2-27's and Spar Losses
(originally published in the Cal 2-27 Class Association Newsletter,
I got involved with the Cal 2-27s in 1988 (the year three boats
lost their rigs) when Roger Miller came to me for his new mast.
My seat of the pants analysis at the time was that the stock wire
sizes on the boat were too small and so I went one size heavier
on all the stays except the backstay on Roger's boat.
When Don Walder lost his rig in the Ong Regatta due to a broken
lower stay (the stay failed 1/2" inside the lower swedge fitting,
as so often happens on older stays), I decided to do a complete
spar and rigging analysis of the Cal 2-27 for my knowledge and for
the good of the class.
I approached Carl Schumacher, Naval Architect (the designer of the
Express boats) for his expertise. He told me that if he had a "righting
moment" (a calculation of a boat's sail carrying ability or stiffness)
for a Cal 2-27, he could do a complete computer analysis of the
mast and rigging. After a number of long distance phone calls, including
one to Bill Lapworth, it became evident that the Cal 2-27 had never
had it's righting moment measured.
I then contacted Dick Horn, former Cal 2-27 owner and official IMS
Measurer. When he heard what I was doing he volunteered his time
for the project, as did Carl Schumacher. Thank you both!
Dick used my Cal 2-27 to measure righting moment. Once we had the
calculations, Carl did more figuring, and plugged the numbers into
his computer program. He came up with some interesting results.
According to his analysis, the stay sizes on the Cal 2-27 are indeed
too small. Especially the headstay, backstay and upperstays. And
he said it wouldn't hurt if the lower stays went up one size as
well, as they are more heavily loaded than the upper stays.
Even with the larger wire, it is still necessary to replace the
standing rigging every seven to nine years. With the stock wire
sizes I strongly recommend that the standing rigging be replaced
in five, or at the longest, six years. If your rigging is older
than that, you're on borrowed time. Don Walder's rigging was seven
years old when he lost his rig.
Our boats have suffered way too many spar losses over the years.
Going up one wire size on all the stays should solve the problem.
Now, the plug - I have the specifications on Cal 2-27 standing rigging
down, if you want to order new stays from me and change them yourselves.
Or, I can do the complete job. Call me for details.
Steve Seal racing his Cal 2-27 Ex Indigo during
the 1991 Vallejo Race.