Hi,
Stupid question maybe but Google couldn't help me. Can someone tell me the origin / meaning of the half ton classification? They weigh more than half a ton so... 
Cheers.
Hi DrRog, The ton class boats were developed at the height of the IOR measurement system and take their names from the old Thames Measurement system. Under the ton class system of measurement there is a definition for each under the IOR rule. Multiple (or add?) up a load of parameters and if it is under a certain value it is a quarter-tonner, half-tonner etc. The smallest that was raced was the quarter tonner and the largest was the two tonner, but if you want to apply the rules you can make an eighth tonner or any other kind of mini tonner.
Ton class and most IOR type boats handle terrible, especially downwind due to their pinched in arses and all the other design tricks used to gain an advantage under the rule. eg. the reverse sheer transom.
It's all a bit like the metre class boats for we all know that a twelve metre yacht is way bigger than 39.37 feet. Basically, take the length x the breadth x the draft think of a number, divide by 2 and add one and voila! there is your formula yacht.
I wouldn't say IOR boats handling is terrible but it is true they don't track downwind as well as some later boats.
On the wind the S&S34 is better than anything of similar size and cost, new or old. I go for hours in all types of conditions without touching the tiller. Absolutely brilliant. On a reach a slight pull on the tiller with the gusts and she accelerates and tracks beautifully. Downwind I do have to steer but it isn't onerous. The Fleming vane and the Simrad TP32 handle it fine, up to 25 or so knots.
Hard spinnaker work with a quartering sea does require effort and concentration.
The MKII S&S34 with a larger spade rudder is much much better downwind.
Jon Sanders, David Dicks, Jesse Martin and Jessica Watson all managed to complete the most demanding downwind route possible in IOR boats, with less downwind issues than Kay Cottee had in a Cavalier 37, without taking anything from Ms Cottee who did a fantastic job.
I had a Peterson 42 which was designed to the IOR 2 ton rule.
Tiller steering, a powerhouse of a yacht to windward and off the wind could be steered with forefinger and thumb at times. Tracked beautifully.
My yacht is a halftonner, sistership to Zeus 2, overall handicap winner of the 79 Sydney Hobart, smallest yacht to ever win the race. My boat has done 5 Hobart's with the previous owners and the best result was a second in class. Its a delight to sail on any point. My previous boat was a Ben Lexcen quarter tonner, also easy to sail but with out the pleasant motion of the Currawong 30.
The half tonners and quarter tonners are undergoing a huge revival in Europe at the moment, particularly quarter tonners.
www.histoiredeshalfs.com/Intro%20Anglais.htm
The quarter ton and half ton boats under IOR were absolute rockets of the wind. They had flat aft sections and hence surfed the waves really we. Whiting and Farr 1/4 and 1/2 ton boats are brilliant...Not pigs !!
I have had to make similar vows.
Hey, thanks LooseChange and others. I went from that to find the Wikipedia entries for bother these systems. Appreciate other peoples' thoughts given on those specific boats too.
Cheers.
