Wednesday, 31 January 2018

Cool Runnings Open 7.50 / HP30 FOR SALE

FOR SALE
Open 7.50 / HP30 “Cool Runnings” DEN 004
Hull nr. 004 build by JPS productions
Sales Contact: jochem@boatspeed.info 
Price: EURO  45000,-  or GPB 39.000,-(incl. VAT)


Description

Very well maintained Open 7.50 with excellent race track record and comprehensive inventory of sails and extra’s. She comes with a road trailer with storage for equipment and sails. She sports the latest set of North Sails from April 2017 which have only been used for 5 days.

This boat had several extensive refits with the last one completed in 2016 which included a full re-spray and high finish of hull and foils. This Open 7.50 has had an exceptional track record winning trophies in events like Spi Ouest, Tour Belle Ile and twice winner of the infamous Cento Miglia. She also turned eyes in the new UK HP30 class not only winning races but also showing her pedigree as the smallest boat taking line honours in the class consistently.
She is a true thoroughbred and the current owner’s attitude towards excellence is clearly displayed in her finish with remarkable detailing. She has the latest type of EVA foam based non-skid in the cockpit and is very well maintained throughout.
Footage of her in action on the following links:


Inventory
Equipment:
  • Mecanorem trailer with storage boxes (x2) and sail storage tubes(x2), Custom hull cradles and equipped with all the legal requirements for towing her including a revolving warning light. Trailer has been well maintained with new tyres 2012, new brakes, brake cables, tow hitch and wheel  bearings in 2016.
  • Comprehensive  cover (2012) which can be used during transport as well.
  • Tack Tick Racemaster with Boatspeed & Compass  heading. Includes deck mounted solar charging panel.
  • New Harken winches (2015) and 2x winchhandle.
  • Rudder transport covers.
  • New rudder bearings and pins 2017.
  • Extensive set of spares and spare running rigging.
  • Spinlock tiller extension.
  • Onboard waterproof toolbox with handtools and  race spares.
  • Aluminium keel lift serviced 2017 with dedicated storage on trailer.
  • Spare sail battens.
  • Gennaker drop bag for cockpit with fastenings.
  • Loose Rigging tension gauge.
  • 2016 ORC rating certificate and 2017 IRC rating certificate.
  • Open 7.50 Class compliance certificate
Safety equipment:
  • Anchor with chain and line in waterproof bag.
  • Bucket and bailer.
  • Paddle with adjustable handle.
  • Hand bilge-pump.
  • 4x red Handflares.
  • Safety mirror .
  • First Aid set.
  • Safety knife.
  • Foghorn.
  • 5x Spinlock Zero Buoyancy aids (2013)
Sails:
Sail
Brand
Year
Condition (1-10)
Mainsail
North 3DI Raw
2017
10
Genoa Medium
North 3DL
2017
10
Genoa Heavy
North panel
2017
10
Gennaker AP
North Superkote
2017
10
Code 0 / A5
Incidence Panel
2013
9
Genoa Medium
North 3DL
2015
9
Gennaker AP
North Superkote
2015
8
Gennaker AP
North Superkote
2012
7
Mainsail
Incidence
2013
8
Genoa Medium 
Incidence
2013
7
Genoa Heavy
Incidence
2013
8
Mainsail 
Incidence
2009
5
Genoa Medium
Incidence
2009
5
Genoa Heavy
Incidence
2009
5
Various other training sails (+/- 14 sails)
Incidence, Epsilon, North, Le Bihan, Technic Voile, Daoulas
2000-2008
unknown

Monday, 29 January 2018

CFD v Reality

CFD image courtesy of Mario Caponnetta

Sunday, 28 January 2018

Foiling high speed stalls

Team Cool Runnings (CR4) experienced a high speed stall when foiling in the Solent in late October 2017.

We've been studying what could have caused this as it happened at a top speed of about 34 knots in relatively calm/flat waters of Southampton river.





This picture shows the sudden speed loss as the cavitation forms around the foil and quickly develops into a massive speed brake as the volume of the air bubble increases.

The picture (courtesy of Mario Caponnetto) below shows quite well one of the root of the causes. As
the cat accelerated she also flew very high and with that the drift/leeway increased drastically causing a very high angle of attack on the lower leeward end of the v shaped foil carving through the water. In CFD simulations you can see in red the area which is most prone for starting cavitation. As we reached higher speeds, quite suddenly in a gust, the rake settings were to high and coupled with the our wind proof trampoline*it lead to a bow up high ride. This increases the leeway dramatically as ever less surface of the asymmetric shaft side of the foil is supporting the high side forces of the rig. This is even made worse by the shallow apparent wind angles these boats endure downwind ( less than 30-40 degr AWA).

In layman terms we went to fast flying to high. The foil spat the dummy at us when there was hardly any lateral area left for either uplift or stop us from skipping sideways. Lesson learned.......fly low = fly save



*  Windproof trampoline assist our endplate effect of our Aero skirt and minimises  losses and tip vortex around the bottom of the mainsail.


Wednesday, 24 January 2018

Numbers & Graphs.......optimising for 2018 ORC/IRC Worlds The Hague

With the unique combo of the ORC as well as IRC rated Worlds coming up in July 18' in The Hague there are some interesting challenges for those who want to optimise their yacht. Where each of the individual handicap rules has its own perks now the game will be find the best road between these two offshore handicapping rules.

Jochem (aka The Boatspeed Doctor) explains; " The question is not to optimise for either rule but to find a medium which allows you to keep average good scores in both. Each boat will be rated both under IRC & ORC. The scoring will be determined by equally weighing the score of the yacht in both rating system for each race. This throws up a few challenges as one is time on time and the other time on distance, one is a constant multiplication factor while the other varies with wind strength and course type. The key is to determine which of the two rules creates the biggest deviation relative to the boats true performance, in which wind range and on what course type. It's all about eliminating high scoring races in either rule coupled with a risk management strategy for the expected fleet in each class."