can it be done in steel?

With respect I disagree as hull design engineers and fabricators consider that as it being very relevant.

I wouldn't apply the fabrication lay up of a aluminium 10m weekend cruiser to a 50m crew vessel or patrol boat operating off shore for extended periods - build a 50m Armidale with same rules as a 10m alloy tinnie.

 

MikeJohns, thanks, I should have known these rules but, the truth (and it is a major fault) I did not know them.

Titirangi, one thing is the rules to be applied to a ship based on its length, the material of the structure, the service and boat work area, and another very different thing is that the welding separation depends on the length of the ship. Do not confuse things, please. I also made ​​a mistake and I've recognized.

 

Understand where you're coming from, personally I apply the rule that over rules all others - common sense.

I build my hulls to meet the requirements and with a view to myself or others later down the road having to refit my construction.

 

Here we enter another discussion which is also very interesting. To what extent to catch the more restrictive rule, the maximum required safety factor, and multiplying by "x" (x>1) is a good practice?
Is this a good practice or a way of avoiding our insecurity in our work?. I guess there are many opinions. What do you think?

 

Insecurity in our constructions is not how I would view work practices. Structural rules and fabrication standards are just that, as you described are a minimum safety factor.

My attitude towards hull construction and installation of ships pipe/electrical systems developed from my experiences refitting and repairing badly built vessels.

I would like to think owners recognize the thoughtfulness and effort we put into our projects that gives them more value for their investment than others might and secure knowledge that the vessel meets all their expectations.

I've been brought in to review new build projects in some yards by the owner dissatisfied with standards because the yard attitude is near enough to pass survey is good enough and if the yard could gain extra profit with a little cheating all the better.

 

Most of us would consider the scantling rule requirement as a bare minimum rather than a optimal target. But I like to work out what factors of safety the various rules use. I often run my design work through a spread sheet that uses my factors of safety on design from first principles, especially if the apparent class result looks a bit light or overly heavy. Sometimes the rules are not very clear until you have some experience.

There's a classic case of class rule interpretation problems at all levels here:

http://www.boatdesign.net/forums/metal-boat-building/massive-stem-bars-why-31955.html