Aluminium RIB

Adam Younger · 19 March 2004, 16:51

My company, K4+, has been very active on the RIB design scene for a number of years. However we have just finished the design of our first Aluminium craft. She is being built on the Isle of Wight and the builders are making an excellent job.
She is 7.5 metres with a twin step arrangement. It is a hull system we have developed over some time and the steps are tapered running into a double chine.

Adam Younger · 19 March 2004, 16:52

another shot - actually the hull plating is now mostly finished.

Richard B · 19 March 2004, 16:56

Looks interesting, Adam. Will you be racing that RIB?

Adam Younger · 19 March 2004, 17:02

No - unfortunately not - it's being build as a demonstrator by a yard to show both the design and their quality of their workmanship.

However I will hopefully be doing a few events in a 6.5M GRP RIB that we have gone into production of. Does not really fit into the classes now as it is too small for Formula two - but should be fun for some basic races. Also hope to do some cruises during the year.

Also racing an offshore catamaran in the two litre class - so it's going to be a busy and exciting year!

tim griffin · 19 March 2004, 18:17

Hi Adam
nice lines to your ali rib, you do sound as though you are going
to be full on this year, who is doing the work for you over here
regards
tim
www.griffmarineservices.co.uk

Pitkis · 20 March 2004, 15:51

Have you calculated, how much more weight your boat gather with aluminium hull compared to GRP?

Adam Younger · 20 March 2004, 19:36

The boat is being built by A & M Fabrications on the Isle of Wight and will be used as their own demo boat. Really to show off what can be done with Aluminium and the quality of their workmanship - which I must say is first class. Hopefully we will look into other designs being built as well.

As to weight it is quite possible to build a very lightweight boat with Aluminium - so it comes down to what degree of sophistication you are building with regards to GRP / Composites.

With this boat we have not gone super light weight and have kept the plating to a pretty durable thickness. At the same time this will not give us any weight penalty over a GRP structure. The hull was also designed with this very much in mind.

jwalker · 20 March 2004, 21:33

Adam, is the hull a warped flat plate or are you managing to build a composite curve?

Adam Younger · 22 March 2004, 19:24

Hi JW

Yes there is camber in the aft sections which works very well in stiffening up relatively thin hull skins (i.e. Aluminium or non-cored GRP) and providing good initial lift.

The amount of camber is actually reduced in the forward sections so that the sheet can be developed around the bow without the need for forming the material in two directions. However as the sheet is developed conically a section at 90 degrees (i.e. transverse frame) will actually appear to have camber in that plane.

Will get some photos soon showing the forward plating on the boat.

Adam

jwalker · 22 March 2004, 20:06

Adam, in this situation, by camber you mean....?

Photos would be interesting. How would you like to crouch down at the bow, at various angles, and take a few shots so we can see the cross section at the hull?

Adam Younger · 23 March 2004, 07:18

Good Morning JW

Camber just means putting some curvature into the deadrise angle - rather than going straight line. Various camber ratio's are used depending on what you are trying to achieve etc.

The amount of curvature will be much more at one end of the curve than the other. Much along the lines of many decks where you often hear of deck camber - so that the deck is flat in the centre but then drops away towards the deck edge.

Will probably be at the builders of the Ali RIB next week so will try to get some shots of it then.

Adam

jwalker · 23 March 2004, 12:51

Thanks Adam, that's what I guessed you meant.

I don't quite understand the description of the plating being part of the surface development of a cone. I do understand surface developments, conic sections etc. How'd you like to draw a wee pic. and post it? Ta.

Adam Younger · 23 March 2004, 17:07

Let me see what I can put together for you.

Cheers
Adam

Adam Younger · 13 April 2004, 09:54

latest shot - actually taken prior to Easter. Progress has slowed a bit as paying jobs have taken over at the builders.

Should have photo's with hull plating in place soon.

jwalker · 13 April 2004, 10:28

Good. It's beginning to look the part.

Adam Younger · 19 April 2004, 08:46

latest photo

Actually looking to carry out other projects with my company designing and with this builder in Aluminium. May not be stepped hulled RIB's - but it is a pretty good starting point to show level of workmanship.

bogib · 19 April 2004, 22:10

Adam fantastic looking how your ali-rib comes along looking forward seeing it on water and how she will perform on water.
Keep going with the project.....
___________
Bogi

Adam Younger · 21 April 2004, 08:11

Hi Bogi

Nice easy (relatively) one for me this time - I'm just the designer! The boat is being built by Frank McLean for himself and to promote his own business.

Looking forward to seeing it on the water too. Although obviously a performance hull it is still intended to be a good all round boat and is not full on race boat lines.

Adam

PS still working on those F3 prices - but recently we have changed laminators and tube manufacturers - so a few things still to consider.

tim griffin · 21 April 2004, 08:12

give us a go ! it looks great
tim
www.griffmarineservices.co.uk

slimtim · 04 June 2005, 20:50

Adam,

Do you have any up to date pics of this RIB? Is she afloat, if so how does she compare to your Aramid demo boat?

Hope the new opti is running well.

Cheers

Tim