CARSON Interceptor RIBs

[Barry Carson]

Hi John,

Ordinarily, depending on engines fitted, etc. and when static, the loaded waterline would be horizontal and situated approx. just below where the spray rail is marked, positioned roughly 1/2 way up the hull's 'topside' between the bottom of the collar and the chine, but still as near horizontal. That is when fully loaded, slightly lower of course when light.

As you can see there's an appreciable amount of rocker in the keel line as it progresses forward to a tightly curved forefoot. This was drawn to minimize any tripping effect from forward and avoid any bow steer by not having too deep a stem while at the same time leaving sufficient keel grip for good directional stability. As already mentioned, there's also plenty of reserve bouyancy to come into play when needed.

General thinking is that any force potentially generated needs a counter force to maintain equilibrium. I've used similar set up in hundreds of ribs since the early 80s with no adverse effect. Quite the opposite.

[Barry Carson]

PS. Perhaps I should also have pointed out that all Carsons of 5m up are designed with the collar well clear of the water even when fully loaded as in the attached photo of a special forces 9 metre weighing at around 7 tons with sufficient fuel for 1,000 miles range. This photo gives a good idea of where the waterline lies.

[John Kennett]

So more like this?

[Barry Carson]

[QUOTE=Pikey Dave;731292]Barry, if you have a demo boat, it has to be called "Dreadnought" it'd be worth buying one just in order to use the name😄 All the best with the project.


Thanks PD. Good name choice.

And we hope to keep the costs considerably below the originals!

[Barry Carson]

Originally Posted by John Kennett

So more like this?

Attachment 116377

As good as!

[John Kennett]

Thanks. I hope we'll get to see one in action before too long. Some side by side comparisons should be very interesting!

[Barry Carson]

First boat out should be on the water before too long so watch this space. And we have the original Carson 900 model as in the photo posted still available together with lots of data on this model to compare with.

[macandrc]

Here are some more shots after last week, safe to say that after a solid week of filling and fairing the plug were glad to have the majority of the fairing behind us, we finished the week by getting the plug sealed in readiness for the application of the Durabuild primer and final prep of the plug this coming week.

Following on we will then be laying up the mould and all its external structure as well as building the large standard console/cabin.

Everyone involved is really pleased with progress and how the plug is turning out.

Jwalker next time your in Buckie drop past and we will gladly show you around with tea and tunnocks

Colin

[C-NUMB]

Very interesting design, as also good looking. The steps are totally different from the usual ones, not only at keel line. Actually it is kind of difficult from the pictures to understand their shape(at least for me ). In the "ordinary" steps, aft part of each step close to the chine is typically higher up than the previous one. Here it looks like they are more or less on a even line. So is the step created by kind of a warped surface?

[macandrc]

Originally Posted by C-NUMB

Very interesting design, as also good looking. The steps are totally different from the usual ones, not only at keel line. Actually it is kind of difficult from the pictures to understand their shape(at least for me ). In the "ordinary" steps, aft part of each step close to the chine is typically higher up than the previous one. Here it looks like they are more or less on a even line. So is the step created by kind of a warped surface?

The white paint makes it very difficult to see the key features, the Durabuild primer is a dark grey which will hopefully show the hull in its full glory. As you mention the steps on the Interceptors are different to traditional stepped hulls, the hull line is continuous with the steps interrupting in a delta format. You could call it a warped shape, it certainly was a pain getting the materials to contort and bend to the shape! I have attached an image which might help out.

Colin

[C-NUMB]

Originally Posted by macandrc

The white paint makes it very difficult to see the key features, the Durabuild primer is a dark grey which will hopefully show the hull in its full glory. As you mention the steps on the Interceptors are different to traditional stepped hulls, the hull line is continuous with the steps interrupting in a delta format. You could call it a warped shape, it certainly was a pain getting the materials to contort and bend to the shape! I have attached an image which might help out.

Colin

Thanks for the picture, think i more or less get the shape now. Will be interesting to see the ready product at some stage!

[macandrc]

Here are a couple of pics for those following progress, the photos are after the first couple of coats of the Durabuild primer. We ended up putting 3 thick coats and started sanding it all back to a shine today ready for machine polishing.

Hopefully the attached pics show the shape a bit clearer than the previous pics when the hull was painted white with the sealer.

As always we welcome your comments/questions

Colin

[Xk59D]

very interesting and thanks for uploading.

may i ask what is point of the tubes if they are not ever in water?

or what are the pros and cons in your view of having the tubes in the water?

cheers

[Maximus]

Originally Posted by Xk59D

very interesting and thanks for uploading.

may i ask what is point of the tubes if they are not ever in water?

or what are the pros and cons in your view of having the tubes in the water?

cheers

They may not be in the water at Standstill...on Calm water...there's the clue!

[Barry Carson]

Originally Posted by Xk59D

very interesting and thanks for uploading.
may i ask what is point of the tubes if they are not ever in water?
or what are the pros and cons in your view of having the tubes in the water?
cheers

Thanks for the question. It is one I have been asked many times, particularly in the early years of designing and building my designs. Before specialising in ribs I was a more 'traditional' designer/builder working with anything from sailing craft to work and fishing boats. Moving into ribs in the 80s it always struck me as odd that considering an inflatable was then being given a solid (usually grp) hull to enhance performance it seemed to me strange that others were at the same time taking away a couple of big advantages a solid hull offered, further reserves of bouyancy and stability. Some even flooded their hulls to gain stability when at rest by resting on the tubes.

Previous to ribs well designed boats had adequate stability and bouyancy by way of their hulls only and I reasoned this should remain the case with ribs. Hence my designs have always had hulls that were in themselves stable and bouyant without relying on any tubes at all if it came to it, say through mishap or damage to a tube. We proved this by launching an early Carson 6 metre and drove it around Liverpool docks BEFORE the tubes were fitted. This feature can be especially seen in my larger ribs as posted here.

I was often criticised for this approach in the early days and attempts were even made to bar Carsons from racing and some other events. Needless to say these attempts failed and nowadays it is a very common design feature.

Other advantages of keeping the tubes clear of the water are that they are saved from the worst effects of wave flotsam impact and weed groath accumulated when kept afloat. This is particularly important with ribs that like all Carsons over 5.5 metres can achieve speeds of at least 50 knots. I'm sure you'll appreciate the forces are considerable and even the strongest fabrics will eventually fail.

Soft cushioning fendering is another reason for having tubes and a big plus for boats that are used for boarding other craft. When inflatable conventional tubes are used they also save weight and with larger ribs may be deflated when towing on the road, particularly useful with bigger boats when their inflated beams exceed legal limits. Even our 750, 850, 900 and 950 models can all be legally towed when deflated. They also fit into containers for shipping and for the military be put inside transport aircraft.

The main down sides of tubes are 1 their cost and 2 their relative vulnerability compared to other types of craft's sides (grp, alloy, steel and wood, etc).

[Barry Carson]

Not sure what happened but not all my reply came up on my previous post:

Huge reserves of bouyancy and stability are of course other big pluses for having tubes. Very useful when you may be having a bad day!

And apologies for typing errors: groath should read growth

[gtflash]

Hi barry. What is the purpose of the flat keel line? Does it work like a small planing pad?

Thank you for your time to explain things to everyone. It's so nice to have someone with so much knowledge, who shares it.

[Barry Carson]

Originally Posted by gtflash

Hi barry. What is the purpose of the flat keel line? Does it work like a small planing pad?

Thank you for your time to explain things to everyone. It's so nice to have someone with so much knowledge, who shares it.

Thanks for the question gtflash. To a small extent the flat keel line does work like a planing pad as any flat surface area would. However this is not its prime purpose. We offer the option to fit a stainless steel keelband to allow beaching or grounding and some hull protection when transported on trailers with keel rollers. Many military users specify this option.

The wide keel form also allows us to build more strength in this crucial area and spread impact loadings over a wider area. Eliminating the planing pad also offers a softer re-entry when the hull jumps clear of the water. Kinder on the boat and the crew. These Interceptors while eminently suitable as medium speed workboats are also designed for very fast open water operations (as the name implies).

Many of my other designs do have planing pads (as well as the same flat keel lines as here) to assist in getting a heavily loaded boat onto the plane and staying there at relatively low speeds. However with these Interceptor model which have a very deep V of 24 degrees the planing pad is replaced with broad spray rails, 4 in the after part of the hull and typical of all my designs there are wider 'gullwing' spray rails or chines running the full length of the hull. In addition to assisting getting on the plane and achieving more speed and economy for a given horsepower they also add enormous stability both at rest and speed and assist in throwing spray out and clear to produce a drier than normal ride.

I hope this answers your question and thanks again for asking.

[macandrc]

Hi all it was suggested that i should post this update here as this was the original thread. As you will see from the info below its an exciting times with us at Probond Marine

CARSON INTERCEPTOR BREAKS THE MOULD
The last few months have been a particularly busy time for Probond Marine Ltd. After recently completing new moulds the first of the CARSON INTERCEPTOR 950 Class is now being fitted out. Designed by Barry Carson and developed from previous designs supplied to many special forces and other professionals over three decades, all the familiar Carson design features are here and further developed to provide even more performance and seakeeping abilities. The Interceptor's distinctive 24 degree deep V hull with gull winged chines, multiple steps and semi wave-piercing bow can be seen in the attached photos. Various collars are offered with this first hull to get a D section collar mechanically attached to the outside of the raised topsides as per the 3D image here and posted previously. Conventional collars are also an option as well as foam filled and a choice of welded PU or glued hypalon fabrics. 850 and 750 (8.5 and 7.5m) models are soon to be available. At the time of writing this hull has already been framed out with full depth deck to hull bulkheads, longitudinals and frames. With an easier motion and drier ride than other similar sized craft coupled with potential for very high speeds and cruising range of approx. 1,000 miles this design provides many advantages for a wide variety of operations. We will post more photos as we progress the build.

[sailrib]

Very interesting shape, please keep the updates coming. Looking forward to seeing it on the water in anger.