Adapting projects

[ruysg]

Hi there,

This is my first post, so please excuse me if I'm to off track. I recently graduated as a Naval architect here in Brazil and got a job in one of the biggest luxury powerboats company in the country. Are boats are between 40- 80 ft

We don´t do actuall design here. We receive the plans from Italy, together with a hull and deck, and all internal parts and furniture. However, we don´t stick to those plans. The hull is usually extended, interiors are changed, engine room layout changed, among other things.

What amazes me the most is that these changes have almost no planning. They are decided as the boat is built. Position of hardware, hull fittings, cables, wires, eletrical system, hydraulical system, interior design and finishing are all figured out while building the boat, on the boat, meaning a lot of work has to be done over and over. Plans, skechts, drawings? Who needs those?

I´m fresh form school so this seems kinda of crazy to me. I was just curios about how this is done in other places, especially adapting projects.

Ruy goncalves

[rwatson]

It does sound strange, but in some countries they build 40 - 60 ft timber boats with NO plans at all (eg Arab Dhows). Its amazing how experienced builders develop a 'feel' for changes, developed over the years of building.
With boats of that size, they probably dont have to worry a lot about the effects of weight distribution like you would on much smaller boats.
I also expect that the lengthening of the hulls is done in the centre where the frames are pretty uniform and you can basically add a couple of stations to get another 5 or ten feet out of the hull design.

Even so,your point about making mistakes because of poor planning is valid in any industry. Never time to design, but always time to do it over again.
I imagine the economic rationale is how much it costs from mistakes, versus how much it costs for a full design service.

have you brought up the subject with your supervisors? What is their view?

[ruysg]

We actuallty do the hull lengthening cutting off the stern, bringing it back a meter or two and fairing out the lines. No that you said it, ot does make much more sense to add station closer to the mid body. However it seems a little bit harder to do.

Every time I ask why are things done this way I get answers like "We´ve be doing things this way for 30 years, it´s just how it´s done". Kinda of a poor excuse to me.

On the economics, nobody never actually made the math. I thinnk the if somebody did it (I never did, maybe I should), they would find we are throwing away a lot of money. My supervisors believe the contrary. Having a proper team for design (not even the whole design process, it´s just adaptation) is not worth it. Kinda of hard to believe.

Never time to design, but always time to do it over again.

That seems to be another reason why we don´t do the proper design, there is alway a hurry on getting the boat done yesterday. I guess on the long run you actully end up taking more time this way, not less. Interesting that the owner of the company classifies the engineering department as "non productive". I guess we are a bit carried off by the good economic moment in the boating industry here in Brazil, wich allows us to charge a lot for our products to cover our high costs.

My boss actually has lots of experience and has built many boats, so he has some "feel" for changes, but I recently found out the most of the designs (maybe I shouldn´t use the term) that came out of the yard had have the hull extended or cut off due to poor equilibrium.

Another problem in this system is documentation. As the decisions are made on the shoop floor (that´s a translation from portuguese, sorry if it doesn´t make sense), there usually not registered, so we have production boats wich come out different each time. Depping on wich worker was building the boat that day things come out different.

By the way I was wondering: is their a way of getting o decent lines plan of a hull with laser scans, or something like that? I'm talling about an 85 ft.

Thanks for your comments rwatson, nice to know I´m not crazy.

[TeddyDiver]

Position of hardware, hull fittings, cables, wires, eletrical system, hydraulical system, interior design and finishing are all figured out while building the boat, on the boat, meaning a lot of work has to be done over and over. Plans, skechts, drawings? Who needs those?


Sounds so familiar:D Sorry I'm joking.. Not even an amateur boatbuilder (like me), allthough I'm studying and planning the subject while building, manage without some kind of sketches and calcs..
And Yes, it's possible to laser scan a boat..

[rwatson]

And Yes, it's possible to laser scan a boat..

Name two devices and their manufacturer!

Obviously its theoretically possible, but do you have to build the device yourself?

[marshmat]

I've seen the devices but have never used them, so can't recommend any particular one.

The problem with last-minute changes is bad in many industries. Construction, for instance, is among the worst. Thankfully, many countries have building codes which require a certain degree of compliance to recognized standards and design principles; thus, the engineers and architects who have to sign off on it all tend to write the need for engineered designs of each system right into the contracts.

Still, there are always four versions of any design. There's the original designer's drawings- "design intent". There's the constructor's shop drawings. There's the fabrication lists and order sheets. Then there's what the guy with the hammer actually built, which vaguely resembles some combination of the above....

[ruysg]

Well I´m trying to convince my boss that planing is worth it. What software do you recommend for fitout, pipework, eletrical and other systems? Something I could use to plan and manage to construction process. And some weight control to.

Thanks everyone

[ACuttle]

Laser-scanning is very possible for any small vessel of that size (though there is nothing to stop you scanning a larger vessel but access is more of a problem and it just takes more scans). I've worked on several similar projects including scanning of 15m-20m tugs and trawlers. As long as you've got the space to work around the hull the scanning itself is relatively painless (though generally cold in gloomy British drydocks).

Depending on access you could scan the exterior of 30m boat in about a day, which would give you more than enough information to produce a set of lines plans. There are plenty of applications for the technology for quality control, documentation of hull especially if time or changes have left the old documents obsolete (or just lost) and planning for repair/conversion work.

rwaston - I think if you could build a good working laser scanner yourself you would need to worry about staying in ship-building. The Faro LS880 units are good to work with and I think the Lecia versions are pretty similar too.

Though I think you'll find it very hard to make too many changes in a yard with ingrained working practices like you've described. Experience will trump an awful lot of other aspects but can also benefit when design processes are put in place to help the method.

[ruysg]

We are working on a new 85 ft hull, an extension of a 76 ft we have, that is also an extension of a 70 ft from Italy. We are probably gonna laser scan the hull. We've found a company that does the service. The usually do scan of ship hulls for repair purposes. Don't know what equipment they use, as soon as I find out I'll post it.

Now at least there is gonna be a good starting point to design all interior layout and systems. Looks like I'm gonna be busy.

[BHOFM]

A last minute change in a overhead walk way, killed
over a hundred people in Kansas City some years ago!

http://en.wikipedia.org/wiki/Hyatt_Regency_walkway_collapse

[ruysg]

Hi there.

The hull plug has been scaned by a Faro laser scan. The whole process took about 3 hours, pretty quick. The guys doing the laser scan also did the post-processing of the point cloud, generating stations as polylines. This is pretty sweet. The job cost about US$ 7000.

BHOFM - And those guys HAD a plan that got changed. Imagine when you don't have one...