An early design of my Sprayskirt had much more material up front and definitely effected tacking in high winds and recovering from submarineing... but it DID LOOK GOOD!
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| A very different Bow design from Norway http://www.hobie.com/au/en/forums/viewtopic.php?f=71&t=37683 |
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| Author: | Trinomite [ Thu Aug 18, 2011 5:26 am ] |
| Post subject: | A very different Bow design from Norway |
http://www.youtube.com/watch?v=GJsogw9f ... re=related http://www.stowmasters.com/xbow.htm Compare the ship having a conventional Bow with the Ship using the new "X-Bow' design in the above video. Hmmm, the increased buoyancy in that ship certainly keeps the ship from 'nosediving' Note to Hobie designers: A much smaller variation on Islands combined with built in bow foils might make quite a huge difference to keep the bow from diving at high speed. Regards Trinomite |
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| Author: | Salty Dawg [ Thu Aug 18, 2011 11:14 am ] |
| Post subject: | Re: A very different Bow design from Norway |
That's an interesting concept. I'm also wondering about their use of forward and aft ballast tanks to trim the pitch axis of the bow. |
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| Author: | TIDALWAVE [ Thu Aug 18, 2011 5:01 pm ] |
| Post subject: | 2 1/2 times bow height |
It appears that the new bow extends about 2 1/2 to 3 times higher than the older 'bulb' bow. I am not sure what the windage would be if my TI's bow were to extend a couple of feet out of the water. I have enough trouble trying to tack it in a strong blow when by myself. My spray skirt seems to be an optimal compromise...keeps the spray off with minimal side wind resistance. |
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| Author: | KayakingBob [ Thu Aug 18, 2011 8:09 pm ] |
| Post subject: | Re: A very different Bow design from Norway |
An early design of my Sprayskirt had much more material up front and definitely effected tacking in high winds and recovering from submarineing... but it DID LOOK GOOD!
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| Author: | Trinomite [ Thu Aug 18, 2011 9:24 pm ] |
| Post subject: | Re: A very different Bow design from Norway |
Hey Guys This post is pure theory. Yet if you look at almost the same 2 ships in the vid, the one with the X-bow seems to have an easier time. Again these are displacement vessels designed to supply North Sea Oil/Nat Gas Rigs not planing vessels. Yet if you read the write up, they do mention an increase in speed and better fuel economy. That would mean this new design is more efficient in heavy seas (without the need for a bulb nose). (yup the bow houses the entire crew and tons of pipes to play with the ballast tanks (I would think) I think maybe I should have reworded it better to the Hobie Design Team: If we were to put more mass (more, not a total redisplacement of the vessel) the advantage might be less submarining. .....plus the addition of a hard foil to get bow lift for better planing ability.....rec  Just a thought Be well Trinomite |
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| Author: | Trinomite [ Thu Aug 18, 2011 9:43 pm ] |
| Post subject: | Re: A very different Bow design from Norway |
Salty Dawg wrote: That's an interesting concept. I'm also wondering about their use of forward and aft ballast tanks to trim the pitch axis of the bow. Good point, Salty. If you look at the vid when the camera turns to the X-bow, you can see intake ports on each side of the bow spitting water, so yah, it is prolly computer controlled pumps to aid in fore, aft hull ballast to shift weight as needed. (remember this is a copy written (patented) design and details appear to be a bit sketchy. It is also run with 4 power pods, which is where the bulb nose looses it`s efficiency. It seems the balance was so perfect that there is also the chance they are using port starboard ballast tanks to keep this boat tracking exactly into the wind (at that angle, the wind and wave force is split in 2 by the bow, thus helping to equalize the vessel.) Thanks for reading Guys, theory, just theory Trinomite |
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| Author: | Trinomite [ Thu Aug 18, 2011 10:08 pm ] |
| Post subject: | Re: A very different Bow design from Norway |
Here`s another thought... I don`t know if you guys have ever been on a deep sea ship or a ferry but that pitching motion in that vid reminded me of when I took the ferry back from The Queen Charlotte Islands back to mainland Canada (early 80`s): When a ship does a nosedive like that, it is like a BOOM!! that sends vibrations into every corner of the ship. The Ferry I was on (for 8 hours) had one of those atypical trad bows. This vessel also had the `misfortune`to have the restaurant on the second highest deck on the ship...... Bad, Bad Idea. (I have never seen so many passengers turn `green`when this ship started to pile through the Hecate Straights (shallow waters, unprotected from the current if the wind is strong and opposing)..and no stabilizers. What actually concerned me more at that time was the concept of taking a paper clip and twisting it back and forth (repeat, thousands of times until the welds and the metal fatigue start to get the better of the vessel) Happy Days Trinomite |
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