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Old 09 March 2003, 19:08   #201
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Country: UK - England
Town: scotland
Boat name: Leviathan
Make: Phantom
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Engine: GM Diesels
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!!!!!!!!!!!!!!!!????????????
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Old 09 March 2003, 19:25   #202
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Country: UK - England
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JF if your saying you know everything about putting this engine forward and your unhappy that I have given any bad advice say so.

I am not a designer/builder or even purport to be one, but I do know a little about the problems of conformaty to the new RCD Iso regs ,as I have had to comply with these and I have taken into account what I know and have been advised.


I am not questioning your personal knolledge on racing hulls or there developments as I have no experience.

I am sorry for not being in the experienced in what makes a raceing boat go faster but it is not my interest as Ribs are.

I have spent too much time on this simple advice which is get advice if you want to move your engine forward from those that you feel happy and you feel are experienced in doing the job properly.

I mean no insult to anybodys knolledge on this subject but can only say what I woud do if it were mine, as I am looking at it from potential user/future buyers point of view.
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Old 09 March 2003, 21:15   #203
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CH,
I'm not saying that moving the engine forward in JW's boat IS the correct thing to do, as I have no knowledge of his boat at all!,
All I'm saying to you is, that to install an engine forward of it's standard position may be the correct thing to do if the C of G looks like it may be too far aft as ballance is critical to both speed and rough water performance, this may be the case if the engine in question is heavier than normally fitted or any number of other reasons.
The kad300 may be perfect for his boat as standard, I hope it is,
Just don't assume it's the wrong thing to do coz you havn't seen it before, or it wasn't suggested by a rocket scientist (or a tosser in brussells)

Love, johnny boy

P.S. Anyway, it sounds to me like JW has his own opinions on the subject, so I'm sure he will take no notice whatsoever of a couple of nobs like us. Amen
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Old 09 March 2003, 21:34   #204
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Quote:
Originally posted by Dirk Diggler
Oi, your at it again, this morning you had a pop at Scorpion, now your having a go at Lorne Campbell!!
Sod off Giggler!
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Old 09 March 2003, 21:34   #205
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Country: UK - England
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Join Date: Nov 2002
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I think he will agree with you as its to late for any real changes in spec or implications of RCD and all that sort of stuff and who wants to know what I am suggesting could be important.

I wish him well whatever decisions he makes.

Be happy
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Old 09 March 2003, 21:35   #206
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Ditto!
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Old 09 March 2003, 21:37   #207
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Are we done with that one then?
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Old 09 March 2003, 21:40   #208
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Country: UK - Scotland
Make: HumberOceanOffshore
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Engine: Volvo KAD300/DPX
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Wow, started something there.

I'm not siding with anyone on these next comments.

CH, I DIY everything. The old adage, 'If you want a job doing properly, do it your self.' is me. I'm constantly amazed at how dopey professionals and experts can be. Even things which are obvious to others are often missed or not understood.

Originally posted by crazyhorse
"but to try and move a engine forward cos you think it will stop a sea from comming over the bow? is not recommended."

I don't think I said that.

Let me pass this one buy you.
Example 1,
8.5mtr hull and tubes CG just rear of mid point. Now, inboard at the stern, engine wt. 550 kgs. Consol well forward and 6 people on board sitting at the console each weighing 12 stone. (= 480kgs).
So, now you have 500kg at the stern and 480kg near the bow.
Where is the CG?

Example 2,
Same hull, engine moved forward 1.5 mts. Me and wife sitting just forward of the engine our weight 146kg.
Where do you rekon the CG is now?

CH the above is not indicating critisism of you in any way. But its a very simple example of how reasoned estimates can be used to help solve a problem.

However, I'm open to any sort if insight into problems with the boat, which may be forseen by others. 'Two heeds is better than yin.' Forget Cat B, resale value etc.

I've tried not to upset anyone. Hope I managed.
JW.
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Old 09 March 2003, 21:42   #209
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Yep for the moment, till the next subject

I am in seriouse myer with her indoors so will be off line for a bit as I got to get my priorities right.

Tarra
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Old 09 March 2003, 21:45   #210
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You have upset the other half,Have you a weight table for the boat with a Kad in her?
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Old 09 March 2003, 21:49   #211
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As my old pal Dirk says, "I'm always in the s**t, it's only the depth that varies"!
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Old 09 March 2003, 21:50   #212
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Hi CH,
No I haven't. I think Humber use fag packets. Just guessing.

Apologies to your wife.

JW.
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Old 09 March 2003, 21:54   #213
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Ok well good luck with it JW I can not help here as it takes to much time and is a specilist job to give you a good chance of success.

Will Humber help?
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Old 09 March 2003, 21:56   #214
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I will pop mi bit in tommorow after i get the wifee/ partner sorted

Taraa
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Old 09 March 2003, 22:09   #215
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CH, I'm not sure you understand real DIY. It's not MDF and emusion paint you know.
Sleep tight.
JW.
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Old 09 March 2003, 22:15   #216
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The best advice I can give is speak to Ace marine in FiFe.they are stability consultants and Naval architests and see what the costs are for a accurate Centre of gravity of the boat with all the gear in her,and the best place to put the Kad 300 and tanks.

They may be able to help but without a weight table it may cost more.?

If your not interested in RCD then freeboard doesnt matter.Its just the best position for the engine.

You will feel happier and so will I.

Should cost not more than £200.aprox Maybee,Hopefully?
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Old 10 March 2003, 06:48   #217
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JW
Ok having slept on your problem about where to put the engine/tanks,I can confirm that in my humble oppinion that given the Hull weighs aproximatly 1 ton and the engine weighs over half a ton and we floated a 30 ft rib that was down by the stern with a Kad300 in her in Autoship and she was realy low at the back end,in fact the water was 4 inches up the tubes.I can say you have in my oppinion no alternative than to move the engine forward or the nose will be in the air with just the two of you. I am no stability expert,and have advised of one I personaly can recommend .IMHO

It is critical that the engine/tanks be placed in the right place and I have recommended who I feel can help with this important decision and they can give you a weight table given accurate imformation and work out a accurate CG.

If you are a very competant DIY er then good luck with this project but my experiance of Competant DIY ers boats is not impressive.



Good luck with it and I hope it works out fine.
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Old 10 March 2003, 08:33   #218
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Ere, CH, it looks like you've done a bit of an "about turn" on this one! I'm impressed, that takes guts!
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Old 10 March 2003, 08:42   #219
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Posts: 1,012
No about turn but its a big job and needs somebody who knows what he is doing,Maybe JW does and I hope so,but if not then its talk to a proffesional if you want a chance of succes.Its not my boat and there is a lot of decisions already made that I would not make personaly. I have the Kad drawing of a 30 ft with a Kad in her and will show you what it looks like when floated in Autoship , it has the engine at the stern with a lot of weight up front

This project is not for the faint hearted or them that guess.

Be happy
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Old 10 March 2003, 09:04   #220
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OK CH, but you're still putting all these "alleged" gods of techno on much too higher pedestal! you must accept that there are plenty of people out there with excellent "gut" feelings on this stuff, who will very often show your pen & mouse pushing consultants a thing or two. That's not to say some of them aren't brilliant! The designer I mentioned earlier in this thread, Bill Malloney, is exactly that, most of his stuff is a combination of "gut feeling" and "mathematical know how" if his 31 footer hits the water, I'm sure it would be a fabulous rib.

Regards,
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