Category: Model Yachting

Wireless Mast Camera

Jari got a small wireless camera operating on 2.4 GHz and mounted it at the top of the mast on his no2 rig. With the bulky power connector removed and a longer wire for the 9V battery which is under the deck the camera weighs about 20g. Now we used a preliminary aluminium angle to hold the camera, but a better carbon arm should be made for next summer.

This camera is the variant where you can plug the receiver straight into a laptop via the USB port. The receiver even gets its power via USB, so no extra power supplies needed in the field. Range seemed good, and image quality was OK - probably now limited more by the compression used in the PC than by the camera.

The idea is to look at how the sails, mast, and whole rig behaves from on-board images. It's probably hard to say something from a single video or frame, but if some parameters (say shroud height) is systematically varied on the same boat in the same conditions then we're hoping this could provide some insight into what's going on.

More Marseilles pics

Here's David Potter's GBR20 Lintel. Note how high the gooseneck is. The boat is not so fast in light weather, so this is an attempt to get the rig higher up and gain some speed in the light stuff. Home-made gooseneck with laser-cut stainless steel bearing holders at the top and bottom (note adjustable holder at the bottom), and a carbon swivelling part. David also has the auto-adjusting cunningham arrangement with the line threaded around the mast. It's not very visible from this picture, but the mast-ram is attached to the mast - so there are three mast rams that stay with each rig, and the correct adjustment stays with the rig. Gelcoat on foredeck has been left out to save weight.

laser-cut ss spreaders. They look nice and work well but are not detachable for transport like the normal ones. They rotate to be parallel to the sail, but still stick out a bit more than normal spreaders do.

laser cut hooks for jib and toppinglift, and below that a separate hook for the shrouds. Note how low the jib attaches compared to the middle measurement band - that's because the mast and mainsail are higher up due to the high gooseneck. Rake adjustment with multiple holes in the mast.

Laser cut ss mast crane.

A box full of laser-cut parts.

Pierre gonnet had some fittings on display.

Gooseneck fittings.

some black bottlescrews for shroud tensioning.

Finally a few pictures of Brad's boat.

no1 rig jib attached to the deck with a piece of string through the deck eye. An alternative to the through-deck tube which is more elaborate to build.

A view of the rig. Shrouds attached to the same kind of hook (covered with tape) on the front side of the mast as on GBR20, but much lower on this boat.

IOM details from Marseilles

Here are some detail pictures from last week that I thought were interesting.


Graham Bantock's Topiko. Note quick-release bottlescrew and deck-fitting far right. Also note how the cunningham is threaded through a plate with holes around the mast. I think this gives a variable cunningham tension (tight on the beat, looser on the run?)



Recessed jib-sheeting hooks. With the new sheeting system and the arm-winch configuration there's no endless-loop or other sheeting lines on the deck. Just the jib sheet very neatly coming out of a PTFE fitting in the foredeck. Many boats do not use a separate sheeting position for the no2 and no3 rigs, so I guess threading the sheet under the metal wires for the no2 and no3 rigs is optional.



Same kind of recessed wire-hooks for no2 and n3 rigs. The no1 rig uses a piece of Dyneema that attaches to the bottom of the boat and comes up on foredeck through a tube. I wonder if the added complexity for building this is worth it? Sheeting angle adjustable with a bowsie.



John McPherson's very serious looking rigbox. My own is similar but this one is deeper so could probably fit two sets of rigs.



A Gearman, breathing version of a rigbox.

Craig Smith sailed the same Obsession prototype that he won with in Mooloolaba, and Simon Kellet's Obsession boat pictured here is the first (and so far the only!) production boat.



The round Decor hatch with all the radio installations neatly in one place. The battery even has connectors on the bottom of the fibreglass casing - just press it down and it connects.



Note how much the rudder tube leans forward. I wonder what this does to the function of the rudder. Any boat designers want to comment below?


Craig Smith's no1 rig jib. Note how the topping lift bowsie is to the left in the picture and the topping lift is threaded inside the boom and comes out at the end. The pink elastic keeps the topping lift tight so it doesn't catch the spreaders. There's only one sheeting eye in the deck that is used with all three rigs. Similar to GBR-95, the cunningham is threaded around the mast to give an auto-adjusting effect. Lester Gilbert has two interesting notes on auto-adjusting cunninghams here and here.



Forward end of Craig Smith's no1 jib. Craig is also using the Dyneema thread idea for the no1 rig jib swivel. Although putting in the tube is one more job when building the boat you do get a useful stiffening of the foredeck at the same time. Craig seems to use the same deck-eye for both the no2 and no3 rigs as there is only one attachment point aft of the no1-rig swivel.



Craig's very neat and minimal top jib attachment. The overall rake of the mast can be adjusted by moving the hook up and down on the mast. Note how the topping lift and the jib attach to the jibstay. There's no shroud attachment point in sight in this picture (compare that to pictures below) - which means Craig uses a much lower attachment point than Graham.

I'd love it if someone took measurements and wrote them up like I did in 2003.


Graham's boat again with another view of the new quick-release bottlescrew. Note that Graham doesn't use adjustable sheeting attachments any more. I think it's because the arm-winch is significantly more precise than a drum winch, so there is not much variability from day to day or month to month in how far the sails come in when you set up the boat.


Graham's top jib attachment with a bowsie for controlling mast rake. Note use of the flat steel tape for the topping lift. The same steel tape is used for the shrouds, which attach just below the jib-attachment point. Compare this to Graham's Mooloolaba boat where the shrouds both attached to the same point on the front side of the mast. (more from Mooloolaba here)



Brad Gibson's no1 rig jib with a nice cnc-laser-cut steel hook for the jibstay and the toppinglift, and a piece of string pulling the topping-lift forward and clear of the spreaders. Again no shroud attachment point in sight - which must mean that Brad uses a similar low-shrouds configuration as Craig.

I have some more of these which I'm hoping to get online soon, in particular some pictures of the Lintel and more cnc-laser-cut fittings from David Potter.

If anyone has some pictures that they think would be a good addition please feel free to comment below or email me directly!

Racing Day 6

Final day of the 2007 IOM Worlds today, two more races completed. Much colder today!

#1 rig wind coming and going from different directions at 0900.

1028 22D finishes. The first two heats use courses with starboard roundings, but later the race committee switches to port roundings.

1048 22C finishes

1132 22B finishes

1147 22A finishes

1240 23D finishes

1340 23A finishes. New world champion Brad Gibson wins the last race!

It takes until around 1530 before the jury resolves about three protests arising from the last A-heat. During the prize giving it starts to rain for the first time during the week.

Final results here.

Racing Day 5

0900 No wind

0929 an attempt to start 17A is made, but there's still not much wind

0951 now there is a bit of wind and 17A has one general recall before starting

1019 18E general recall

1021 18E starts, but the wind dies almost completely. Most boats finish within the time limit, but a few are too late.

1123 18D finishes. Still very little wind, shifty with a lot of wind holes.

We wait for wind. The wind now comes from the north as the previous day. Nowhere near the same strength as yesterday though and we have #1 rigs for the whole of today.

1214 18C has one general recall before starting at 1216 (finishes at 1226)

1230 18B has one general recall before starting at 1233 (finish 1241)

1248 and 1251 18A has two general recalls

1257 18A starts under black flag and three boats are caught over the line so need to retire immediately. Finish at 1304

1313 19E start

1410 19B finishes

1427 19A starts

1504 20D start

1522 20C start, finishes 1531

1550 20B finishes

1614 20A finishes

1639 21E finishes

1652 21D starts

1710 21C starts

1727 21B starts

1805 21A has two general recalls and so again starts under black flag. Three boats are again forced to retire immediately.

Results hopefully to appear here.

Racing Day 4

Four more races completed today with only the A-heat of the fifth race to sail tomorrow morning (we then have 17 completed races all together). Results after 16 races here.

0900 lots more wind today, looks like it's going to increase, but #1 would still be the choice at 0900. It's coming from the opposite direction compared to the first three days, and so we start at the bottom of the course between the leeward mark and a starboard starting mark. This makes for a much longer first beat up to the windward mark, which does reduce the number of incidents. However the leeward mark was quite far away, so judging the starboard lay-line right is not easy.

0953 13E finishes. Four boats use no1 rigs, the others are in #2

1000 13D finishes. Lighter now with just one #2 rig on the course

1037 13C finishes. Mostly #1 rigs now. I make a bad start, and then the wind dies completely on the second beat. I have the #1 trimmed for lots of wind, and so it doesn't work great when the wind dies. Also my counterweight on the jib is too far in (straight from the rigbox), so the jib doesn't want to goosewing in the light stuff. Must build/modify rigbox where rigs are stored in racing condition.

1052 13B finishes

1108 13A finishes

1201 14D finishes. Now stronger #2 rig weather. Boat is very hard to tack (need bigger fin and bigger rudder?). I haven't yet found the optimal mast position and/or rake for the #2 rig and so the boat feels a little dead on the beat. I can steer both up and down, but the boat doesn't find that optimal groove by itself.

1218 14C finishes

1240 14B finishes. Most skippers are using #2 rigs, but now the wind is getting stronger and we see lots of diving on the runs and problems with tacking on the beats.

1254 14A starts. About 50/50 divided between #3 and #2 rigs now

Lunch

1423 15D finishes. Not a great start for me, and although the wind is strong there are big shifts and holes where there's no wind. I manage to catch the wrong shifts and holes on the long beat... Balance is not great with the #3 rig when there is too little wind. Have to steer the boat upwind to find the correct height.

1458 15B finishes. Almost everyone is using #3's now and for the rest of the day.

1506 15A starts and finishes by 1515

1535 16E starts but is recalled once

1613 16D finishes

1638 16B starts

1711 16A finishes

(not much notes from race 17)

1832 17B starts. Starting to get lighter again with some #2 rigs appearing on the course.

Tomorrow begins with 17A.

Racing Day 3

Five more races completed today in the same shifty/gusty over-land no1 rig breeze as the two days before. The first beat is a bit longer today, and the course is made longer by having a long final upwind beat and finishing between the top-mark and the offset-mark. Results here.

0926 8E starts, general recall

0930 8E starts and finishes 0938

I've raked the mast more upright and found some kind of balance with the no1 rig. The boat seems much better offwind, and I move up from 8D to 8C.

1018 8C finishes after two general recalls

1020, 1022 and 1026, 8B starts three times, recalled twice, B-heat finishes 1035

1045 8A starts and finishes 1053

there is a protest hearing

1116 9E

1136 9D

1206 9C. The course is somewhat skewed and especially on the last long beat to the finish you need to make sure you are not on the wrong side of the course. This is not easy as the wind shifts around and what worked on the other two beats may not work on the final upwind to the finish.

1211 and 1214 9B starts, general recall, starts again and finishes by 1223

(no notes from 9A)

1300 10E finishes

1312 10D starts

there is a delay (?)

1405 10C finishes. I'm seventh, so instead of going up to B I'm called for measurement (no problems with my boat were found). I mess up a good start and a good first leg on the second beat by being on the wrong side of the course. Again the side that was lifted or preferred just a minute ago can't be relied on being good just moments later.

1433 10A finishes.


An A-heat start

1550 11C finishes. I took a small risk and changed down to no2 rig (me and one other boat did). Not a great heat since the wind was not too much for the no1 rig for most of the time. I did pass 2-3 boats that were nosediving on the second run, but my no2 rig doesn't have good balance upwind when there is too little wind.

1622 11B starts

1635 11A starts and finishes by 1644

A course where the starboard right side of the course was blocked by land and the starboard lay-line was very short made top-mark roundings challenging and we saw a lot of incidents here today.

1703 12E starts

1716 and 1718 12D starts but is recalled, starts again

1745 12C finishes. I've stayed in the C-heat for the whole day now...

12B and 12A sail before racing is over for the day. The event dinner at the YCPR clubhouse follows.


Another situation (A-heat) at the top mark where it is very tempting and easy to go upwind on starboard, but then you need to find a way back to the mark on port while avoiding the row of starboard boats.

Racing Day 2

Race 4 was completed today, and we sailed three more races in sunny, light, and shifty/gusting no1 rig weather.

0928 race 4C is done. I make a good start and round ca 4th, but the first reach doesn't go too well. I try to protect the inside, but that means the windward boats are stealing my wind...

0953 4B has a one general recall and one abandoned race.

1050 5E starts but has a general recall. Starts again at 1052 and finishes by 1100

1114 5D starts, general recall

1117 5D starts, general recall

1123 5D starts, general recall

1135 5D starts and finishes by 1143

1218 5C is done. I make a bad start and collide with a boat on the first beat. Very skewed start line.

1241 5A starts and finishes by 1247

A protest hearing follows, while everyone seems to be having lunch.

A skewed start line and first mark made for some interesting tactics for the first beat. Here it's possible to lay the top mark(blue/white) on starboard from the starboard end of the line(red/white in the background). Making a safe start further down the line meant you were coming in on port against a wall of starboard tackers...

1333 Heat assignments for race 6 posted, and 6E starts at 1343 and finishes 1350

1426 6C is done. I start in free wind, which means not at the 'hot-spot' near the starboard flag. But that carries me too far left on the first beat and there's no way back on port while facing a row of starboard tackers. Also I make contact with two marks which means two penalty turns - not a very fast way to sail...

1431 and 1434 6B attempts to start but is recalled twice

1436 6B starts and finishes by 1443

1452 6A starts and finishes at 1458

A crowded first-mark rounding by the A-heat. One- or two-tack first beats and a set of twenty closely matched skippers lead to this. To improve racing I think we need bigger courses that create more separation before the first mark. Compare this picture to the sequence of pictures of the same phenomenon from Mooloolaba (.mov QuickTime format)

1512 there is a protest hearing

1624 7E starts but is recalled. Starts again at 1629 and finishes by 1638

1700 7D is done. I make a bad start and sail a bad offwind leg. Maybe I need to rake the mast more forward for tomorrow, since I seem to be consistently loosing on the reaches and runs.

1704 and 1707 7C starts but is recalled twice

1713 7C starts under black flag and finishes by 1722

there is a protest hearing

1810 7B is done

1817 7A starts and finishes by 1826

Brad Gibson (AUS), sailing a Widget, leads after 7 completed races.

results after 7 races are here.

Racing Day 1

Three full races (E-D-C-B-A) and two heats (4E and 4D) sailed today at the Worlds. I've forgotten just how much waiting these big championships consist of... for fun I wrote down some times on paper:

0900: Yep, my prediction from yesterday is correct. There's no wind and the AP-flag is up.

1042: The E-heat of the seeding race is done in a gust of wind. However the wind dies out and changes direction, so more waiting.

1131: D-heat of the seeding race. I make an OKish start, but approach the first mark on port with a row of starboard tackers in front of me. Also a collision at the leeward mark, so I'll race in 2E...

1156: B-heat of seeding race

1233: The A-heat of the seeding race finishes.

1322: The AP-flag is again up while results are calculated.

1340: Race 2, heat E is finished. Again my start is OK but finding a way around the crowded first mark proves challenging. More collisions and more penalties. I'm stuck in E for race 3 too...

1351: 2D starts.

1423: 2B starts. The leading boat finishes at 1428 for a heat-time of ca 5 minutes.

1438: 2A starts. Leading boat finishes 1445, heat time ca 7 minutes.

1507: A protest hearing (probably related to the A-heat?)

1535: more boats called into the protest room.

1555: 3E is started but abandoned

1604: 3E starts. I'm sixth, so can take advantage of the new HMS system where the six first go up into the next heat.

(3D also goes OK for me, I'm fifth so I move up to C)

1703: 3C finishes. I didn't sail great, but I stay in the heat and start in 4C tomorrow.

1723: 3A starts and the first boat finishes by 1729

1739: again there is a protest hearing after the A-heat

1818: 4E is started but results in a general recall (there were many of those today, probably due to the skewed starting-line which made the starboard end highly favoured in most heats)

1820: 4E starts and finishes by 1828

1847: 4D, the last heat for the day starts.

This then is roughly the daily schedule that we shall follow for the next four full racing days, with Wednesday as a lay-day in between, and then there's Saturday, the last day, when racing is only from 0900 to 1300.

Full results here.Â