proven hull

[idham58]

when we said- 'The design proposed shall be based on a proven hull', what does it means?

[daiquiri]

Sadly, they don't want you to get too fancy or to propose innovative solutions.
Use one of well-documented standard systematic hull forms.

[PAR]

Well I'm not sure what the context of the original comment was, but typically, it would be just as it sounds; a hull form that has undergone considerable trials and development. This isn't unreasonable, nor unexpected, particularly for certain SOR's.

As a client, you'd have to pay to develop a new, cutting edge hull form, which most can't be bothered with, because of the costs involved, unless they can justify the expense. Racer's do this all the time, as do cruisers interested in something quite specific, that's not addressable in production or semi custom craft.

Every designer bases proposed projects on the successes of previous hull forms, so again, not knowing the context of the comment makes the statement ambiguous at best.

[Mr Efficiency]

Yeah, without seeing the context, not much can be said. Could just be about designing a different interior layout for a boat without changing the bit that meets the water.

[daiquiri]

Originally Posted by Mr Efficiency

Could just be about designing a different interior layout for a boat without changing the bit that meets the water.

That sounds improbable, imho. The wording here implicates a design of a hull, the requirements for interior layout are usually contained in a separate chapter of the SOR.

[philSweet]

contractually, it is meaningless. It is similar to a "commerciality clause".

I snuck the following wording into a contract in '87 and it was discussed for two years at legal, contracting, and industry confabs. In the end, it mostly failed to do what we were trying to do. It was never actually challenged in court, but a protest to the award was based on the claim that the awardee did not comply. This forced us to take a hard look at where you draw the line. IIRC, the protester claimed the awardee recalibrated a turbo waste gate to increase rated engine power. I agreed with the protester. My boss did not.

"Commerciality. The manufacturer shall be experienced in designing and building scoop loaders and shall have sold them to the general public at least one year prior to the opening date of the solicitation. Upon request of the contracting officer, offerors shall submit evidence of the commerciality of their machines in the form of catalogs, commercial brochures and data. Additionally, these bidders shall furnish names and addresses of nongovernment sources which were sold equipment at least one year prior to the opening date of the solicitation. Equipment and configurations covered by this paragraph include the basic vehicle configuration (body, engine, tires, cab, counterweights, coupler and all buckets) as well as either; 1. All equipment specified in ordering data, or 2. A minimum of 15 optional and allied equipment items applicable to 4 yard loaders which are described in paragraphs 3.24.1 and 3.24.2."

Basically, there are too many individual items to be proven and one must agree what constitutes proven for each item and combination of items.

[tunnels]

Originally Posted by idham58

when we said- 'The design proposed shall be based on a proven hull', what does it means?

It means just what it said proven means you know how it goes because it is a actual boat . as long as you dont unballance the boat from what the original boat is you all ready know what it will perform like with what ever hp ot has got .
to improve make it lighter in construction and dont fill it with all the usual junk people think they need when they go boating .

[Alik]

Proven hull is one of widespread myths about boats. Proven - for what purposes, what speed, what load, etc? Most of time demand of 'proven hull' is ridiculous; unfortunately seen in many tender documents.

[daiquiri]

Originally Posted by Alik

Proven hull is one of widespread myths about boats.

Originally Posted by philSweet

contractually, it is meaningless. It is similar to a "commerciality clause".

Well said. It is one of those terms written by lawyers, surely not by engineers or NA's. It probably serves more as a weapon for eventual future legal quarrels against designer/shipyard than as technical guidance.

A given hull can be said to be "proven" if it has been extensively tested or used under certain operative conditions. Change those conditions and it is not proven anymore. Make (for example) the water depth, wave height, encounter frequency or angle change by so much, and your proven hull becomes un-proven again. Similarly, change the distribution of masses inside or above the deck of a proven hull and you have an un-proven ship (which is hull plus all the rest) again.

Cheers

[PAR]

How many commissions will be contracted if the statement was "The design proposed shall be based on an unproven hull" . . .

[Landlubber]

'The design proposed shall be based on a proven hull'

...it is basically saying that the purchaser is not interested in experimental hull types, or anything radical, it is a simple clause, to state that the purchaser wants a vessel that has been previously built and has withstood the test of time to not have obvious faults, handling problems and meets the required speed spec as has been seen by previous models on the water.....not some NA concept drawing or anything radical and UNPROVEN.

...I have seen this clause many times in commercial specs, it makes perfectly good sense for the purchaser to request such a thing, and I personally do not find it to be a useless statement, it is simply a statement of intent on the purchasers part, to have a vessel built that has a track record of being good for the purpose of the build.

[m3mm0s rib]

Means that action should confirm the theory, though sometimes the theory remains only on paper

[philSweet]

I think if you end up in arbitration where a failed bidder challenges the award based on the provenness (if that is a word) of a winners design, you may be in the awkward position of having to explain exactly how you determined that the winners design was proven. If everyone agrees to play this game and play nice, it makes for a "barrier to entry" which may suit all participants.

[Ad Hoc]

I have seen this phrase more times than you can shake a stick at it...

The irony is, in the same breath as "proven hull form"..the client list endless "wishes" into their SOR which render the "proven hull form" impossible to satisfy.

When i buy a car, i wish to buy a car at today's technology, not old hat. So would I buy a brand new car based upon years of previous designs or a car from the 1980s simply because it is still running around, ergo the 80s car is proven!!.

Whereas the new car of today is seen as "different"....go figure...

That is where all the cost over runs on military spending goes, and your tax money. Idiots who havent a clue and an open cheque book to "get the best" whilst failing to understand cost and performance with such pathetic wording; "proven hull"!

[CMS]

Our experience is that the client wants to be able to see a boat of the same design already in the water. They may accept slight alterations to length beam and draft but not much.