Reply
 
Thread Tools Search this Thread
 
Old 22 October 2014, 14:58   #1
Member
 
Country: Other
Town: VALENCIA
Boat name: Madueño
Make: Zodiac
Length: 7m +
Engine: Suzuki df250
Join Date: Apr 2006
Posts: 87
Overpowered Rib

This 8m Astec rib with Yamaha 350V8 seems a bit over powered, maybe 250 HP would have been more than enough, especially considering that almost wears nothing on board...



Although maybe it is to catch the bad guys if they escape, but rather it is a vessel for use by divers
__________________
medlineIII is offline   Reply With Quote
Old 22 October 2014, 15:13   #2
Member
 
Nick Hearne's Avatar
 
Country: UK - England
Town: Bucks
Boat name: Blue & Ding Dong
Make: Ribeye,SR4 & Bombard
Length: 6m +
Engine: 115,50 & 15Hp Yams
Join Date: Feb 2004
Posts: 3,252
Quote:
Originally Posted by medlineIII View Post
This 8m Astec rib with Yamaha 350V8 seems a bit over powered, maybe 250 HP would have been more than enough, especially considering that almost wears nothing on board...



Although maybe it is to catch the bad guys if they escape, but rather it is a vessel for use by divers
Don't know about overpowered, but it looks like it blew the budget as nothing left in the kitty to fit it out!

All looks very tame to me!
__________________
Member of the Ribeye supporters club!!!
Member of Bombard 380 Aerotec club
Member of SR4 club
Nick Hearne is offline   Reply With Quote
Old 22 October 2014, 15:23   #3
Member
 
Trimix's Avatar
 
Country: UK - England
Boat name: Hysucat
Make: Hysucat
Length: 8m +
Engine: Twin Suzuki 175's
MMSI: 235102645
Join Date: Jun 2013
Posts: 861
RIBase
What happens if you over power a RIB, doesn't it just go faster
__________________
Trimix is offline   Reply With Quote
Old 22 October 2014, 17:38   #4
Member
 
Maximus's Avatar
 
Country: UK - England
Town: Wild West
Boat name: No Boat
Make: No Boat
Length: under 3m
Join Date: Jan 2008
Posts: 5,305
Send a message via AIM to Maximus
Quote:
Originally Posted by Nick Hearne View Post
Don't know about overpowered, but it looks like it blew the budget as nothing left in the kitty to fit it out!

All looks very tame to me!
Power looks fine to me!....Definatly needs some weight forward to make the most of it though
__________________
A clever Man learns by his mistakes..
A Wise Man learns by other people's!

The Road to HELL ..is Paved with "Good inventions!"
Maximus is offline   Reply With Quote
Old 22 October 2014, 17:44   #5
RIBnet admin team
 
Poly's Avatar
 
Country: UK - Scotland
Boat name: imposter
Make: FunYak
Length: 3m +
Engine: Tohatsu 30HP
MMSI: 235089819
Join Date: Sep 2005
Posts: 11,622
Quote:
Originally Posted by Trimix View Post
What happens if you over power a RIB, doesn't it just go faster
or it starts to chine walk and flips the crew who appear to have no seats out!
__________________
Poly is offline   Reply With Quote
Old 22 October 2014, 18:33   #6
Member
 
Country: UK - England
Town: Hamble
Length: 9m +
Join Date: Dec 2002
Posts: 2,317
Why would "overpowering" cause it to chine walk?
__________________
It is better to remain silent and be thought a fool, than to speak and remove all doubt!
Dirk Diggler is offline   Reply With Quote
Old 22 October 2014, 18:58   #7
RMS
Member
 
RMS's Avatar
 
Country: UK - England
Town: Pudsey
Boat name: Aquaticus / HATOWIL
Make: Ribquest and Zodiac
Length: 6m +
Engine: Suzuki 140 and 90
Join Date: Dec 2011
Posts: 132
Guardia Civil tend to keep the boats they pull that are shall we say in the "import business" so this could be a a boat that was intended to be run with a bit of weight up front.
__________________
RMS is offline   Reply With Quote
Old 22 October 2014, 19:24   #8
RIBnet supporter
 
bartiny's Avatar
 
Country: UK - England
Town: Accrington
Length: no boat
Join Date: Oct 2012
Posts: 451
2 stroke is best lol

The vids a bit poor but woth the effort

__________________
bartiny is offline   Reply With Quote
Old 22 October 2014, 19:32   #9
RIBnet admin team
 
Poly's Avatar
 
Country: UK - Scotland
Boat name: imposter
Make: FunYak
Length: 3m +
Engine: Tohatsu 30HP
MMSI: 235089819
Join Date: Sep 2005
Posts: 11,622
Quote:
Originally Posted by Dirk Diggler View Post
Why would "overpowering" cause it to chine walk?
I'd have thought that would be obvious to you. Are you suggesting that power is not a significant contributing factor in chine walking?

Which bit of my logic is flawed?

Increased power = faster. Faster = more lift. More lift = less surface area in the water. Less surface area = more likely to imbalance. Imbalance + high speed = chine walk.

The advice always given here to people who experience a chine walk is to back off the throttle. There is other advice about trim, engine height etc to try to prevent it - but the universal message is that to stop it rather than make it less likely: slow down.

Its probably exaggerated on boats which are overpowered because they tend to be badly set up too with heavy engines etc.

Now I'm* not saying 350HP on an 8m boat is overpowered, I was answering the question "What happens if you over power a RIB, doesn't it just go faster".

*although ISO6185 suggests it might be!
__________________
Poly is offline   Reply With Quote
Old 22 October 2014, 19:34   #10
Member
 
Country: UK - England
Town: Gloucestershire
Boat name: Osprey
Make: Osprey Vipermax
Length: 5m +
Engine: E-tec 300 G2
MMSI: TBC
Join Date: Dec 2006
Posts: 4,020
[QUOTE=bartiny;652381]The vids a bit poor but woth the effort QUOTE].... and is an excellent demo of what happens when you overpower a rib !. Chine walks as soon as he opens it up so a complete waste of time
__________________
---------------------------------------------------
Chris Stevens

Born fiddler
Chris is offline   Reply With Quote
Old 22 October 2014, 19:42   #11
RIBnet supporter
 
bartiny's Avatar
 
Country: UK - England
Town: Accrington
Length: no boat
Join Date: Oct 2012
Posts: 451
Quote:
.... and is an excellent demo of what happens when you overpower a rib !. Chine walks as soon as he opens it up so a complete waste of time
Thats why I posted it
__________________
bartiny is offline   Reply With Quote
Old 22 October 2014, 19:43   #12
Member
 
Maximus's Avatar
 
Country: UK - England
Town: Wild West
Boat name: No Boat
Make: No Boat
Length: under 3m
Join Date: Jan 2008
Posts: 5,305
Send a message via AIM to Maximus
Quote:
Originally Posted by Poly View Post
I'd have thought that would be obvious to you. Are you suggesting that power is not a significant contributing factor in chine walking?

Which bit of my logic is flawed?

Increased power = faster. Faster = more lift. More lift = less surface area in the water. Less surface area = more likely to imbalance. Imbalance + high speed = chine walk.
And Chine walking....if you don't Back off...may well lead to the whole Boat "Hooking"....on its Axis..especially in certain sea States.....not much fun I'm reliably informed!!
__________________
A clever Man learns by his mistakes..
A Wise Man learns by other people's!

The Road to HELL ..is Paved with "Good inventions!"
Maximus is offline   Reply With Quote
Old 22 October 2014, 20:13   #13
Member
 
Powerboats's Avatar
 
Country: UK - England
Town: Southampton
Make: ZAR
Length: 9m +
Join Date: Jul 2006
Posts: 141
Can't see any chine walking in the OP's video.

Boat seems to plane early despite being fitted with one of the heaviest outboards on the market and crew and console aft.

Still riding with bow a bit high suggesting capacity for additional weight forward.

Looks like a nice deep-vee forward as well. Totally different boat to the second video.

Not enough evidence to form a negative opinion.

No connection - never heard of them.
__________________
WWW.BOATSMART.CO.UK
RIBs, Tenders, Dinghies and inflatable Kayaks and SUPs in stock at our Swanwick, Hampshire showroom
Powerboats is offline   Reply With Quote
Old 22 October 2014, 20:22   #14
Member
 
Nick Hearne's Avatar
 
Country: UK - England
Town: Bucks
Boat name: Blue & Ding Dong
Make: Ribeye,SR4 & Bombard
Length: 6m +
Engine: 115,50 & 15Hp Yams
Join Date: Feb 2004
Posts: 3,252
Quote:
Originally Posted by bartiny View Post
The vids a bit poor but woth the effort

Ha this reminds me of my SR4 she kicks like a mule
__________________
Member of the Ribeye supporters club!!!
Member of Bombard 380 Aerotec club
Member of SR4 club
Nick Hearne is offline   Reply With Quote
Old 22 October 2014, 20:28   #15
RIBnet supporter
 
bartiny's Avatar
 
Country: UK - England
Town: Accrington
Length: no boat
Join Date: Oct 2012
Posts: 451
Quote:
Originally Posted by Powerboats View Post
Can't see any chine walking in the OP's video.

Boat seems to plane early despite being fitted with one of the heaviest outboards on the market and crew and console aft.

Still riding with bow a bit high suggesting capacity for additional weight forward.

Looks like a nice deep-vee forward as well. Totally different boat to the second video.

Not enough evidence to form a negative opinion.

No connection - never heard of them.
Nobody said it was chine walking, the referance to chine walking is in response to post No. 3
__________________
bartiny is offline   Reply With Quote
Old 22 October 2014, 20:46   #16
Member
 
Powerboats's Avatar
 
Country: UK - England
Town: Southampton
Make: ZAR
Length: 9m +
Join Date: Jul 2006
Posts: 141
Fair enough, but as I read it the suggestion was that the original boat was overpowered, and it was then suggested this would cause chine walking.

My point, and I'm sure what Poly was alluding to as well, is that a poor combination of weight distribution, hull design and power delivery are the true factors that result in any badly performing RIB or powerboat design.
__________________
WWW.BOATSMART.CO.UK
RIBs, Tenders, Dinghies and inflatable Kayaks and SUPs in stock at our Swanwick, Hampshire showroom
Powerboats is offline   Reply With Quote
Old 22 October 2014, 21:27   #17
Member
 
Bigmuz7's Avatar
 
Country: UK - Scotland
Town: Glasgow
Boat name: stramash
Make: Tornado
Length: 5m +
Engine: Etec 90
Join Date: Feb 2006
Posts: 5,090
Quote:
Originally Posted by Poly View Post
or it starts to chine walk and flips the crew who appear to have no seats out!
Quote:
Originally Posted by Dirk Diggler View Post
Why would "overpowering" cause it to chine walk?
Quote:
Originally Posted by Poly View Post
I'd have thought that would be obvious to you. Are you suggesting that power is not a significant contributing factor in chine walking?

Which bit of my logic is flawed?

Increased power = faster. Faster = more lift. More lift = less surface area in the water. Less surface area = more likely to imbalance. Imbalance + high speed = chine walk.

The advice always given here to people who experience a chine walk is to back off the throttle. There is other advice about trim, engine height etc to try to prevent it - but the universal message is that to stop it rather than make it less likely: slow down.

Its probably exaggerated on boats which are overpowered because they tend to be badly set up too with heavy engines etc.

Now I'm* not saying 350HP on an 8m boat is overpowered, I was answering the question "What happens if you over power a RIB, doesn't it just go faster".

*although ISO6185 suggests it might be!
Slap on the arse for you Dirk ... and an experienced member too ohh dear

Im with you Poly
__________________
Bigmuz7 is offline   Reply With Quote
Old 22 October 2014, 22:03   #18
RIBnet Supporter
 
willk's Avatar
 
Country: Ireland
Length: 4m +
Join Date: Feb 2008
Posts: 14,664
Quote:
Originally Posted by Bigmuz7 View Post
Slap on the arse for you Dirk ... and an experienced member too
Mr Wiggler has been an Outstanding Member longer than most...
__________________
I'm sorry, but there IS no Mars Bar.
willk is offline   Reply With Quote
Old 23 October 2014, 12:35   #19
Member
 
Country: UK - England
Town: Hamble
Length: 9m +
Join Date: Dec 2002
Posts: 2,317
Quote:
Originally Posted by willk View Post
Mr Wiggler has been an Outstanding Member longer than most...
That probably goes over the top of the majority of heads.

I'm fully aware of the reasons for chine walking, and "overpowering" can certainly be a cause of it, but it's more common for it to be caused by incorrect set up, slack steering, too higher motor, worn engine mounts, hull defect or a drivers inability to correct the problem with proper throttle control or incorrect steering inputs.

In my limited experience of set up etc, I've found the biggest problem is not over powering, but driver error.
__________________
It is better to remain silent and be thought a fool, than to speak and remove all doubt!
Dirk Diggler is offline   Reply With Quote
Old 23 October 2014, 12:52   #20
Member
 
Country: UK - England
Town: Hamble
Length: 9m +
Join Date: Dec 2002
Posts: 2,317
Quote:
Originally Posted by Poly View Post

*although ISO6185 suggests it might be!
I'm a bit rusty on the current rulings, but I think that wouldn't apply to this particular boat.

I assume you mean iso 6185.62?
__________________
It is better to remain silent and be thought a fool, than to speak and remove all doubt!
Dirk Diggler is offline   Reply With Quote
Reply

Tags
rib

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




All times are GMT. The time now is 03:03.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.