PY Numbers

[JimC]

Researching PY, have come across first published Cherub PY number, which was 109 for the 12ft Cherub restricted Class with Cotton sails. The next year it went to 99 with terylene sails, and was called the UK Cherub 12ft restricted. The two numbers approximate out to 1187 and 1123 in modern currency, making an allowance for cotton sails. As you know its 920 this year.

By contrast the Merlin Rocket has gone from ~991 in 1960 and ~1033 in 1961 to 990 today,so clearly they haven't given their members too much to worry about with excessive obsolescence of boats...

[Torchy]

In the 70s the Cherub PY was 96, slightly faster than the Enterprise and Nat 12 which were 98.

Ent is now 1117 and N12 1077, so 12s have increased their speed by 9%...perhaps

if Cherubs were equivalent to a modern PY of 1094 in the 70s and 920 now it's a 16% increase, except 920 some think is generous and 890 is perhaps closer and about 3% faster. Are modern Cherubs 20% faster?...sounds about right, maybe.

505 was 81 in old money and 902 now which puts it in the 16% ballpark but going from slightly faster than a Nat 12 to about as fast as a 505 (depending on course and conditions) is pretty impressive.

[Tim Noyce]

I think that the speed increase of the moderns boats is nothing short of phenomenal really. Not so much top speed, but the speed increase in lower wind speeds. They get up and go a lot sooner, which means that on average they are a lot faster.

This is noticeable in that in the Bistro we were around a lap slower in a 4 lap race at the nationals (so 25% slower), and in a previous nationals Kate sailed with my Dad in 2303 and they were probably doing 2 laps for every 4. (this is not exactly representative, as the new boats are of their time whereas the old ones are just that... old boats!)

[Torchy]

Absolutely Tim, the way the new boats twin wire and start planing very early upwind is astonishing.

[simon_jones]

If you think that  in 2005 Loco was considered to be very narrow in the bow, it shows how much the designs have changed.

[MK]

If you think that  in 2005 Loco was considered to be very narrow in the bow, it shows how much the designs have changed.

I don't think it was, Locos design concept was always a more forgiving platform to be able to really drive the boat hard with the introduction of twin wires