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An extreme case of not quite getting the boat where it needs to go in a gust of wind..


DandV

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3 minutes ago, DandV said:

Who said watching yacht races was like watching paint drying?

These new Am Cup boats really fly at times.

America Magic come unstuck at about 40knots while leading into the final leg in yesterday's Prada Cup Race against the Italian team.

Nobody hurt but the same cannot be said about the boat that was holed in it's heavy return to earth/water.

 

 

1610918705083.jpg

 

Edited by DandV
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I do so feel for them, having been in a similar position.

 

Wind conditions marginal, sea rather lumpy. tearing along on a reach on a 16ft Shearwater catamaran, crew out on the trapeze. Topped  a wave only to find that the next one in the wave train was "missing", where the wave was supposed to be was a "hole". The one after that however wasn't and we ploughed into solid water. 15mph to zero in an instant. Alas the solid water found a weakness in the joint between deck and hull, opened it up and split one hull down to the keel. We didn't sink due to built in buoyancy and a spluttering crew managed to disentangle herself from the trapeze and rigging.

The club rescue boat at about this time decided that the cats could look after themselves and anyway the bar was open so they packed up early. As it happened We were on the wrong side of a deep creek, decks awash and unmanageable, it was left to the kind offices of the then editor of Yachts and Yachting to take us on his cruiser.

The catamaran was eventually recovered and repaired but that is another saga.

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3 hours ago, Dr Bob said:

Drop the main!

 

......maybe the guy on the main sheet forgot to let it out?

 

Who designed that bote? No keel!

If you look at the foot of the main it has no conventional boom. The foot brushes the deck and follows its contour. This I believe is so no wind power is lost round the foot. The outhaul is attached to the track and it appears it is not possible for the main to be released further than the width of the boat or less.
Also if you watch the points of sailing there is never a run. It all appears to be close hauled or close reaches.

One particularly blowey race at Bala, sailing a Fireball, I made much better progress reaching up the beat rather than luffing all the time, sailing close hauled. Still needed to play the main however.

All fascinating stuff.

Edited by Ray T
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6 minutes ago, Ray T said:

If you look at the foot of the main it has no conventional boom. The foot brushes the deck and follows its contour. This I believe is so no wind power is lost round the foot. The outhaul is attached to the track and it appears it is not possible for the main to be released further than the width of the boat. 
Also if you watch the points of sailing there is never a run. It all appears to be close hauled or close reaches.

All fascinating stuff.

I’ve done a bit of sailing in the past, but I barely understood a word of that!

 

 These flying yachts are really amazing to watch.  There is a video somewhere taking on board;  those guys seem to work incredibly hard.

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18 minutes ago, Ray T said:

If you look at the foot of the main it has no conventional boom. The foot brushes the deck and follows its contour. This I believe is so no wind power is lost round the foot. The outhaul is attached to the track and it appears it is not possible for the main to be released further than the width of the boat or less.
Also if you watch the points of sailing there is never a run. It all appears to be close hauled or close

reaches.

One particularly blowey race at Bala, sailing a Fireball, I made much better progress reaching up the beat rather than luffing all the time, sailing close hauled. Still needed to play the main however.

All fascinating stuff.

To be honest, I've not watched any of this current series so not a clue about how the main is designed.

Sounds a bit boring just beating or close reaches. No gybes at the end of each leg? I guess too much coordination of crew to gybe one of those things. It was bad enough racing our 40 footer. No doubt they are using multiple wind speed sensors on either side of the main with a computer triming the sheet, outhaul and halyard (if it has them).

The best story I have of dinghy racing is rounding a mark with a boat in close proximity about to hit us with us in the right, and crew shouting to the helm, "bear away! bear away!...no bear away the other way!

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3 minutes ago, Dr Bob said:

To be honest, I've not watched any of this current series so not a clue about how the main is designed.

Sounds a bit boring just beating or close reaches. No gybes at the end of each leg? I guess too much coordination of crew to gybe one of those things. It was bad enough racing our 40 footer. No doubt they are using multiple wind speed sensors on either side of the main with a computer triming the sheet, outhaul and halyard (if it has them).

The best story I have of dinghy racing is rounding a mark with a boat in close proximity about to hit us with us in the right, and crew shouting to the helm, "bear away! bear away!...no bear away the other way!

I have been scared witless in the south Atlantic with waves bigger than our 55 Nick!

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They do gybe but keeping the main within the confines of the boat. Just my thought but I doubt if they could reach the speeds needed to foil on a conventional run.

For the non sailors these boats sail to what is called apparent wind as well as true wind. An example of apparent wind, if you are driving you car at 70 mph on a windless day, open the window and put your hand out the wind you feel is apparent wind caused by the car moving through the air.

These boats use apparent and true wind to get to the speeds they do.

Edited by Ray T
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1 minute ago, Ray T said:

They do gybe but keeping the main within the confines of the boat. Just my thought but I doubt if they could reach the speeds needed to foil on a conventional run.

For the non sailors these boats sail to what is called apparent wind as well as true wind. An example of apparent wind, if you are driving you car at 70 mph on a windless day, open the window and put your hand out the wind you feel is apparent wind caused by the car moving through the air.

The boats use apparent and true wing to get to the speeds they do.

 

The faster they go, the more apparent wind, so they go faster and get more apparent wind, so they go faster ..............................................

 

Sounds like magic !

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1 minute ago, Alan de Enfield said:

 

The faster they go, the more apparent wind, so they go faster and get more apparent wind, so they go faster ..............................................

 

Sounds like magic !

This is why Ice yachts can reach incredible speeds of course. Very little “rolling resistance.”

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1 minute ago, Dr Bob said:

Iced tea with a shot of rum is nice.

 

I did try Ice-fishing once, but never again.

I cut a hole in the ice and dropped the line in, a few seconds later this ghostly voice said "there are no fish here", I looked around and there was no one around, reeled in and rebaited the hook, dropped it back in and again the ghostly voice said "there are no fish here", I looked skywards with trepidation and said "Lord, is that you sending the message" to which the reply came .............................

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

No, "Its me, I am the Manager of the Ice Rink"

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43 minutes ago, Alan de Enfield said:

Never tried Ice yachts - land yachts are frightening enough.

In 1963 I knocked one together, used steel glazing bars as skate and a lug sail. it felt like it went like Billo on Filby Broads

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3 minutes ago, ditchcrawler said:

In 1963 I knocked one together, used steel glazing bars as skate and a lug sail. it felt like it went like Billo on Filby Broads

In the 70's we built one at the Gliding Club to use on days to windy to fly - went to a motorbike scrapyard and bought some Vespa wheels, one member had a mirror dinghy so we had the mast and sails, a seat out of one of the tow-launch cars and we were ready to start. Welded up a triangle of  1" x 2"  aluminium section, assembled all the bits and off we went.

 

Chased it down the runway with a car and clocked it at almost 40mph which is pretty fast with your bum 4" off the ground.

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10 hours ago, Ray T said:

Interesting to me they have smaller jibs in windier weather but do not alter the size of the main.

The foil looks like someones foots gone through the hull, skimming along on a welly boot.

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1 hour ago, Ray T said:

They do gybe but keeping the main within the confines of the boat. Just my thought but I doubt if they could reach the speeds needed to foil on a conventional run.

For the non sailors these boats sail to what is called apparent wind as well as true wind. An example of apparent wind, if you are driving you car at 70 mph on a windless day, open the window and put your hand out the wind you feel is apparent wind caused by the car moving through the air.

These boats use apparent and true wind to get to the speeds they do.

To put it more simply, on a run (ie wind behind) the fastest you can theoretically go is the wind speed, or very slightly less. But with the wind from the side (reach) you can go a lot faster than the wind, no theoretical limit. It’s like a tiddlywink, you press down a few millimetres and the thing shoots off sideways at high speed.

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A bit like an aircrafts wing shape, the curvature of the sail. On a reach the outer convex side is pulled by the suction of the wind, the inner concave is pushed by the wind, the suction is more powerful.  I bet all the crew were reaching on that boat too.

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42 minutes ago, ditchcrawler said:

In 1963 I knocked one together, used steel glazing bars as skate and a lug sail. it felt like it went like Billo on Filby Broads

We had one when I was based at RAF Ouston, Roger my boss clocked me at 70 mph and banned its use........which we did whilst he was around ?

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21 minutes ago, nicknorman said:

To put it more simply, on a run (ie wind behind) the fastest you can theoretically go is the wind speed, or very slightly less. But with the wind from the side (reach) you can go a lot faster than the wind, no theoretical limit. It’s like a tiddlywink, you press down a few millimetres and the thing shoots off sideways at high speed.

Nick, do gliders use apparent wind?

 

Apparent wind.jpg

Edited by Ray T
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1 minute ago, Ray T said:

Nick, do gliders use apparent wind?

Apparent wind.jpg

Not really. In the case of the boat, it is in contact with two mediums, going at different velocities (water and wind) but in the case of the glider, it is only in contact with the air. Its “relative wind” is merely its speed through the air. Whether or not that air happens to be moving over the ground, isn’t relevant. In other words, it operates solely in the frame of reference of the airmass.

 

There is a term ”relative airflow” but that is the angle at which the relative wind meets the wing - the combination of forward speed through the air and the vertical component caused by the combination of the glider’s natural sink rate and any vertical movement of the air (thermals etc).

 

B1EAF7C6-E871-48A9-A9E2-1A51A1DB2025.jpeg.17516b802145a43785b0c8522a6bd842.jpeg

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Actually when I said “not really” I guess they are in fact the same thing. The only difference is that with the reaching boat, the air is coming from the side to propel it along, whereas with the glider it is coming from underneath (relatively speaking, since of course it may be that the glider that is descending rather than the air rising). Otherwise, the principle is the same which is why some boats have solid aerofoil “wings” for sails, but pointing upwards instead of sideways.

Edited by nicknorman
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