Reply
 
Thread Tools Search this Thread
 
Old 25 September 2006, 13:13   #11
Member
 
Country: UK - England
Make: Southrib
Length: 9m +
Join Date: Jul 2006
Posts: 10
Quote:
Originally Posted by Petrov
Nice looking boat, what Hamilton jet are you using is it the 274 or 292.
Why i am asking is because speed of 50 knots is very fast for a jet, speeds over 47-48 knots is really hard to reach, we are in a jet project and been calculating some speed but they dont reach 50 knots.
Do you have the weight of the boat?
Are we talking 50 knots or 50 mph?
Thanks chap,
I would have to lookup the Jet Model, but the impellor has had some work so it's not what you would call "standard". The trick to this rib is that every aspect of it has been tuned for speed. It will do 50kts (just) as-is but its my opion that the speed will increase a little ( 2-3kts) when the lump loosens up (its still under 50hours old and the turbo is a little tight).
It wieghs in "hull-wet" at about 2500Kilos as you see it in the pictures and most of that saving is in the construction.
A race version could easily save 200-250kilos by ditching the Bimini, most of the electronics and console. Also a petrol lump would shave yet more. However, the idea was to design a boat that was everyday useable, had good manners, resonable seakeeping/stabilty/manouverability, very high speed and still had the basics to make a day floating about on the water a pleasure.
i like to think that they were'nt too far off the mark. There are improvemnts to come on the next one as lesson were learned but for the first build of new design, it looks very good to me.
__________________

__________________
damoace is offline   Reply With Quote
Old 25 September 2006, 13:20   #12
pop
Member
 
Country: New Zealand
Town: Paihia
Make: Scorpion
Length: 8m +
Engine: indoard yam 420 sti
Join Date: Feb 2006
Posts: 383
thanks i hope it all goes well

give us an idea near the scorpion price or the rib tec?
__________________

__________________
pop is offline   Reply With Quote
Old 25 September 2006, 13:25   #13
Member
 
Country: UK - England
Make: Southrib
Length: 9m +
Join Date: Jul 2006
Posts: 10
Cheers!

Its over 100grand if that answers your question...
__________________
damoace is offline   Reply With Quote
Old 25 September 2006, 13:26   #14
pop
Member
 
Country: New Zealand
Town: Paihia
Make: Scorpion
Length: 8m +
Engine: indoard yam 420 sti
Join Date: Feb 2006
Posts: 383
perfect
__________________
pop is offline   Reply With Quote
Old 25 September 2006, 14:04   #15
Member
 
Country: Sweden
Town: Stockholm
Boat name: Osprey & Ring
Make: Osprey & Ring
Length: 9m +
Engine: Plenty
Join Date: Mar 2003
Posts: 860
Quote:
Originally Posted by damoace
Thanks chap,
I would have to lookup the Jet Model, but the impellor has had some work so it's not what you would call "standard". The trick to this rib is that every aspect of it has been tuned for speed. It will do 50kts (just) as-is but its my opion that the speed will increase a little ( 2-3kts) when the lump loosens up (its still under 50hours old and the turbo is a little tight).
It wieghs in "hull-wet" at about 2500Kilos as you see it in the pictures and most of that saving is in the construction.
A race version could easily save 200-250kilos by ditching the Bimini, most of the electronics and console. Also a petrol lump would shave yet more. However, the idea was to design a boat that was everyday useable, had good manners, resonable seakeeping/stabilty/manouverability, very high speed and still had the basics to make a day floating about on the water a pleasure.
i like to think that they were'nt too far off the mark. There are improvemnts to come on the next one as lesson were learned but for the first build of new design, it looks very good to me.
Thanks for info, i had a meeting with Hamilton (New Zeeland Hamilton) the other day and they told me you never can reach more topspeed with other impellors but more topspeed when fully loaded.
Will be interesting to se what speed will be in the end, we will use a Caterpillar C9 (575hp) with the HJ322.
Unbelivable to hear the figures, in a HJ322 it passes 800 liters of water/s wich is 48,000 liters in a minute
Boat is 10,5 and we got a topspeed of 48 knots at 3,500kg and 42 knots at fully load 5,000kg, will se if figures is correct when its finished.
__________________
www.grandrib.se
Petrov is offline   Reply With Quote
Old 25 September 2006, 18:14   #16
Member
 
Country: UK - England
Make: Southrib
Length: 9m +
Join Date: Jul 2006
Posts: 10
Quote:
Originally Posted by Petrov
Thanks for info, i had a meeting with Hamilton (New Zeeland Hamilton) the other day and they told me you never can reach more topspeed with other impellors but more topspeed when fully loaded.
Will be interesting to se what speed will be in the end, we will use a Caterpillar C9 (575hp) with the HJ322.
Unbelivable to hear the figures, in a HJ322 it passes 800 liters of water/s wich is 48,000 liters in a minute
Boat is 10,5 and we got a topspeed of 48 knots at 3,500kg and 42 knots at fully load 5,000kg, will se if figures is correct when its finished.
Hi Petrov,
I suspect that the main difference is in the wieght and length. you are 10.5mtrs and 3500Kgs. We are 9.5 mtrs and 2500kgs. i know that length=speed but that still makes your rib a ton heavier. I Understand about the "loaded speed" issue. My understanding was more along the lines of maiking the water passage through the jet as "low drag" as possible. Low friction equals more jetspeed for the same revs/impellor.To that end the hull right in front of the jet intake is very flat and smooth to make sure that the flow into the jet is as straight and dense as possible. All that said, I'm not the jet expert but the general theory made sense when it was explained to me. That said, Hamilton should know for sure as they are the experts on Waterjet drives.
I'm everyday I spend with the boat is a day i learn what I thought is wrong. But jets will do that to you. They are totally different beasties!

Good luck with yours Chappie, it sounds like a riot!
__________________
damoace is offline   Reply With Quote
Old 25 September 2006, 21:53   #17
Member
 
Country: UK - Wales
Town: swansea
Boat name: Too Blue
Make: BLANK
Length: 8m +
Engine: Suzuki DT225
Join Date: Mar 2004
Posts: 12,791
Remember jet skis can be pretty quick.....
__________________
codprawn is offline   Reply With Quote
Old 26 September 2006, 02:47   #18
Member
 
Country: Sweden
Town: Stockholm
Boat name: Osprey & Ring
Make: Osprey & Ring
Length: 9m +
Engine: Plenty
Join Date: Mar 2003
Posts: 860
Hmmm, but i still have more hp per kg and stil dont get the 50 knots.
I talked to Hamilton about the plate infront of the jet, how it suppose to look and what angl it will have.
Wil se when boat is finished, thanks for the input
__________________
www.grandrib.se
Petrov is offline   Reply With Quote
Old 26 September 2006, 05:45   #19
Member
 
Country: UK - England
Make: Southrib
Length: 9m +
Join Date: Jul 2006
Posts: 10
look forward to it..
__________________
damoace is offline   Reply With Quote
Old 10 October 2006, 06:55   #20
Member
 
Country: UK - England
Town: Cowes
Boat name: NIPPER
Make: South 9m
Length: 9m +
Engine: Inboard Diesel
Join Date: Oct 2006
Posts: 1
South RIB 9m

Hi all and thanks for all your comments on our 1st of class RIB. To clarify earlier posts, the boat weighs 2,500kg's mainly due to the use of composite framing and deck structure. The hull remains Lloyds approved commercial conventional lay up. There is no plywood on the vessel, so no troubles with soaking up water and in fact you cannot even trap water in a compartment. In line with modern offshore lifeboats a central bilge sump is fitted trunked through the vessel to twin automatic pumps and a manual pump. we have integrated the waterjet, a Hamilton 274 into the hull design and it is fitted uniquely to offer a large after planing pad rather than recessed as is the norn with jet boats. The engine is a Yanmar 6LY-STE 440hp without gearbox and the boat always achieves 47 knots without any hassle and accelerates to that speed in an instant. With respect to heavy weather, we have had it out in more than 1m and the boat is very comfortable an untroubled in fact 47 knots in 0.3-0.5 is easy. In all of my experience I have never been on such a comfortable, driveable RIB, whick fills the coxswain with confidence and enthusiasm. It is a remarkable little boat. We are aiming to sell in the commercial sector only but if a leisure wanted one, let me know. They are a bespoke build so specifications i.e single, twin, jet, outdrive, wheelhouse, open, bimini etc. can all be accommodated. Ring Ben Colman, South Boats SP Ltd., Medina Shipyard, Cowes, Isle of Wight, PO31 7PG 01983 280030 or ben.colman@btconnect.com. Thanks all.
__________________

__________________
bensouth is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 18:53.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.