Reply
 
Thread Tools Search this Thread
 
Old 05 October 2004, 11:39   #1
Member
 
Country: UK - England
Boat name: SOLD
Length: under 3m
Join Date: Jun 2004
Posts: 794
Stepped hulls

I am looking for a new rib and i have seen a few with stepperd hulls they are more exspence than normal but could some one tell me what you would gain by having a stepped hull.
80% of my ribing is done in or very near to the solent and we do a fair amount of wake boarding in langstone harbour
Roy
__________________

__________________
Roy Smith is offline   Reply With Quote
Old 05 October 2004, 13:04   #2
Member
 
Country: UK - England
Town: London
Make: Larson
Length: 7m +
Engine: Volvo D4 260hp DP
Join Date: Oct 2003
Posts: 275
Roy, Don't know about RIB's but I have the Larson's Duo-Delta Conic hull that's designed to give quicker hole-shots with less bow rise, this together with the stainless duo props I have give fantastic results, including better speed, fuel economy (as it rides partly on a pocket of air) and great handling. I do believe that Mark Pascoe builds stepped hull boats, as I got my trailer from the person who supplies him, they require a slightly different set up with the stepped hull.
__________________

__________________
peteb is offline   Reply With Quote
Old 05 October 2004, 13:06   #3
Member
 
qcamel's Avatar
 
Country: UK - England
Town: Newcastle upon Tyne
Boat name: Happy Hours
Make: Scorpion
Length: 8m +
Engine: 300 Verado
MMSI: 235040122
Join Date: Aug 2004
Posts: 476
I have a stepped hull on my RIB and my understanding is that the hull shape encourages the stern to sit higher in the water when running and also to get onto the plane quicker.

However I bought this boat as seen and so did not spec the hull, I wonder just how much differance it really makes. I do know that the turbulance confuses my depth gauge and so I lose its reading above about 15 knots.

Gets some attention when on the trailer, looks a little odd most people think.
__________________
Ollie
qcamel is offline   Reply With Quote
Old 05 October 2004, 13:22   #4
Member
 
Country: UK - England
Town: I.O.W/Bristol
Boat name: HotShot
Make: shakey
Length: 5m +
Engine: 70hp Tohatsu
Join Date: Jul 2003
Posts: 1,543
Roy,

The man you should speak to I think is Adam Younger on this Forum. His company is K4+ (www.K4plus.com) and they have recently developed a stepped hull RIB of 6.5m. It has tapered steps to aid cornering stability at high speeds (which is a problem with normal stepped hulls I believe) but still keeping the advantages of steps in a straight line. I think this is all right, someone may correct me!

Adam, If you read this how did you do in Cardiff then?! I would love to take you up on the offer of that ride in the RIB sometime

Cheers

Tim
__________________
slimtim is offline   Reply With Quote
Old 05 October 2004, 13:54   #5
Seb
Member
 
Country: UK - Wales
Make: Humber
Length: 5m +
Engine: E-tec 50
Join Date: Jul 2003
Posts: 237
My understanding of stepped hulls, although limited, is that they basically help reduce the wetted area of the hull, thus reducing drag which ultimately leads to greater performance.

Also, if you can imagine driving into a head sea with a stepped hull, each wave that passes along the keel will cause the boat to alter its angle in the water and will allow higher speeds to be maintained without the need to drive 'on the throttle' to such a degree.

i.e. As each individual step in the hull passes over the crest of a wave, the boats bow will drop by the depth of the step. If this is then repeated over numerous steps, the bow will gradually drop as the wave passes beneath meaning that easing off the throttle may not be required which in racing, is obviously beneficial.

My be wrong but it kinda makes sense if you can understand my explanation!!
__________________
Seb is offline   Reply With Quote
Old 05 October 2004, 16:00   #6
Member
 
Country: UK - England
Boat name: SOLD
Length: under 3m
Join Date: Jun 2004
Posts: 794
So if i am not racing it wont realy help me ?
Thanks to every body for replying.
Roy
__________________
Roy Smith is offline   Reply With Quote
Old 05 October 2004, 16:37   #7
Member
 
Country: UK - England
Town: London
Make: Larson
Length: 7m +
Engine: Volvo D4 260hp DP
Join Date: Oct 2003
Posts: 275
Your right Roy, it's not the type of hull for the pipe, dressing gown and slipper man
__________________
peteb is offline   Reply With Quote
Old 07 October 2004, 06:15   #8
Member
 
Richard B's Avatar
 
Country: UK - England
Town: Devon
Boat name: White Ice
Make: Ranieri
Length: 5m +
Engine: Suzuki 115hp
Join Date: Jul 2002
Posts: 5,015
This might be of interest: http://www.ocke.se/motorboats/technology/index.html
Richard B is offline   Reply With Quote
Old 07 October 2004, 06:20   #9
Member
 
Country: UK - Wales
Town: swansea
Boat name: Too Blue
Make: BLANK
Length: 8m +
Engine: Suzuki DT225
Join Date: Mar 2004
Posts: 12,791
Read an article in a Rib mag where they said that an inexperienced driver could have big probs with a stepped hull - apparently they can suddenly skid out of turns or even hook and chuck people out.
__________________
codprawn is offline   Reply With Quote
Old 07 October 2004, 06:31   #10
Member
 
Country: UK - England
Town: London
Make: Larson
Length: 7m +
Engine: Volvo D4 260hp DP
Join Date: Oct 2003
Posts: 275
I'm still alive (Lucky I bought those mini flares to keep in my jacket though )

Joking apart, my hull is very responsive and I have never been almost thrown out, a RIB may be a different matter.
__________________

__________________
peteb 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 04:37.


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