On Red Ranger, we use the 5F's of safety.
Fatigue and Famine
These help us separate what's safety critical from what's merely a good idea.
Which leads us to pumps. Hull integrity, hose integrity, and hose clamps are important preventative measures. A dripless shaft seal is a big deal, too. Pumps are a backup measure in case water gets in through some more devious route. The principle is simple: Water stays outside the boat.
Red Ranger had four working pumps when we bought her. Two were for the bilge, one waste, and one freshwater:
A big old Jabsco diaphragm pump for the bilge and desk wash down. This is a 36900 that dates from 7/4/96.
A smaller (but similar) Jabsco diaphragm pump for freshwater. This is a 36950-2 that dates from 6/15/97.
A macerator pump to drain the holding tank when at least three miles off shore. This dates from June 2001.
A manual backup bilge pump that (presumably) dates from manufacture in 1982.
How do we know this?
Lots of previous owner paperwork.
Each installation manually neatly dated with the installation information.
The dates are potentially helpful. They might show that each pump lasted as long as 10 years. Since there are two spare 36950 bodies in the back, we have some doubts about the dates. Is the date from the most recent replacement of the four? Or is the date from the first replacement of the four?
When I divide 33 years by 3 pumps, that also says 10 years per pump. Sounds good. That's (at current prices) $2100 worth of pumps, or about $63 per year.
That means that the $140 replacement has to last three years to be worthy.
We didn't think two bilge pumps were enough.
One of the first big jobs I did was to add another electric pump to the bilge. See "A Manifold of Bilge Pumps." I added a Rule submersible pump. We used a higher float switch so that it's only used when the primary pump has failed or can't keep up.
This second automatic bilge pump is wired (via a fuse) directly to the battery. It cannot be switched off. Some sailors will wire an alarm horn into the backup bilge-pump circuit so that they know if it ever actually starts running.
We've also purchased a second manual bilge pump. This is a "hand bilge pump" that we use to pump the dinghy as well as the bilge.
We could use our freshwater transfer pump in an emergency, also. And the shower sump (see below) would also work.
Eventually, we replaced the big old diaphragm pump with a smaller, less expensive Jabsco PAR-max Plus "water pump." It's still a diaphragm pump inside the housing, but it's smaller, quieter and slightly easier to work with. It's nominally a "fresh water" pump, so we're taking a risk by using it on bilge water. But it's 50 PSI and has been very reliable. See "Week 5: Vacation."
I also split the bilge output into three separate openings to prevent the (remote) possibility of water running in circles through the "Y" fittings in the original one-and-only outlet. See "CA's Day Job."
I've also replaced the 2001-vintage macerator pump. This is a tricky thing to test because you can only use it off shore. I can't find the blog post with pictures. Maybe I didn't take very many pictures of this job. It's pretty boring: pump, hoses, wires. Blah.
I know that I was really excited about putting in a two-part switch: there's a circuit breaker that's now separate from the momentary on-off switch that actually powers the pump. Since the pump draws HUGE amount of current, the on-off switch trips a breaker that carries the current load for the pump. The two-switch setup makes it less likely that the pump is activated by accident.
We've used it once off shore to be sure it worked. Since we use our Nature's Head, the holding tank is generally empty. And since we're only weekenders now, neither gets used much.
Last weekend I replaced the freshwater pump (finally) with another PAR-max water pump. It's quieter and slightly simpler than the big old diaphragm pump. It's slightly lower volume, but higher pressure. We're delighted in it's first weekend of operation.
The original design for the showers had the water draining straight into the bilge. This can lead to stinky soapy water in the bilge. This is not a good idea. I added a sump pump to the forward head to pump shower water straight overboard. This is a Whale Gulper specifically built to handle shower water including hair and other detritus. See "Week 2: Final Preparation" for details.
The aft head — if we ever used the shower there — still drains straight into the bilge.
We've moved "up" from four pumps to eight pumps. Two electric bilge pumps, shower sump pump, freshwater pump, macerator pump, portable wash down pump, plus two manual pumps. This seems slightly more complex than what we had before.
Pumps — and pump failures — are an important part of boating. There's water out there, and it's supposed to stay out there. The overall idea is to improve safety through technology refresh and redundancy.