3 ms·

I agree with everything you are saying, but I posit that even with that it is really "just cost". If the simple valve is not reliable enough you can design a m

I agree with everything you are saying, but I posit that even with that it is really "just cost". If the simple valve is not reliable enough you can design a more reliable one. It will cost you a lot. Maintenance is a cost too. (It costs you in crew time, crew training, materials, and tools.) And when it predictably goes wrong and that causes the ship downtime, and they have to cancel a guest visit because of it that is a cost too. So all of the things you list there (very good points each!) can be either mitigated by spending more on the initial cost of the valves, or by spending more on maintenance, or paying the price when it breaks. And I also agree with you that it very well might be the case that the benefits are not worth the costs. (Especially since when you are designing the yacth you can't know what kind of disaster will strike it. We could, in an alternative reality, very well be sitting here and talking about how they should have installed more automatic fire-extinguishers, or more redundant navigation, or protection from prop-fouling.) Engineering is hard.

short_sells_poo 2y ago
I think I phrased that badly. What I meant to convey is that a cheap and cheerful solution will need replacement at interval X, and a much more expensive solution will need replacement at 1.2X. At least in my experience, the relationship between the money spent and reliability tended to be logarithmic. In other words, spending more on fancier equipment didn't really minimize the main pain point of failures: the ship being unavailable for sailing due to maintenance. It was worse in fact, because more expensive equipment wasn't more reliable usually. Shiny lcd touch panels looked great but were a ballache to use when there was a swell. I had chunky 800hp mercury engines fitted to crack that magical 100mph barrier, but because they were fly by wire, we had constant issues with electrical contacts that were difficult to diagnose out at sea (unlike the older mechanically actuated throttles). Even worse, the more "over-engineered" a piece of equipment becomes, the more difficult it tends to be to reason about it's boundary conditions. More moving parts, heavier weight, more exotic materials - these all add further unknowns to an already very chaotic system that is seafaring. To come back to my electronic vs simple mechanical throttle system, the former is difficult to repair with a set of pliers, the other is trivial. Even though the former may have redundancies and fancy recovery modes, if it does fail, you are SOL. So you are right, ultimately it's a cost question in the sense that if the more expensive components aren't more reliable, why spend money on them. I was keen to make the point that I'd have gladly spent more money on said equipment to make it more reliable, but there seemed to be no correlation between the two aspects :D

short_sells_poo 2y ago

I think I phrased that badly. What I meant to convey is that a cheap and cheerful solution will need replacement at interval X, and a much more expensive solution will need replacement at 1.2X. At least in my experience, the relationship between the money spent and reliability tended to be logarithmic. In other words, spending more on fancier equipment didn't really minimize the main pain point of failures: the ship being unavailable for sailing due to maintenance. It was worse in fact, because more expensive equipment wasn't more reliable usually. Shiny lcd touch panels looked great but were a ballache to use when there was a swell. I had chunky 800hp mercury engines fitted to crack that magical 100mph barrier, but because they were fly by wire, we had constant issues with electrical contacts that were difficult to diagnose out at sea (unlike the older mechanically actuated throttles). Even worse, the more "over-engineered" a piece of equipment becomes, the more difficult it tends to be to reason about it's boundary conditions. More moving parts, heavier weight, more exotic materials - these all add further unknowns to an already very chaotic system that is seafaring. To come back to my electronic vs simple mechanical throttle system, the former is difficult to repair with a set of pliers, the other is trivial. Even though the former may have redundancies and fancy recovery modes, if it does fail, you are SOL. So you are right, ultimately it's a cost question in the sense that if the more expensive components aren't more reliable, why spend money on them. I was keen to make the point that I'd have gladly spent more money on said equipment to make it more reliable, but there seemed to be no correlation between the two aspects :D