Agree on the broken pump comment but... The bigger pump does exactly what you said - buys time while you make a repair. As you know it's not always as simple as sticking a nice tapered plug into a nice round hole. This is especially true in the event of a collision (shipping container, etc) where the temporary repair may take a little more creativity, time ... and trial and error. Obviously the further offshore the more of an issue this can become.
John Sent from my iPad > On Apr 14, 2016, at 6:10 PM, Patrick Davin via CnC-List > <cnc-list@cnc-list.com> wrote: > > Interesting. That's basically what I was wondering. I was looking for a > calculator, but I found > this: http://www.whsyc.org/Flooding/Flooding.html > > A 1.5" hole 2 feet below waterline results in 62.5 gpm (per minute!) = 3750 > gph. Even 4000 gph capacity wouldn't keep up with that, after accounting for > efficiency losses. > > So why do some people go for high bilge pump capacities? (like 2000-4000 gph > total) > > Sure it gives you a bit more time, but if I'm not at the boat it's probably > not going to make a difference (there's often no one on our dock for 12+ > hours between say 8pm and 8am), and if I am, it will only make a small > difference. (ex, the difference between 800+800gph vs 800+2000gph... > assuming 75% efficiency that's 1200gph vs 2100gph). > > So with that 1.5" hole I'd take on net water of ~42.5 gpm vs 25.8 gpm. So > whether 42 gallons per minute are coming in, or 25 gallons per minute, I > still need to plug it really friggin quickly. > > I do have the StaPlug btw, and Stay Afloat putty. > Just having a hard time imagining scenarios where an 800+2000 would make a > critical difference vs an 800+800, and wondering if this is just one of those > things where boaters are a bit paranoid and choosing the "bigger is better" > approach when that's not necessarily true. From what I can tell, *broken* > bilge pumps are the biggest issue (clogged, burnt out, bad wiring, etc). > > >> On Thu, Apr 14, 2016 at 1:22 PM, <cnc-list-requ...@cnc-list.com> wrote: >> From: Josh Muckley <muckl...@gmail.com> >> To: "C&C List" <cnc-list@cnc-list.com> >> Cc: >> Date: Thu, 14 Apr 2016 16:21:23 -0400 >> Subject: Re: Stus-List Bilge pump capacity? >> You'll have a shockingly hard time keeping up with a 1.5 inch hole no matter >> what size bilge pump you have. Plugging the hole is always better. Its >> gonna sink if the seacock disintegrates while you're not there. >> >> Josh Muckley >> S/V Sea Hawk >> 1989 C&C 37+ >> Solomons, MD >> > > > _______________________________________________ > > This list is supported by the generous donations of our members. If you like > what we do, please help us pay for our costs by donating. All Contributions > are greatly appreciated!
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