The wind started out ESE in the morning, moving south by late morning. Surprisingly, the wind "stayed" south (rare), although it was very shifty (one racer reported that they sailed around the committee boat without tacking once). Hard gusts (est. 8-10kts.) would roll off the south shore at approximately one minute intervals, coinciding with the presence of a cloud overhead. Lulls would be in the 4-6kt. range. My brother and left the beach on his first trip. The launch was clean and we got out past the pier. The wind was southerly, so we figured we'd do a couple of tacks west of the pier. Instead, we instantly rounded the boat up and dumped. In the next 90 minutes, we managed to get the boat sideways four more times, reaching down to the RVYC pier and back in a clear demonstration of what not to do. The only saving grace was that we took the boat into the beach with the south on our nose, making the landing hassle free.
Sunday was a great improvement (not in the weather, but in the sailing). Under heavy overcast with the rain coming down, the wind picked up and was gusting from the east and southeast. Despite gusts up over 10kts, we managed to both get wired and keep the boat flowing up wind. We had some trouble (my steering, specifically) down wind, but otherwise had a good sail. Both the launch and landing were again clean, but my turn was still at little early at the beach.Sailing Saturday.
Launching into the SE can be challenging because it requires a large bear-away starting from a standstill. The skipper goes on board to set the blades
- dagger board as far down as possible so that the boat pivots around it,
- rudder down to for steering through the bear-away.
The skipper then tightens the jib sheet as the crew forcibly pushes the bow around, pointing it away from the beach (basically on a beam reach). The crew may do this by working back along the wing and allowing the boat to swing around before climbing in. I witnessed a nimble crew climb over the wing, but if your balance isn't too good, it's best to come in over the stern. The skipper steers to keep the boat moving forward away from the beach.
During a capsize, there are a few things to note.
- The most important thing to remember is to unhook before the boat goes over (jumping from the top of the wing is fun).
- Don't step on the boom - step on the mast, or dive over the back.
- Try not to fall on the sails. If you do, try to fall on your back so that the hook on your harness doesn't go through it. Spread-eagle to distribute your weight on impact.
- The boat goes over pretty slowly if you do a standard "round-up" capsize. Once the wing is in, the boat doesn't rotate too quickly, so you have a bit of time.
To bring the boat back up, there are also a couple of things we found out.
- Don't put your trapeeze hook down anywhere - you make holes. When climbing on to the daggerboard, be very careful not to go on your belly.
- Having the boat turn turtle isn't so bad. Stand on the edge of the wing, lean back, and it will come back to horizontal.
- You can't bring the boat up if it is sideways to the wind (hull facing the wind). The wing acts like a sail, pushing the boat over. Turtle the boat and bring it up the other way, so that the wind will catch the wing and help you bring it up. Whoever gets on first will need to sprint to the windward wing to keep things flat.
- It can be a pig. Be careful not to get too tired.
When handling the boat through turns, it is incredibly
important to stay out
of the bottom of the boat. Every crash we had could be attributed to two things: poor steering and poor balance. This seems like stating the obvious, but is worth thinking about: before initiating a turn, remind your crew and yourself about position and balance. Either heading up or bearing away when under
powered will heat the boat up and both sailors must move out accordingly. It is too late half-way through the turn, and you'll be swimming. Heel to windward is necessary when bearing off, and OK when heading up. You also may be required to grab a trapeze wire to project further off the boat.
Trapezing changes the dynamics of the balance, and a little physics can tell you why. Three forces act to move and balance the boat: the driving force on the sails (pushing at the centre of effort), and the balancing force of the crew on the wing, and the daggerboard in the water (the last two are know as contributing collectively to the "righting moment"). Each of these forces can be thought of as a torque applied to a rigid rod fixed at the mast step. The torque applied to the mast and rigging by the sails rotates the boat to leeward, while the force from the foils and the weight on the wings rotates the boat to windward. Torque is given as the product of rotational force and distance from the centre of rotation. If there's a torque of 400N-m applied by the sails, and a 200N-m restoring torque from the foils, then another 200N-m is needed to balance the boat (The force due to gravity of a 20kg mass is roughly 200N: F = ma, where a = 10 m/s^2). This could be achieved by placing a 20kg mass 1m from the centre of the boat or 10kg mass 2m from the centre of the boat.
When the skipper and crew move out on to the trapeze, the dynamics change. The torque is no longer applied only to the wing, but also to the mast. Further, the force applied to the mast is further from the centre of rotation, which increases the torque. On the down side, the force is applied at an angle, and only the component of the force perpendicular to the mast will contribute to the torque. However, the fact that the length of the moment arm is greatly increased (i.e. where the trapeze is attached to the mast) is enough to make up for this.
Continuning from the previous example, if we take the 10kg that is placed at the edge of the wing, and support 80% of that mass on the trapeze, then only 2kg is left to contribute 40N-m of torque (of the 200N-m necessary). This leaves 8kg, or 80N of vertical force to be supported by the wire. If the wire is at an angle of about 36 degrees from the mast, and the vertical component of the tension force is 80N, then the horizontal component must be 60N. However, this 60N horizontal force is applied at a distance of 5m from the centre of rotation, for a torque of 300N-m!
By staying in place, and transfering your weight to the trapeze, you have increased the righting moment by 70%. You must be aware of the difference in effect of standing at the edge of the wing and trapezing at the edge of the wing to recognize the abrubt change in dynamics when you transfer to it.Sailing Sunday.
My brother's balance improved significantly on Sunday. Having had a chance to think about the sail on Saturday, we were much better prepared, and picked up a couple of good tips from other crews on the beach before we went out. The most important of these tips was separation of responsibilities for skipper and crew.
- Skipper. Upwind, the skipper drives and also re-trims the jib when the boat is settled. His other hand is free to go to the trapeze.
- Crew. Upwind, the crew takes the mainsheet, leaving his other hand free for the trapeze. When the boat is stable, he may hand the skipper the jib sheet.
Both people then have a primary responsibility to balance. The skipper (or helm) achieves this through focused driving. The crew (or sheethand) achieves balance through body movement and mainsheet control. Communication is essential - keep talking about what you're doing.
In contrast to the diagram on tacking from a previous post (which is in the style of older double handed dinghies), the helm does not hold a sheet through the tack. The jib is self tacking and doesn't need attention while turning through the wind. This leaves him a hand to establish himself on the wire at the other side of the tack. The crew is left with the responsibility of controlling the mainsheet and his body position to balance the boat correctly through the manoeuver.
Sailing upwind this way, we kept the boat flat and moving fast in the gusty easterly. We were both wired, and completed a couple of successful tacks this way before getting into trouble heading downwind. Having learned a good lesson on Saturday, our bear-away was well coordinated and positive: we moved out smoothly to keep the boat flat as the boat turned to leeward. Things went wrong when I lost control of the helm, crash gybed, and put the whole thing in. It took a while to get it up.
After getting the boat back up, we luffed upwind for a bit to rest, but ran out of ocean as we approached Kits beach. We made another successful bear-away and started to head back to Jericho. Here I finally experienced first-hand what makes this boat so much different: on a broad reach, the wind comes from ahead on the quarter. This is very
different. The boat sails faster than the wind, and since we were not adjusting the sails at that point, we noticed the following pattern
- We would start with the boat stable in a lull and the wind on the beam. The sails were trimmed and the weight balanced. The boat is moving slightly slower than the wind.
- A puff would overtake us and the boat would heat up. We would move quickly to windward to balance (I was hanging out by the trapeze) and the boat would accelerate rapidly.
- The apparent wind would move forward.
- The sails would luff and the boat would roll to windward - the boat would slow down and the puff would pass
- We would re-stabilize the boat in the lull with sails trimmed.
Ideally, we would be trimmed to stay in the gust or slightly ahead - as the boat accelarates, we would bring the jib and main in or bear away. However, after I had lost the helm a couple more times, and jumped off the back once (my brother saved the boat and I made the "swim of shame" back), we were more interested in getting back to the beach. This is definitely a lesson for the next trip.
On the landing, the wind was soft near the beach, and we had no real issues. As the helm, I've found it best to have the crew work the daggerboard and rudder blade up 10cm while I steer, rather than trying to bring the rudder out myself. It's also convenient to take the main down while in the water.Maintenance.
The dolly has eaten into the bow a bit, and the gelcoat needs repair. It hasn't been structurally comprimised, but it should get a little attention - one of these sunny days.