Is bulkhead tabbing now redundant?

What is dull and boring about seeing what is expected ?
Get used to it ,I have worked to these types of standards for maybe more than 10 years , this will become mandatory in later years and if you cant hack it now you're going no where !! these people set a standard to be followed . I would rather buy a boat that has a DNV certificate of approval than the same type of boat without one !! .

 

I did the same once.
On a 13 ft canoe

 

where did the DNV guy learn to be an expert?

 

Compliance is mandatory already - only not everywhere in the world. The exception of self built (and/or uncertified) boats needs to be tolerated.

Sorry for my previous attack on Chinese products, and let me be more specific:
Would you say that without you and perhaps other expats in your company, this company would in future constantly (once unobserved from outside) produce good quality?
Surely, i.e. DIAB foam from China is top quality; but not because of China and not because of the Chinese, I believe. I have seen the opposite case many times and feel extremely suspicious. We can talk about it further, but here is not the right thread.
I do not attack you personally, to make that clear.
However, you may be exposed to censoring and you need a work permit as well .............

 

Has been since year dot, in the commercial world. The leisure market is slowly being forced to comply with these similar minimum standards of vessels in the commercial field. Those unfamiliar with such procedures tend to cry fowl in one form or another as it means more work for them.

 

yer but in the world of steel ships the standard has been on a downhill slope for years
What do the decent megayacht yards say...sorry we dont build down to class

 

Do those who cry fowl feel hen-pecked by regulation ? Sorry, couldn't resist adding my poultry contribution.

 

its not a problem
class survives 100% on new builds
Class relies 100% on your money
you can make them bark like a dog hence the cheapest bid wins after they have decided to do what I tell them
thats how it works
Class is a flawed system, for profit organisations with no government oversite

 

Can you please define this statement better, what standard what ships?

Because generally they don't build to Class other than basic structure. Most yachts of yesterday would not pass most Class rules, when fully applied. This is the main reason why the leisure market is slowly changing because the rules are changing to enforce compliance.

Most yacht standards are purely visual and outfit driven..very little else. Structure is an unfortunate necessity, for example!

 

read an experts view
http://www.c4tx.org/ctx/pub/tromedy2.pdf

If you work on commercial vessels like I did but still work in the industry we all agree 100%
I work in the offshore AHTS PSV and other DP vessels
You can build one that will have a working life of less than 10 years that makes everyone happy
I worked with an owner that had a 5 year profit plan then scrap 4 80m AHTS's they cost alot to maintain just to get to there. I worked on them brand new and the 5 year old ones.
That owner also bought 10 2nd hand 20+years old vessels, they are still perfect.
Yard gets to build more, class gets more new builds owner gets cheaper boat
they are way to thin to survive and are full of cracks in a very short time especially if the design is bad.

 

No, that was my point, design engineering can only take a design so far, the real proof is when the boat is put in service.

You, in addition to my engineer friend, both said one needs to prove the method is good enough when doing something new or in a way thats not considered typical.

This is the problem... if everything is always done the same way, how can we ever improve upon that? We cant, so at some point, whether in a testing laboratory or in a real boat, the new method must prove what its capable of and where the new limits are.

From what i can gather, reading etc. Tabbing bulkheads to hulls, is a legacy method of solving a problem. I say legacy, because it evolved from the days when fibreglass boats were built almost exclusively from polyester resins and lots of CSM or roving reinforcement. Now i do understand what your saying about switz cheese and parma ham, but you need to understand what im getting at here... and that is the method of solving the problem was to fibreglass tape everything - because the materials did not have properties good enough to solve the problem by other means.

Now that materials are stronger, and laminating techniques are better - resin infusion etc, did anyone even bother to analyze whether the legacy method was really still required? or has it in fact now become overkill? I suspect the latter, as people simply started using the new materials will full confidence knowing the properties were better - so no risk to them. What DIDNT evolve, was their manufacturing techniques - they were in blissful ignorance, happy with a system that worked for them, most people are reluctant to change from what they know best - Tunnels is a perfect example of this

This is what i mean by pioneer - im not happy simply building a boat, i want to build a better boat, with better methods, minimum weight, better displacement length ratios, lower fuel consumption etc - look at how much has changed in the automotive industry in the last 30 years. Why is the marine industry so far behind? Why is marine engineering with composites, still done to a 350% safety factor, when aircraft composites are manufactured to a 10% safety factor? Rhetorical question - i know the answers, but do you? Tell me...

 

I think you’re getting somewhat confused. All one is doing is using a material that has yet to be proven satisfactory for use, that is all. There is nothing “taken so far” in that. Composites are anisotropic as such any deviation from a known quality requires investigation. It is called engineering and not guess work.

Who said everything is done the same way? You need to address this with those you have some issues with; since you’re tarring everyone with the same brush.!

It is not a new method, it is just a new “mix” of the same or similar materials in a combination that is as yet unproven. Unproven meaning rigorous testing to ensure it does what is expected; as noted above. It also does not mean it is pioneering in the sense you’re alluding to. There are simply endless different mixes with composites out there that never see the light of day…why?...because the designer who though….like you..hey, let’s do XX and YY...and see if we still get better than Switz cheese and Parma ham. Once their new mix has been formulated, several issues become evident. Cost, time, fatigue and approvals and of course availability. Thus unless the new mix is commercial viable, regardless of its technical prowess, it never surfaces to the wider public. Starting with a blank sheet of paper may appear wow or romantic to many “anything is possible”..but the down side is the realty of knowing what it really can or cannot do! Even with aluminium, there are endless different alloys, even though it is an isotropic material testing and more testing is required.

A new structural design, not thought of before, is no different to a new composite. It is not "pioneering", it is "engineering" by those who understand the disciplined nature of design and manufacturing to be successful.

That is down to many many factors and highly subjective too, but, none of which has anything to do with just a new mix of materials. A better boat can be boiled down to one word….Quality. But, it crosses endless disciplines and is not the role of just one person and one detail, but everyone involved. A boat is far greater than the sum of its individual parts.

I think you should look at the sums of money invested in car and aircraft manufacturing and the number of units made, compared to the marine industry. That’ll answer your question.

 

do people still use plywood tabbed in bulkheads in boats?
wow

 

Agreed Adhoc, And perhaps you also equally myopic...?

As i know you have a romantic view of engineering... why avoid the key point i was making? That is, if 2 engineers are both using the same parma ham and switz cheese, - why does an aircraft engineer apply a different safety factor when designing a composite structure, to that of a marine engineer?

The reason foe this, is the same reason we have boats driving around the seas, burning more fuel than they should be, costing more to build than they could otherwise, and are less sustainable in general.

 

Different environment, different quality control, different loads, different levels of safety and so on. Since if you wish to complete this circle, I assume you will crash you boat at 50km/h into a wall several times at different angles of approach, to see if it passes the crash test for example?