Peer Review

[MikeJohns]

If you design to class then an essential part of the process is to submit your plans for review. Then at least you get the structure reviewed and ensure you are interpreting the rules correctly. After 2 or three of these you should have most of the bugs ironed out for that class of vessel and construction material.

I've surveyed leisure vessels so called "designed to Lloyds A1" and on lifting the cabin soles seen framing errors that would never have passed plan review.
When there are obvious errors then sometimes the building yard just does it properly, sometimes they stick to the plans. But in Australia the yards are much more transient and the workers flow between boat building and other jobs and will unthinkingly build what's on the specification. I've seen some very expensive mistakes that had to be rectified, that would have been picked up by a foreman in the past.

Some designers try to do the simple calculations but confuse material properties. Simple errors like Like confusing Ultimate tensile and yield. Those with experience pick that up with a glance at the calculation just because they are very familiar numbers .

But there's nothing better than having someone look over your shoulder pick up your drawings and say " you could improve that by ..." or " there's a mistake here.."

[Oyster]

Mother Nature is probably the most credible source if you are looking for an unbiased review. By the way, this thread is filled with quite a selection of sources too.

[mcollins07]

Originally Posted by tom28571

I think it would be very instructive for any considering pursuing the peer review idea to go back and read ALL of the material on the "Option 1" thread below. For those not familiar with this exercise, it was an attempt to do a cooperative design of a particular type of small powerboat. The first obstacle was to agree on a fixed set of design parameters that the design should adhere to..

Thanks for pointing this thread out. I had not looked at it before since I'm usually interested in sailboats. However, it is very relevant to a discussion of collaborative efforts and methodology.

Originally Posted by tom28571

...
I think we all learned quite a bit from each other but we could never agree on what an optimum boat would be for the intended use. As a result, each person went their own way with some actually building a boat to satisfy the intended use from their personal perspective..

I did not read the entire series of threads. It was rather long. However, it appeares to me that there was never agreement on the intended use. I would suggest that a group must focusing on getting agreement of intended use before getting into any parameters, specification or requirements of the boat itself. Agreement on the type of boat does seem to be a success in the Option 1. Perhaps dicussing parameters before getting agreement on intended use was a distraction.

[ancient kayaker]

Originally Posted by MikeJohns

... Some designers try to do the simple calculations but confuse material properties. Simple errors like Like confusing Ultimate tensile and yield ...

Reminds me of my first few days at an internationally prominent aerospace design house. As an electrical engineer I wandered through the mechanical engineering section to see what they were working on and they were tearing their hair out over the stiffness of a monster robot. I took one look at the resonant frequency (think wet noodle), then the construction (cranelike), and said I didn't believe the number, but as an elec bod I got tossed out. Not, however before I spotted the value used for Young's modulus, which was off by a factor of 10. They found the mistake eventually but I could have saved them some time and pain if they'd let me ... since then if I get daft results from my calculations I always review the fixed values for sanity.

[MikeJohns]

Originally Posted by ancient kayaker

Reminds me of my first few days at an internationally prominent aerospace design house. As an electrical engineer I wandered through the mechanical engineering section to see what they were working on and they were tearing their hair out over the stiffness of a monster robot. I took one look at the resonant frequency (think wet noodle), then the construction (cranelike), and said I didn't believe the number, but as an elec bod I got tossed out. Not, however before I spotted the value used for Young's modulus, which was off by a factor of 10. They found the mistake eventually but I could have saved them some time and pain if they'd let me ... since then if I get daft results from my calculations I always review the fixed values for sanity.

Simple little things like section modulus. Not realizing there are differing results for asymmetrical sections depending on the direction of applied load.

Screwing up a simple conversion of units like mm3 to cm3 putting them a factor of 10 out.

Here all the engineers often did a common first 2 years then specialize for 2 years. Consequently they were all very useful in any department and many would cross disciplines quite happily. Now it seems to be one common year and 3 years specialization and they don't cross over so well which is a shame.

[dskira]

Originally Posted by Oyster

Mother Nature is probably the most credible source if you are looking for an unbiased review. By the way, this thread is filled with quite a selection of sources too.

Unfortunately when Mother Nature gave Her verdict, its to late for some
I prefer Mother Drafting Board and Mother Calculation and Mother Engineering.
I will felt Motherly safer.

Just kidding at your expense.

Daniel

[MikeJohns]

It's observations of what mother nature destroyed that class societies base their scantlings on.

[ancient kayaker]

Originally Posted by MikeJohns

It's observations of what mother nature destroyed that class societies base their scantlings on.

Sounds like the traditional school of design. If it doesn't come back it doesn't get copied. Positively Darwinian. Beautiful in its way ...