Videographer Warner Nickerson got these terrific drone shots of a J/111 doing some testing with her Large Roach Headsail. A Large Roach Headsail (LRH), or “Tweener,” is defined as having a mid-girth between 50-75% of the foot length. There have been a number of changes in various rating rules in the last couple of years. To understand these new sails, it is good to understand the history. The original Code Zero was intended to provide the power of an overlapping genoa for reaching on boats that were rated as having non-overlapping jibs. Boats got a huge rating credit for switching to non-overlapping jibs. When sailing “up wind” the efficiency of high aspect sail plans made the rating credit worthwhile. The problem was when boats that were optimized for windward-leeward races went distance racing. In distance races most legs are reaches. Boats with non-overlapping jibs have a big hole in their sail inventory between the jib and their flattest spinnaker. The Code Zero was an ingenious work-around that built a very flat sail for reaching that worked like an overlapping reaching jib but measured as a spinnaker.
The rules define a spinnaker as a sail whose mid-girth measurement is equal to or greater than 75% of its foot length. This concept has gone through many iterations over the years, but the always present issue is that the sails are almost always better with a mid-girth closer to 55-65% vs. the required 75% to make it a spinnaker. With this in mind, the ORR and ORC rules now allow and rate these smaller mid-girth sails. Under both rules, these sails only affect ratings for races that are not scored under the Windward-Leeward ratings. These sails are also called “Tweeners” as they are sails that are in between a jib and a spinnaker.
Tweeners are a bigger, more powerful sail than a Jib Topsail. Jib tops have to measure in as a genoa and the LP measurement can’t be bigger than the LP of the boat’s biggest jib and the luff length can’t be longer than the luff length on the biggest jib. Therefore, on boats with non-overlapping genoas, the jib top is a very tall and skinny sail, which is not the greatest shape for reaching. For more information about jib tops, click here to go to chapter 4.9 of the UK SAILMAKERS ENCYCLOPEDIA OF SAIL.
While this video is technically well done, it does not show the Tweener being used at its most efficient wind angles. These sails are designed for close reaching. If the boat had sheeted in and headed up, she would be much faster.
The Code Zero has become the most confusing term in modern sailmaking since the sails can have many different foot lengths. UK Sailmakers is here to give you the confidence to make the right sail buying decision. In order to find out what sails are available, contact your local loft and they will work with you to develop a tailored solution and determine whether an LRH or Tweener, Code Zero, Jib Topsail or any other sails might improve your distance or coastal racing inventory.