Bilge pump dilemma

[webcraft]

.#
My MG30 has a well or sump the size of a largish saucepan as the deepest part of the bilge. It is approximately 180mm in diameter and about the same depth.

Current bilge pump arrangements are one manual whale gusher with a 1.5" hose in this well.

I had hoped to fit an Orca 1100GPH fully automatic pump in this well, but it looks as though it will not fit. Although I could get it into the well (just) there would be no room to curve the hose from the outlet upwards.

Another option I had thought of is the manual 950GPH Orca model with a field sensor mounted alongside it. I believe there would just be room for this, though the sump would be pretty full of gear and so would fill up quickly in a seaway when water slopped out of the rest of the bilge into the sump. This would not be an issue when the boat was in a marina though, and the pump could be switched off auto on passage if this was an issue. Also, there is a model of the field sensor that waits 30 seconds before switching on to avoid over-switching in this situation, so maybe not an issue.

I want an auto pump as the boat may be left unattended in a marina for relatively long periods of time. I don't want it to cycle too much. Seaflo pumps would fit, as might a Rule-mate, but neither of these look particularly robust or have very good reviews. The linear Whale models don't fit either.

The Whale Orca pumps have very god reviews and the 950GPH model with a field sensor switch seems like the best option - anyone got any comments or suggestions?

- W

 

[Caer Urfa]

.#
My MG30 has a well or sump the size of a largish saucepan as the deepest part of the bilge. It is approximately 180mm in diameter and about the same depth.

Current bilge pump arrangements are one manual whale gusher with a 1.5" hose in this well.

I had hoped to fit an Orca 1100GPH fully automatic pump in this well, but it looks as though it will not fit. Although I could get it into the well (just) there would be no room to curve the hose from the outlet upwards.

Another option I had thought of is the manual 950GPH Orca model with a field sensor mounted alongside it. I believe there would just be room for this, though the sump would be pretty full of gear and so would fill up quickly in a seaway when water slopped out of the rest of the bilge into the sump. This would not be an issue when the boat was in a marina though, and the pump could be switched off auto on passage if this was an issue. Also, there is a model of the field sensor that waits 30 seconds before switching on to avoid over-switching in this situation, so maybe not an issue.

I want an auto pump as the boat may be left unattended in a marina for relatively long periods of time. I don't want it to cycle too much. Seaflo pumps would fit, as might a Rule-mate, but neither of these look particularly robust or have very good reviews. The linear Whale models don't fit either.

The Whale Orca pumps have very god reviews and the 950GPH model with a field sensor switch seems like the best option - anyone got any comments or suggestions?

- W

I had similar problems fitting a low level bilge pump right under my engine and also with limited space, looked at a few options and finally went for a Whale Supersub Smart 1100 (there is also a 750 version) it's automatic and works well and low with hose connection options.

 

[webcraft]

I had similar problems fitting a low level bilge pump right under my engine and also with limited space, looked at a few options and finally went for a Whale Supersub Smart 1100 (there is also a 750 version) it's automatic and works well and low with hose connection options.

Looks like a great pump, but too long for the diameter of the sump.

- W

 

[lw395]

How do you arrive at wanting a 1100GPH pump?
Fitting a small auto pump into a RIB, I found using 135degree overflow pipe bends much easier than curving a hose tightly enough. Without the resistance of using 90degree fittings.
Fairly small bore plumbing helps with the cycling issues.

Is this a 'smart' pump which works by spinning the pump every now and then to see if there's water, which it senses by the resistance?
AFAIK, they are unsuitable for running in a dry bilge. Great for a RIB, but in the dry bilge of a yacht, they will burn out the seal and stop working in a week or six.

 

[prv]

Our previous boat had a very deep, narrow bilge that went right down into the long keel under the cockpit. Rather than lower a centrifugal pump into the inaccessible depths, I used an electric diaphragm pump mounted in a locker with a hose reaching down into the bilge. Might this be an option?

Pete

 

[webcraft]

How do you arrive at wanting a 1100GPH pump?

Hole diameter 1 inch (eg seacock hose failure)
Depth below water line 12 inches
Water flow into the boat 2,700 Litres per hour

- so can probably get away with 900GPH, but 500GPH is too small as there are always losses from the manufacturer's figure. However, the 500GPH orca would definitely fit. Needs to be automatic though, so with a field sensor.

Fitting a small auto pump into a RIB, I found using 135degree overflow pipe bends much easier than curving a hose tightly enough. Without the resistance of using 90degree fittings. Fairly small bore plumbing helps with the cycling issues.


Not room because the sump is so small

Is this a 'smart' pump which works by spinning the pump every now and then to see if there's water, which it senses by the resistance?
AFAIK, they are unsuitable for running in a dry bilge. Great for a RIB, but in the dry bilge of a yacht, they will burn out the seal and stop working in a week or six.

It's a solid state detector

 

[lw395]

What is the statistical incidence of AWBs sinking in the marina?
How many have ever been saved by an auto bilge pump?
My experience of 12V bilge pumps is that you need to make big adjustments to the GPH figure for both head it's pumping against and length of hose it is pumping through.
Also the incidence of them blocking when unattended is quite high, even on open boats which are kept strictly free of loose 'stuff' as far as possible.

Yotties seem to think they must need these things because the chandleries are wedged full of them these days. They mostly came on the market for open deck fishing boats in the US, where they are very useful.
30 years ago, nobody had them and very few boats sank on their mooring then either. The odd wooden vessel tries from time to time of course.

You'd be better off spending the cash on making sure your skin fittings are beyond suspicion. And maybe a bilge alarm?

 

[Kelpie]

There's a difference between an 'everyday' bilge pump whose job is to cope with minor rainwater leaks, drips from the stern gland, or condensation etc, and an 'emergency' bilge pump which deals with a sudden failure.
The latter needn't be sited right down in the bilge- just stick it as low as you reasonably can. And consider linking it to an alarm to alert those nearby.

 

[SteveGorst]

I have used a whale gulper 220 mounted in a locker with a pipe down into the sump and an automatic switch in the sump to control it. I used an electronic switch but a standard float switch would do.

 

[yoda]

I have used a whale gulper 220 mounted in a locker with a pipe down into the sump and an automatic switch in the sump to control it. I used an electronic switch but a standard float switch would do.

I use a similar arrangement but have a whale sensor with built in time delay for switching off. I have the switch on a height adjustable mount (2 threaded bars) so that it starts the pump when the sump is half full and turns off after emptying it. This avoids frequent cycling of the pump when sailing with a small amount of water in the bilge.

Yoda

 

[neil1967]

How effective is the gulper in emptying the bilge, and do you get much flow back from the pipe into the bilge once the pump has switched off?

 

[webcraft]

I use a similar arrangement but have a whale sensor with built in time delay for switching off. I have the switch on a height adjustable mount (2 threaded bars) so that it starts the pump when the sump is half full and turns off after emptying it. This avoids frequent cycling of the pump when sailing with a small amount of water in the bilge.

Yoda

Have you had the whale sensor long? I have read a few criticisms of its reliability, but that is what I am planning to buy.

- W

 

[SteveGorst]

extremely effective and I use a one way valve to stop the flow back. The gulper will pump air and is self priming so it doesn't leave much water in the pipe anyway.

 

[prv]

Have you had the whale sensor long? I have read a few criticisms of its reliability, but that is what I am planning to buy.

I've had one installed a couple of years now. No apparent problem, but since the bilge is generally fairly dry it hasn't exactly been strenuously tested.

Certainly it doesn't run when it shouldn't, but I can't be quite so sure that it does run when it should

Pete

 

[Hydrozoan]

What is the statistical incidence of AWBs sinking in the marina?
How many have ever been saved by an auto bilge pump?
My experience of 12V bilge pumps is that you need to make big adjustments to the GPH figure for both head it's pumping against and length of hose it is pumping through.
Also the incidence of them blocking when unattended is quite high, even on open boats which are kept strictly free of loose 'stuff' as far as possible.

Yotties seem to think they must need these things because the chandleries are wedged full of them these days. They mostly came on the market for open deck fishing boats in the US, where they are very useful.
30 years ago, nobody had them and very few boats sank on their mooring then either. The odd wooden vessel tries from time to time of course.

You'd be better off spending the cash on making sure your skin fittings are beyond suspicion. And maybe a bilge alarm?

That’s as may be (as a colleague used to say, irritatingly ) but when we bought our boat 12 or so years ago it had only a manual bilge pump, and the surveyor recommended adding an automatic, and the insurer asked for the surveyor's recommendations to be followed ... so we have one. I suspect that many others may have them for a similar reason.

 

[webcraft]

That’s as may be (as a colleague used to say, irritatingly ) but when we bought our boat 12 or so years ago it had only a manual bilge pump, and the surveyor recommended adding an automatic, and the insurer asked for the surveyor's recommendations to be followed ... so we have one. I suspect that many others may have them for a similar reason.

We are planning to let this boat out on AirBnB occasionally, so it needs to be fairly idiot-proof. An auto bilge pump of some sort seems a no-brainer.

- W

 

[Hydrozoan]

I have just replaced our first, a Rule 1100 with separate float switch, after about a dozen years. The bilge is pretty dry, so it was not strenuously tested either but occasionally used on manual to remove non-oily rinsing water. It always seemed reliable, but eventually succumbed to sticking in some part of its anatomy. Being remote from the boat, I do take lw395's point that a bilge alarm - an external flashing light? - might be useful, if the marina staff were told what it meant.

 

[gregcope]

extremely effective and I use a one way valve to stop the flow back. The gulper will pump air and is self priming so it doesn't leave much water in the pipe anyway.

I have similar. With a water which switch. Apears to work well. Would do the same again.

 

[yoda]

Have you had the whale sensor long? I have read a few criticisms of its reliability, but that is what I am planning to buy.

- W

First sensor failed inside a year - keep your receipt! If mine fails again I will try to find an alternative.

Yoda

 

[NormanS]

We are planning to let this boat out on AirBnB occasionally, so it needs to be fairly idiot-proof. An auto bilge pump of some sort seems a no-brainer.

- W

That's as may be.

I've had boats on moorings now for nearly 60 years (I started young), and I've never had, or wished I had, an automatic bilge pump. My only personal experience of an automatic bilge pump was when the boat wintering next to mine in the Caley Canal developed a split in a fuel tank, and proceeded to pump 200 gallons of diesel into the canal. You don't win brownie points that way.