, was masted and planked in wood. Her poor performance to windward left her behind Enterprise in every race of the Cup.

Improvements from aeronautics first benefited the British with the challenges of aviation pioneer Sir Thomas Sopwith, and Charles Ernest Nicholson's lead engineer Frank Murdoch, previously from aircraft manufacturer H.G. Hawker Engineering. Despite new defeats in the America's Cup in 1934 and 1937, the British challenges forced the Americans onto the path of innovation. Between 1930 and 1937, the improvements brought to the design of sailboats were numerous and significant:

• solid-rod lenticular rigging for shrouds and stays (1930 – 1937)
• normalisation of the bermuda rig and nylon symmetric spinnakers on large sailboats (1930 – 1937)
• multiplication of spreader sets: one set previously (1914), two sets (1930), three sets (1934), four sets (1937)
• multiplication of the number of winches: 23 winches, Enterprise (1930)
• electronic navigational instruments borrowed from aeronautics and repeaters for windvane and anemometer, Whirlwind (1930)
• large boom "Park Avenue" (mainsail foot trim), Enterprise (1930)
• aluminium mast (Duralumin), Enterprise (1930)
• quadrangular jib, Endeavour I (1934)
• flexible stayed boom "North Circular" (mainsail foot trim), Rainbow (1934)
• normalisation of the Genoa Jib on large sailboats, Rainbow (1934)
• riveted Duralumin mast (80,000 rivets), Rainbow (1934)
• the World's largest symmetric spinnaker, Endeavour II (1936)
• Duralumin wing-mast, 77F-Ranger (1937)

All these improvements would not have been possible without the context of the America's Cup. The competition was a bit unfair because the British challengers had to be built in the country of the Challenging Yacht Club (a criterion still in use today), and had to sail on their own hull to the venue of the America's Cup (a criterion no longer in use today): The design for such an undertaking required the challenging boat to be more sea-worthy than the American boats, whose design was purely for speed in closed waters' regattas. The yachts that remain in existence are all British, and probably log more nautical miles today than they ever did. This would not have been possible if Charles Ernest Nicholson did not obtain unlimited budgets to achieve the quality of build for these yachts. Yacht designer Clinton Hoadley Crane noted in his memoires that "America's Cup racing has never led to good sportsmanship. The attitude of the New York Yacht Club [...] has been more that of a man in the forward position at war who has been ordered to hold his position at all costs – at all costs."^[1]. In 1930, Thomas Lipton spent $1,000,000 for his Shamrock V challenge when America was facing a stock market crash, but the NYYC still built four yachts. The rivalry lead both countries to put a display of true technological demonstrators using the maximum load waterline length authorised by the rule for Endeavour II and Ranger in 1937. This seems to concur with J.P. Morgan's famous quote about yachts: "If you have to ask how much it costs, you cannot afford it."

Most J-Class yachts were scrapped prior or during World War II because steel and lead had become precious to the war effort. In the post-war era, J-Class racing was deemed far too expensive, so no challenge for the America's Cup was placed until 1958 with the smaller third International Rule 12mR class. A revival of the J-Class was triggered in the 1980s when Elizabeth Meyer refitted Shamrock V and Endeavour I.

[edit]List of J-Class yachts

10 yachts were built to the J-Class rule between 1930 and 1937, 6 in America and 4 in Great Britain. All three which survived were designed by Charles Ernest Nicholson:Shamrock V, Endeavour I and Velsheda, which never served for an America's Cup challenge.

Other boats raced in J-Class regattas: The yachts Katoura (Starling Burgess, 1927), Resolute (Nathanael Herreshoff, 1914) and Vanitie (William Gardner, 1914) served as trial horses and most International Rule 23mR yachts were converted to the J-Class, of which three remain in existence: Astra, Cambria and Candida.

A replica of Ranger in 2004 accelerated the revival of the J-Class. She is followed by the build of six new yachts, amongst which three replicas (Hanuman, Rainbow andEnterprise) and three original designs by the contemporary architects Starling Burgess & Olin Stephens (77C-Lionheart, 1937), Frank Cabot Paine (A-Atlantis, 1935) and Tore Anton Holm (Svea, 1937).

J-Class conversions       did not compete or qualify       Challengers       Defenders
Launch	Sail	Name	Designer	First ship-owner and Yacht Club	Description
1893	K1	Britannia	George Lennox Watson	Edward VII  RYS	converted to the J-Class (1931). scuttled after King George V's death (1936). replica in construction
1907	K7	White Heather II	William Fife III	Myles Burton Kennedy - Royal Albert YC	23mR converted to the J-Class (1930). scrapped to cast the lead forVelsheda (1932)
1928	JK2	Astra	Charles Ernest Nicholson	Sir Adam Mortimer Singer  RYS	23mR converted to the J-Class (1931). refitted (1987)
1928	K4	Cambria	William Fife III	Sir William Berry  RYS	23mR refitted (1995, 2001). Re-rated as a J-Class (2003)
1929	K8	Candida	Charles Ernest Nicholson	Hermann Anton Andreae  RSYC	23mR converted to the J-Class (1931). refitted (1989)
1930	JK3	Shamrock V	Charles Ernest Nicholson	Sir Thomas Lipton  RUYC	Challenger (AC1930). refitted by Elizabeth Meyer (1989).
1930	J4	Weetamoe	Clinton Hoadley Crane	George Nichols syndicate NYYC	eliminated (AC1930, AC1934). sold for scrap (1937)
1930	JUS2	Yankee	Frank Cabot Paine	John Silsbee Lawrence syndicate  NYYC	eliminated (AC1930, AC1934, AC1937). sold for scrap (1941)
1930	3	Whirlwind	Lewis Francis Herreshoff	Landon Ketchum Thorne syndicate  NYYC	eliminated (AC1930). sold for scrap (1935)
1930	4	Enterprise	Starling Burgess	Harold Vanderbilt syndicate NYYC	winner 4:0 (AC1930). sold for scrap (1935). replica in construction
1933	JK7	Velsheda	Charles Ernest Nicholson	William Lawrence Stephenson RYS	refitted (1997). World's tallest carbon fibre mast (56m, 2008)
1934	JK4	Endeavour I	Charles Ernest Nicholson	Sir Thomas Sopwith  RYS	Challenger (AC1934). refitted by Elizabeth Meyer (1984)
1934	J5	Rainbow	Starling Burgess	Harold Vanderbilt syndicate NYYC	winner 4:2 (AC1934). eliminated (AC1937). sold for scrap (1940). replica in construction
1936	JK6	Endeavour II	Charles Ernest Nicholson	Sir Thomas Sopwith  RYS	Challenger (AC1937). sold for scrap (1947). replica (Hanuman, 2009)
1937	J5	77F-Ranger	Starling Burgess & Olin Stephens	Harold Vanderbilt syndicate NYYC	winner 4:0 (AC1937). sold for scrap (1941). replica (Ranger, 2004)

[edit]Specifications of the J-Class

sailplan of a J-Class yacht

The Universal Rule, and the J-Class, was established in 1903 by Nathanael Herreshoff and the