TP 52' vs. IMS
52'
We know that IMS is dead here in the US, but it lives on
elsewhere, and at the same time the TP 52 class is becoming the
international boat de jour. SA contributor and Naval Architect Alessandro
Paganini has provided a nice little study of the two for us. Some
of these conclusions have already proven themselves here in the
states, but enjoy nonetheless. -Ed.
I'm
writing you because in last December my associates and I at Waterline
Yacht Design have been invited from a Yacht Club in Tuscany to manage
a small conference about the present and the future of Handicap
rules, focusing on IRC and IMS that are the two main rating rules
used in Europe and in Italy.
I've decided to prepare some materials also about Box Rules, as
here in Italy sailing magazines are full of renderings and articles
about "Italian designed TP 52'" that in reality are very
far from the reality of these box rules (someone presented a TP52'
without a coachroof and completely flush deck!! etc....), so owners
may misunderstand the reality and the power of box rules especially
the TP 52.
Anyway,
at the end of this meeting we presented a study in which we have
compared a TP 52 and an IMS 52' Race, preliminary designed by us
following the last "boxy shaped" hull of the IMS 2004
and the TP 52 rule.
I've contacted the rating office here in Italy and obtained the
IMS certificates of about 8 TP 52's, including the "new generation"
ones. Then we've designed some hulls with appendages and sailplans
to fit the box rules.
Our
tasks are:
- Is
the actual IMS (2004) a rule that forces designer to design slower
boats for their size?
- If
a TP52 will race in IMS regattas under IMS, can it win the race
on corrected time?
Well, comparing the results both of the TP52 and the IMS 52 under
the IMS 2004 VPP, and then of both boats with our VPP (under rating
rules and with proper hull and sail coefficients for both boats),
we found that obviously a T P52' is faster than a IMS 52', but a
TP 52' has the possibility to win a race in IMS corrected time as
well.
Following some numbers about our investigation and polars
of the IMS 52' and TP52' (the faster of the series of TP 52
that we have preliminary designed for the purpose of the conference).
Basically the datas are presented in the classic IMS format, with
speed
in second/mile. By comparing the Real performances (calculated
with non ims VPP) and the IMS
performances (with IMS VPP), it is clear that the TP52 is obviously
faster than the IMS 52' both with IMS VPP and with "Real"
VPP, but IMS underestimates the real performances of the TP52'....
Anyway, the answers to our questions, in our opinion, are:
- Yes,
but with the IMS 2005 rule changes faster boats in IMS will be
welcome.
- Yes,
a TP52' racing in corrected time with IMS could win the race.
PS: take into consideration that we set a wave average height of
0.5m, from the direction of wind, and this input has affected the
best performances of the boats, especially sailing upwind. But both
the boats are in the same waves conditions.
Regards,
Allesandro
Paganini
Waterline Yacht Design
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