Thanks to Jason Andrews for the J125 at sea footage…
The 41 foot J/125 is as close to high performance big-boat sailing one can find in a boat that’s manageable (yes, even with spinnaker) by two or three people. J/125 is like a street-legal Indy 500 car that’s easier to drive than the family sedan. Joy in ownership (and investment) is a function of time spent sailing. Time sailing depends on how easy it is to be off “on the spur of the moment” inspired by a beautiful day without having to organize 8-10 crew.
Easy to Go Sailing -How easy? Throw off the cover and hoist the mainsail on slides from the cockpit using a 2:1 halyard purchase. Cast off and sail faster under mainsail alone than most boats under full canvas. Unroll the jib and fly upwind. Ready to really take off? Pull out the retractable carbon bowsprit. Hoist the spinnaker in its sock. Then from the cockpit, slide the sock up the sail to deploy the spinnaker. Trim the sheet. Hold on to your hats!
To jibe, cast off one sheet and pull in the other. No need for anyone on the foredeck. To douse the spinnaker, cast off the sheet and pull the sock down over the sail from the cockpit. Stow when ready. Can you imagine the surprise of other sailors as you fly by them in 15 knots of breeze doing 10-12 knots?
Getting the Gun – One of the thrills J/125 owners experience frequently is being first-to-finish and getting the gun. The local crowd ashore assumes, as in other types of races, being first across the line determines the winner. J/125 upwind target speed is 7.8 – 8.0 knots. 10+ knots downwind is a daily occurrence. In fact we know of no other boat of its type and length that’s faster. Finding crew for weeknight and Saturday races is hardly a problem when you’re first to the party.
Stability & Seaworthiness- The sense of solidity and power when sailing the J/125 is explained by J/125’s extraordinary stability index of 143 degrees with a stability curve ratio of positive to negative areas of 12.5:1. This greater stability is combined with a balanced hull-form with proper amounts of reserve buoyancy forward, capable of safer & controllable higher-speed planing offshore in large waves and providing a wider steering groove upwind for sustained peak performance by average helmspersons. No IMS rule-inspired hull form can match the high 4.72 length to beam ratio of this sea-kindly yacht nor the reserve buoyancy designed into her bow sections. High length to beam ratio insures straight tracking in rough seas and light steering loads. Sailboats with fine bows and full midship sections are more difficult to balance and more likely to spin out of control in big waves.
What’s Unique About J/125’s Construction? The J/125 is built to ABS offshore specifications by TPI Composites using the SCRIMP resin-infusion process. Tests conducted by the US Naval Surface Warfare Center at Carderock, MD established that the properties of laminates produced by TPI’s patented SCRIMP resin-infusion process are superior to low-energy pre-pregs used by many custom boat shops and twice the strength of hand lay-up. J Boats was hesitant to enter the lightweight race boat market until something like SCRIMP/Carbon technology became available. In our judgment, SCRIMP construction greatly reduces the chances of warranty claims due to laminate failures resulting over time from pounding into waves and/or rig tension or ballast loads.
SCRIMP Process- The entire laminate is placed in the mold dry. A high vacuum eliminates any air voids, then resin feed tubes draw in only enough epoxy to “wet” the laminate. This is the TPI patented SCRIMP resin-infusion process. The last step in the process is to post-cure the hull and deck at 140 degrees in a closed oven. As can be seen from the chart, SCRIMP laminate properties in terms of compression strength, flexure, and tension are twice the strength of hand lay-up and significantly stronger than low energy (vacuum bagged) post-cure pre-pregs. There is no entrained air in a SCRIMP laminate. 1% void content reduces flexural strength by 10%. Note that 50% fiber content in a carbon laminate equates to 67% carbon/33% resin by weight. See the comparison of composite properties of low cost fabrication methods in the chart above.
Weight of Construction- after subtracting weight of keel plus 1000 pounds of rig, engine and hardware, J/125 at 2700 pounds is as much as 1500-2500 pounds lighter than competitive designs. Not all of this has to do with the J/125’s narrower beam. Hull & Deck Laminate Design- of the J/125 is stronger for its weight than E-Glass/epoxy laminates using slit CoreCell foam. J/125 uses epoxy with a combination Kevlar & E-Glass for the outer skin with two layers of carbon fiber (bi-axial & unidirectional) for the inner skin. The higher strength of these exotic materials allows a thinner, lighter skin than the equivalent E-Glass structure.