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Old 15-07-2007, 14:13   #1
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Cat with bulb bow entry

Anyone know of any trials using this idea?

Intriguing in my thoughts but I am no engineer or marine architect or calculus user or much of anything else either I guess.......
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Old 15-07-2007, 15:28   #2
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Loch Crowther has used bulb bow's in his designs.

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Old 15-07-2007, 17:21   #3
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Some early Prouts had them. A guy I know circumnavigated with a Prout that had them. He tells the story of hitting a semi-submerged tree or board while crossing the Indian Ocean. This knocked one of the bow bulbs clean off the boat. I asked if he noticed any difference in sailing or motoring and the answer was....NO.
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Old 15-07-2007, 18:00   #4
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This was a topic of an earlier thread. The bow bulbs are more effective on ships/boats that run at a constant speed and the bulbs are immersed to a certain and constant depth. Works grreat on commercial ships but not much use on a sailboat.
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Old 15-07-2007, 18:57   #5
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Quote:
Originally Posted by Steve Rust
This was a topic of an earlier thread. The bow bulbs are more effective on ships/boats that run at a constant speed and the bulbs are immersed to a certain and constant depth. Works grreat on commercial ships but not much use on a sailboat.
I guess I should have done a search.
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Old 19-07-2007, 16:37   #6
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I'm surprised this has been tried so often on multihulls, but I've never seen it tried on a sailing monohull. I would have thought it would work much better on a mono - their potemtial speed range is much smaller given that they essentially can't exceed hull speed.
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Old 19-07-2007, 16:55   #7
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Quote:
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I'm surprised this has been tried so often on multihulls, but I've never seen it tried on a sailing monohull. I would have thought it would work much better on a mono - their potemtial speed range is much smaller given that they essentially can't exceed hull speed.
You've stuck it in, now who's going to twist

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Old 22-07-2007, 03:19   #8
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bow bulbs would also help resist pitching due to increased buoyancy forward, having a damping effect , but would they slow down the hulls because of increased drag ???
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Old 22-07-2007, 04:23   #9
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Crowthers design notes have some info on bulb bows in the pic.

I have sailed on Crowther cat's with bulb's and they were great, but in all fairness, did not sail the same design without bulb's to get a fair comparison.

Dave
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Old 25-07-2007, 17:52   #10
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Quote:
Originally Posted by cat man do
Crowthers design notes have some info on bulb bows in the pic.

I have sailed on Crowther cat's with bulb's and they were great, but in all fairness, did not sail the same design without bulb's to get a fair comparison.

Dave
Thanks for that.
I wonder if it is just that the looks would be a turn-off, visually speaking.
The way people are it would not surprise me to find that bulbs would be better but not accepted because of the way they look.

The first paragraph is pretty cool too.

I tried to google to find it but could not.

Dang............
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Old 25-07-2007, 19:59   #11
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Here is a link to the whole article if that's what you were after

LOCK CROWTHER DESIGN NOTES AS PROMISED

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Old 25-07-2007, 20:16   #12
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Quote:
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Here is a link to the whole article if that's what you were after

LOCK CROWTHER DESIGN NOTES AS PROMISED

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Yes thank you.

I can't copy them though.
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Old 25-07-2007, 20:27   #13
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bulbs have been tried on monohulls there is one here in NZ that was built in Germany 30 + years ago, whether it made any difference??
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Old 25-07-2007, 21:35   #14
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Yes thank you.

I can't copy them though.
Treat it like a picture.

Left click, save picture as.

Dave
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Old 26-07-2007, 15:01   #15
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Treat it like a picture.

Left click, save picture as.

Dave
That I can do.
Just can't cut and paste part of it to a friend.

No biggie..........I will send him the link.

Thanks.
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