My Carbon Rib Project

GBR1 · 16 October 2009, 12:20

So I am finally finishing off a carbon rib project. Its been a few years in the making, it almost got completed a few years ago but lack of funds brought the project to a halt. The idea was to make a 7m rib as light a possible but still being functional and robust. Adrian Thompson has designed the hull, the rib has been built out of carbon with a high density impact resistant foam. Half the reason for funds drawing short is the fact that no expense was speared on the construction and materials!

So the long and the short of it soon to be finished is a 7m rib with a 100HP Yamaha 2010 engine weighing in at 540kg. The handy thing about this is also that on the road trailer the all up weight should be less than 750KG!

There has been one other hull drawn from the mould, this had a diesel inboard added. The boat is amazing in heavy seas, better than Tornado ribs I have used in equivalent conditions.

Just thought I would share these pics with you, finished pics in a month or so!

chewy · 16 October 2009, 19:59

How much faster or more efficient will it be than a normal GRP RIB?
Should be strong any way and looks good.

GBR1 · 16 October 2009, 20:48

Quote:

Originally Posted by chewy

How much faster or more efficient will it be than a normal GRP RIB?
Should be strong any way and looks good.

The main advantage is because its almost half the weight of a normal GRP Rib I can use a much smaller engine. Most 7m ribs are using 150HP+ where I will be able to get away with a 100HP, there is also another gain in weight between the engines. Time will tell but I hope she will still make 40knots with the 100!

PeterR · 16 October 2009, 21:01

Sounds like a great combination size with good fuel consumption ,its what most are looking for but without the expense.Will be watching with great interest

andyxs · 16 October 2009, 22:13

Hi that looks like a really good project what did it cost in the end?, could i ask you a couple/load of questions as me and a mate of mine were contemplating building ourselvs some carbon ribs when we get some money lol but our experience is mostly in yacht building/messing around, what lay up did you use to create the strength needed? and what sort of foam did you use? did you use foam to make the deck or plywood? did you use wood in any other areas, how much carbon did you go thru in the end (that stuff is expensive lol) and did you cook it? breath lol

Cookee · 17 October 2009, 08:55

I am interested to see how it handles in rough conditions - if it has the same underwater profile of a regular GRP boat it will have too much lift for its weight and end up in the air too often - IMHO.

We modified the hull on our race boat and did just that - had too much lift and we spent too much time in the air, we then removed part of the modifications and solved the problem - less air more drive.

Jizm · 17 October 2009, 10:39

Looks good, loking forward to the next installment/sea trial.

GBR1 · 17 October 2009, 17:28

Quote:

Originally Posted by Cookee

I am interested to see how it handles in rough conditions - if it has the same underwater profile of a regular GRP boat it will have too much lift for its weight and end up in the air too often - IMHO.

The hull has been designed from the outset with the final weight in mind, so it own mould was built! There is one other hull out of the mould, this does have a diesel inboard but it handles exceptional well, as for mine time will tell!!

Channel Ribs · 17 October 2009, 20:16

Quote:

Originally Posted by GBR1

So the long and the short of it soon to be finished is a 7m rib with a 100HP Yamaha 2010 engine weighing in at 540kg.

Sounds like a fine candidate for the round Alderney (on 6Ltrs of fuel) race!

Bigmuz7 · 18 October 2009, 23:31

Quote:

Originally Posted by Cookee

I am interested to see how it handles in rough conditions - if it has the same underwater profile of a regular GRP boat it will have too much lift for its weight and end up in the air too often - IMHO.

On the money

Weight has its advantages

The Grocer · 19 October 2009, 00:49

Quote:

Originally Posted by Bigmuz7

Weight has its advantages

Must try that one at the next "well man" session...

...I'm not overweight. I'm undertall.

To the bilges...

Knot Yet · 19 October 2009, 06:51

Bigmuz7 · 19 October 2009, 07:42

Quote:

Originally Posted by The Grocer

To the bilges...

Nooooo .... not yet .....

I forgot how careful you need to be around here .. 360 degree vision for reply post 'sniper fire'

.. my qualifying statement should have had the words "In the right places" not forgetting "IMVVHO"after it ..

GBR1 · 19 October 2009, 20:53

Quote:

Originally Posted by Bigmuz7

On the money

Weight has its advantages

In what way??

Bigmuz7 · 19 October 2009, 23:00

Quote:

Originally Posted by GBR1

In what way??

Firstly I dont mean to demean you project in any way let me get that straight

.. we need all these advances in tech to move forward.

I simply made the point in agreement with Cookie that, in the last 10 years Ive owned and operated 4 different hull configurations, and have found that weight configuration is vitally important (together with the hull design) In that ,.. even if there are shortcomings in the fit out of the boat .. where all the stuff is put .. from fuel tanks to consoles, it has a massive effect on the boats performance, with respect to its hull form, and I've sucessfully ballasted various designs to correct the various fit out problems. This has been a frustrating learning curve , and I'd like one day to be able to buy a boat that doesnt have me lifting drums of water on board to make it run right

.. My last boat for example was a quite shallow V rib .. but I stuck 2 anchors and chain in the bow locker and was one of the best riding hulls Ive had .. aided by the fact the console was set aft also

Depends ofcouse what sea you want to run in .. but I'll be interested to see how your project goes

simmons0 · 20 October 2009, 00:08

But the lighter the boat is in the first place the less ballast/trim you'd need to correct any issues.

Cookee's point was an interesting one, i'd never thought about that, but in this case with a hull designed from the start to be that light it can only be a good thing!
Harry

Bigmuz7 · 20 October 2009, 07:28

Quote:

Originally Posted by simmons0

But the lighter the boat is in the first place the less ballast/trim you'd need to correct any issues.

Not neccessarily .. because when you hit a wave at speed you need a balance of not too much lift, and not too much bite as both will impede your progress .

GBR1 · 20 October 2009, 07:30

Quote:

Originally Posted by Bigmuz7

Firstly I dont mean to demean you project in any way let me get that straight

..

No don't worry, it a learning curve for all! I understand what you are saying, but I think that the problem with mass produced ribs is that they are built to a degree with budget in mind, they have to be as the company's have to make a profit that's life.

If you have you own project you work out you bear hull weight, engine weight and then you can start adding bits, so my rib we started with me at 80KG plus fuel etc etc worked out the COG and then added them in the correct place for the balance of the boat. This gave us the console position, and fuel tank position etc, so then under the decks we said the fuel need to go here so longitudinals and bulkheads here etc. Hopefully giving you a balanced boat..

Of course this happens with the big manufactures but when you hear of them making 2 different length hulls out of the same mould you have to wonder how much thought went into the dynamics of the boat and not profit margins! So now you have a 7m rib out of an 8m rib mould and then people wonder why you have to add weight to keep the bow down from too much lift as nobody wants to drive 1meter from the bow!

As said time will tell if mine is any good!

chewy · 20 October 2009, 08:24

Atlantic 85's are carbon fibre and the RNLI seem happy enough with them, they do weight about 1.8 tonnes though!

9D280 · 20 October 2009, 16:29

This is sounding a bit like a modern version of my museum. Mine evolved into what is now the O-Pro. Difference is mine weighs in at 420 Kg fully fuelled with a Merc 60 on the back. Doing a quick subtraction puts the hull at around the 280Kg mark. as opposed to the O-Pro which weighs in at 350Kg. Granted the extra weight means the transom on the new hull will take 170Kg & 90 Hp as opposed to my 110/60, but I do wonder how much of the extra HP will be used moving the extra weight around.......

I'd love to do a back to back run with a modern equivalent, as I'm really curious as to how the heavier setup with more HP handles in comparison.

As for the mass production thing, how many of us could still afford to buy a rib if they didn't make those compromises? Same goes for multiple horsepowers out the same engine block...