S-rule of 1917
At Anker & Jensen's yard at Vollen outside Oslo they were eager to keep up design work and construction of new yachts. As the R rule of 1907 expired on 31st. December 1917 it was important for the yards to have a common basis for new yacht designs to come. Norway was at the time one of the largest yacht constructing countries in the world, with Anker & Jensen Boatyard outside Oslo in the lead.
Seilas Yachting Magazine reports in August 1917 that Johan Anker, chairman of SSF, was going to suggest to elimate, 1/3B +1/3G, from the formula. The overall division factor to be reduced from 2.2 to 1.95 giving the same division in classes as before. The formula if endorsed would be:
L + 3d + 2/3sqrtS –F
The matter was discussed on meetings in SSF on Saturday and Sunday, September 15th-16th 1917. The purpose was as before to call upon more cruiser friendly and seaworthy designs within reasonable cost.
Discussions were constructive. The meeting agreed to take beam B out of the formula inviting the designers to construct more wide yachts.
The measurement of G was slightly changed compared to the R-rule of 1907. G to be measured in the position were G is largest. If this position is aft mid ship (55%), the sum of girth from covering board to covering board and beam should in no position further aft be more than at the measurement position. This is subject to a straight keel with now hollows.
The major change was the measurement of “d” in line with “X” in Ankers proposal of Feb. 1916. A chain of length 3/8G is stretched from waterline level in G position down to a point on the underwater hull on both sides. The difference between the added skin girths from these two points to the waterline level, and 2 times 3/8G, is “d”.
Penalty on sail area was increased from 1/3 to 2/3 and overall division factor increased from 2.0 to 2.1 compared with the R-1907 rule, keeping the same yacht classes as before. Length L is measured on a level 1% of the rating class above L.W.L. plus girth differences in both ends reflecting the more efficient waterline length.
The outcome was the S-rule of 1917 made in force from Jan 1st 1918, same time as the R-1907 rule elapsed, and made valid for 5 years to follow.
L + 1/3G + 3d + 2/3sqrtS – F
The principles of measuring "L" higher than L.W.L. and limit the measurement of girth difference "d" to a determined point on the skin were later adopted by IYRU in the revised new R-rule of 1919 to come.
Restrictions were put on outfitting and inventory for the different classes. Classes agreed upon were S19, S15, S12, S10, S8, S7 and S6. The 9 meter and 5 meter classes are left out. Cabin top is not a requirement on the 8mS Class and above. The 7mS Class is divided in closed yachts with a limited cabin top of 15cm height and open yachts. The 6mS Class is open yachts. Minimum displacement for the 6m Class is 1.2 tons and for the 7m Class 1.8 tons.
Restrictions on spares were laid down. Hollow masts were not permitted for yachts above 7m. Minimum diameter of masts was laid down. For an Eight, minimum diameter in a position 2/3 of the mast height was 160 mm. No restrictions on weight and length of masts. The thoughts were that this would regulate itself as part of the design.
The S-rule of 1917 was a success. In total 20 Eight Metres were during 1918 and 1919 constructed in Scandinavia based on this formula. The objectives were met. More cruiser friendly yachts with the same hull size as the R (1907) Eights. Increased beam, and the V-shape typical for the latest R (1907) yachts was no more. Sail area was decreased and the yachts were fitted out with Marconi rig and Bermuda sails lot easier to handle for the crew.
Sail racing numbers were organized by SSF. The R (1907) Eights had been given Class identification letter H. SSF decided that the S (1917) yachts should be identified with a letter s (half sized) in addition to the classification letter, i.e. sH for an Eight Metre. Twenty R (1907) Eights had been given racing sail numbers and the first S-Eight listed was sH20 “Borgila” GKSS, designed by Liljegren, Sweden. She was later transfered to Haraldsen in Norway named Sif With sail no. sH 32. Sail no H20 was given to First R-Class 8mR "Sarina" 1912 Burnham, G.N.Laws.. As such sH21 "Bobo II" designed by H.J.Svenningsen, Norway is the first Scandinavian S sail no. remained listed in the Eight Metre Class
For racing between R (1907) yachts and S (1917) yachts SSF had decided upon a handicap of 12 sec. per nautical mile in wind forces less than 5 m/sec due to the R (1907) yachts larger sail area. This was nullified by SSF in their meeting in Copenhagen on September 26th 1919.
The Kattegat Cup was moved to the new 8mS Class and races commenced in 1918 and 1919. Winner both years was sH25 “Apache” designed by Johan Anker.
Kattegat Cup races 2nd day;
sH23 "Ariadne" Denmark" and sH25 "Apache" Norway
In their meeting in Gothenburg on January 18th 1920, SSF decided to move the Kattegat Cup to the new International 8mR Class. No races for the Kattegat Cup was called for in 1920.
In the Antwerpen 1920 Olympics sH27 “La France” commissioned to the R-rule of 1919 with sail no 8N6 and named “Lyn” won silver medal in the 8mR “new class”. Winner was 8N2 "Sildra" tailor designed by Johan Anker to the R-1919 "New Class".
The S-1917 rule expired 1922. Several of the still racing R-1907 rule yachts were fitted out with Bermuda sail and reduced sail area. The handicap was removed and the yachts commenced racing in a combined class – “The Old Class”.
Go to Contents: “Snarken” history - part I and part II.
The scantlings for the S-1917 rule remained the same as for the R-1907 rule except for the dimension of the bow beam which were increased to 110mm for an Eight Metre, ref last paragraf under S-1917 articles (byggningsregler). Yachts laid down prior to Jan 1st 1918 to comply with scantlings for the R-rule of 1907.
Go to Contents: Appendix: http://www.snarken.page.tl/S_1917-articles.htm