J/111 Blur³ | upwind sails

This is a English version of “J/111 Blur³ | segel”.

Naturally I got some questions regarding our sail inventory; sails, materials, crossovers etc. But I wanted to do a couple of races before I wrote an article. In the first part I’ll focus on the upwind sails, and then I’ll cower our downwind inventory in a separat piece.

We choose to go for the One Design sails for main and jibs. North CSD (Class Sail Development) have spent lots of time and effort on the designs, and have experience with the J/111, at least in the US. We did the same choice on the J/109 and have been very happy with what we got, so why change a winning formula.

When it comes to material, we were one of the first boats in Scandinavia to go with 3Di in 2010, and we made the same decision again. We’ve raced them hard for two seasons and they show almost no signs of wear and tear (even in the hands of amateurs) and they’re still very fast. Two weeks ago (above) we won the Marstrand Big Boat Race with the J/109 and “old” sails.

Mainsail 3Di 780 (Dyneema/Carbon) 14,700 Dpi
The main are on maximum measurements within the class rule, which means a pretty big roach. Many boats in UK, France or the Netherlands decide for a smaller one to optimize for IRC, which might be ok when yoy race in more wind. We wanted as much power as possible for light Swedish summer conditions so the one design setup worked great.

We configured the reefs differently. A pretty big first reef and then a ISAF Offshore Special Regulations heavy weather reef that shortens the luff with 40%, which will be useful when racing shorthanded. On the J/109 we hade one racing main with one jib, and a shorthanded/cruising one with this configuration and it worked out very well. Shorthanded it’s important to be able to shift gear quickly and reefing might be a safer choice, compared to a headsail change, to survive a front or manage the last 30 minutes of a leg. FFor this reason we also choose sliders instead of luff rope.

Jib 1 light/medium 3Di 780 (Dyneema/Carbon) 10,850 Dpi
The light/medium jib is on maximum measurements according to class rules, and covers 0-10 knots TWS, even if it’s built strong enough to sustain 14 knots. The sweet spot seems to be around 4-6 knots and we have to work hard to get full power throughout the range, and de-power at the upper end. The J/111 is very sensitive to trim (compared to J/109 and other cruiser/racers). Especially in-hauler settings seems to be crucial. We’re getting the hang of it and are becoming more and more comfortable, especially at the upper end of the range.

Jib 2 medium/heavy 3Di 780 (Dyneema/Carbon) 14,700 Dpi
The medium/heavy jib is also on maximum measurements according to class rules, and covers 10-20 knots TWS. This is almost the same jib that we loved on the J/109, but with less shape for the J/111. This is the workhorse when we race double handed, and we hope to be able to get it to work 4-18 knots in flat water (we mainly race in the archipelago) even if we’ll have issues with acceleration at the lower end.

Right now we’rte working hard to increase the “crossover zones”. To get #1 to work in 12 knots and the #2 in 8 knots. This overlap will keep the number of changes down.

This jib have horizontal battens for racing with a full crew (not using the furler) and the possibility to use roller battens for using it with the furler when racing shorthanded.

Heavy Weather Jib ORC Max 3DL Marathon 600 (Aramid) 22,400 Dpi
The heavy weather jib is sized to fit ISAF Offshore Special Regulations and should cover 20-30 knots TWS. We find that it works great down to 16 knots in flat water and it will be used a lot since the J/111 doesn’t need much power to go fast in a blow.

We have the choice to run it with, or without, horizontal battens on the forestay. Also it has an integrated luff cable allowing us to use it on a ProFurl just inside the forestay to be able to shift gears without a headsail change shorthanded. From full main + #2 jib in 4 knots to two reefs and #3 jib in 30 knots should be possible without a headsail change. Here we’ll have to spend some time figuring out the pros and cons of the different combinations.

Another “special” is a second clew about 1 meter above the normal one. This will be useful on survival reaches and might work as a heavy air jib top.

Storm jib
This is cut with a little more shape than usual to be able to work as a staysail inside the code 0. Also it has it’s own luff cable so it can be set by itself just behind the forestay.

To summarize. A proper one design inventory to be able to get 100% out of the boat fully crewed. “With a twist” to be able to use the same sails in different ways for shorthanded versatility.

There’s both pros and cons when you’re working with a big sailmaker and different groups within their organization. On one hand you want a dialogue with your local contact, in my case Henrik Ottosson and Patrik Erlandsson. On the other hand you wan’t to reap the results of extensive research and testing that the CSD – Class Sail Development can offer.

When racing an international one design, especially in a rapidly growing class like the J/111, chances are that that lots of people put in time and effort to figure that boat out. The tricky part is to get hold of that information. Here Larry Leonard, the J‐111 Class co‐leader, organized the first J‐111 North two‐boat tuning, 3 day sail testing session in Annapolis. Focus was mast rake and pre-bend to optimize for v2012 designs, rig tensions, in‐hauler settings, crew weight placement and crossover for L/M to M/H Jibs. Extremely helpful for us that’s new in the class.

It’s fascinating to see how thorough they are when it comes to a new class, even if it’s not VOR or AC. As input there’s detailed measurements from J/Boats and the rig separated into individual elements with specific properties as defined by Hall Spars. Rig docktuned in MemBrain to check luff curve and prebends before importing sails.

Sails are designed and imported to the rig. Class rules are read and suggestions made to J/Boats

Sails and mast divided up into individual mesh elements with exact yarn properties, tube properties, wire stiffness, etc modeled in Finite Element Analysis. Starting yarn layout chosen from 3DL’s database of 2,200 commonly used yarn layouts, dpi ranges and fiber comb configurations. Yarn layout imported onto sails and rig.

In our case they did a 3Di layout, but the principles are the same. More on that process here.

Starting pressure distribution added to sail models.

Sail designer carefully checks sails in CFD for resultant forces and heeling moment. This is checked against the boats target speeds and heel angles to make sure appropriate trim is made to the sails.

Trim adjustments made to sail and rig.

Flying shapes checked by North Sails CSD, sales and design team and models confirmed, sail shapes refined.