Re: RE: [bolger] Bilge Pumps

David,

You must be talking about the page Dave Carnel put out a year or so ago
called "A Simple Bilge Pump." It's at mims.com/maib/bilgepump.htm.

ED HAILE

> I remember seeing a do it yourself bilge pump (piston type) that
>could be built using pvc pipe, neoprene or leather, washers, and
>other common hardware store items. I always felt that the common
>piston types were quite wimpy for the average user. If the pipe were
>enlarged and the handle of sufficient strength it should be possible
>to move a lot of water in a hurry.
> Does anyone remember which publication it was in? MAIB, Small
>Boat Journal, Wooden't Float?
>
>David Jost. Boston
>

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Tim Fatchen wrote:

>
>
> ...and there was one in Australian Amateur BoatBuilder by that ratbag
> Tim Fatchen, but that was years ago (1993?) and updated a 1940s
> Popular Mechanics design.

Australian Amateur Boatbuilder? Is it any good? Could I get an address
digital or other wise so that I might obtain a sample.

Have you tried our (as in USA) Boatbuilder?boatbuilder@.... I
always get something new out of every issue.

HJ

_ _ _ _ _
% Harrywelshman@...

--- Inbolger@egroups.com, jkohnen@e... wrote:

> Might have been MAIB. An article (possibly the same one) by Dave

Carnell

> can be found here:
>
>http://mims.com/maib/bilgepump.htm
> Simple Bilge Pumps From PVC

...and there was one in Australian Amateur BoatBuilder by that ratbag
Tim Fatchen, but that was years ago (1993?) and updated a 1940s
Popular Mechanics design. I'll see if I can locate the original
artwork for scanning and posting. An example of such a pump in
operation is onhttp://www.ace.net.au/schooner/lssurf.htm

Tim & Flying Tadpole

Light Schooner Website/Bolger boats in the Web/SquareBoats!
http://www.ace.net.au/schooner

Might have been MAIB. An article (possibly the same one) by Dave Carnell
can be found here:

http://mims.com/maib/bilgepump.htm
Simple Bilge Pumps From PVC

On Fri, 19 May 2000 00:56:27 -0000, David Jost wrote:
> hmmm. this is food for thought.
> I remember seeing a do it yourself bilge pump (piston type) that
> could be built using pvc pipe, neoprene or leather, washers, and
> other common hardware store items. I always felt that the common
> piston types were quite wimpy for the average user. If the pipe were
> enlarged and the handle of sufficient strength it should be possible
> to move a lot of water in a hurry.
> I agree with your other points about limiting cockpit size to
> begin with.
> Does anyone remember which publication it was in? MAIB, Small
> Boat Journal, Wooden't Float?


--
John <jkohnen@...>
http://www.boat-links.com/
The trouble with the school of experience
is that the graduates are too old to go to work. <Henry Ford>

I'm glad Peter said that... The story goes over here (I'm sure you heard it
before) that a famous yacht designer was asked what kind of bailing system is
the most effective and he replied, "A frightened yachtsman and a bucket.."
There were some tests done recently on behalf of Practical Boat Owner ( an
excellent UK magazine) - www.pbo.co.uk which had some interesting results. In
my opinion there was not conclusive proof for small boats that a man with a
bucket would be the worse option!!
My Micro will carry a couple of strong buckets and a small handheld pump to
drain the areas a bucket cannot reach.
I have tweaked the design to reduce the risk of swamping. My cockpit is sealed
off from the cabin (similar to a "normal yacht") and I do not have an engine
well. The cockpit has fairly hefty cockpit drains. Similarly my fo'ard
compartment is sealed from the top apart from a small anchor well.

> 70 litres/minute is equivalent to 1.2 litres/sec, 1.2

kilograms/sec, 11.5

> newtons/sec. If this water is lifted one metre from the bottom of

the boat

> and over the gunwale the power supplied (assuming no losses) is

only 11.5

> watts.

For those of us who are not engineers, how does this compare to
bailing with a 5-gal bucket?

If you think about designing a simple pump to the desired size, the
ship's bucket must be a limiting case with a 5 gal lift mechanism and
no enclosing pipe.

Peter

At 13:30 19/05/00 -0000, you wrote:

>
>> 70 litres/minute is equivalent to 1.2 litres/sec, 1.2
>kilograms/sec, 11.5
>> newtons/sec. If this water is lifted one metre from the bottom of
>the boat
>> and over the gunwale the power supplied (assuming no losses) is
>only 11.5
>> watts.
>
>For those of us who are not engineers, how does this compare to
>bailing with a 5-gal bucket?
>
>If you think about designing a simple pump to the desired size, the
>ship's bucket must be a limiting case with a 5 gal lift mechanism and
>no enclosing pipe.

What sort of gallon? How fast can you fill and lift it?

Roger.

I think I have a post on the subject from this group or another SOMEWHERE
(just installed another hard drive and moved some archives, but that's
another (happy) story...). I'll snoop around.

Don Hodges
dhodges@...
http://www.ecoastlife.com
Your Cyber-Vacation - Loafing on the Emerald Coast
Small Boats, Building, Fishing, Paddling, Rowing, Sailing

----- Original Message -----
From: David Jost <djost@...>
To: <bolger@egroups.com>
Sent: Thursday, May 18, 2000 7:56 PM
Subject: Re: RE: [bolger] Bilge Pumps


> hmmm. this is food for thought.
> I remember seeing a do it yourself bilge pump (piston type) that
> could be built using pvc pipe, neoprene or leather, washers, and
> other common hardware store items. I always felt that the common
> piston types were quite wimpy for the average user. If the pipe were
> enlarged and the handle of sufficient strength it should be possible
> to move a lot of water in a hurry.
> I agree with your other points about limiting cockpit size to
> begin with.
> Does anyone remember which publication it was in? MAIB, Small
> Boat Journal, Wooden't Float?
>
> David Jost. Boston
>
>
> ------------------------------------------------------------------------
> *--- FREE VOICEMAIL FOR YOUR HOME PHONE! ---*
> With eVoice Now you can keep in touch with clients, vendors, co-workers,
> friends and family ANYTIME, ANYWHERE. Sign Up Today for FREE!
>http://click.egroups.com/1/3426/10/_/3457/_/958697795/
> ------------------------------------------------------------------------
>
>
>

This is on Dave Carnells Site - URL Attached

> I remember seeing a do it yourself bilge pump (piston type) that
> could be built using pvc pipe, neoprene or leather, washers, and
> other common hardware store items.
>

At 00:56 19/05/00 -0000, you wrote:

>hmmm. this is food for thought.
> I remember seeing a do it yourself bilge pump (piston type) that
>could be built using pvc pipe, neoprene or leather, washers, and
>other common hardware store items. I always felt that the common
>piston types were quite wimpy for the average user. If the pipe were
>enlarged and the handle of sufficient strength it should be possible
>to move a lot of water in a hurry.
> I agree with your other points about limiting cockpit size to
>begin with.

It might be possible to construct a long stroke piston pump from 150mm or
200mm uPVC. The cylinder could lie flat in the bottom of the boat with the
plunger operated with a long vertical lever. It would need two valves, one
inflow and one outflow. There are uPVC one-way valves. Those that I have
seen are 50mm but there may be larger ones. The plunger part would not be
too difficult to construct, but it would need a bit of imagination to design
the lever part. The uPVC bits would not be cheap though. Maybe a large
homemade diaphragm pump is the way to go. Build it into the bottom of the boat.

Roger.

>The old vortex lifeboat pumps were centrifugal and had a 12:1 step up gear
>ratio. These were very high capacity but had two faults; they were
>ergonomically poor, and they resided in the bilge, so all the mechanism was
>"down there". This meant it had to be all bronze(they were hellish
>expensive), and if it blocked it was a bugger to get at to clear.
>
>My thoughts tend towards a modernised version of these pumps which would
>address the above faults.
>
>The pump and mechanism needs to be a deck level and it need to be operated
>like a coffee grinder winch.

Centrifugal pumps, at one extreme are axial flow, or at the other extreme
radial flow.
Most lie between these extremes. They are a mixture of axial and radial
flow. Radial flow pumps tend to be high head and low flow whereas axial
flow pumps are low head and high flow. A boat pump should tend towards the
axial flow type. They need to be submerged or at least have a foot valve
which will keep the pump full. In other words they are not self-priming. I
don't want to have to prime a pump when I have a ton of water in the boat!

Roger

hmmm. this is food for thought.
I remember seeing a do it yourself bilge pump (piston type) that
could be built using pvc pipe, neoprene or leather, washers, and
other common hardware store items. I always felt that the common
piston types were quite wimpy for the average user. If the pipe were
enlarged and the handle of sufficient strength it should be possible
to move a lot of water in a hurry.
I agree with your other points about limiting cockpit size to
begin with.
Does anyone remember which publication it was in? MAIB, Small
Boat Journal, Wooden't Float?

David Jost. Boston

>
> 70 litres/minute is equivalent to 1.2 litres/sec, 1.2
> kilograms/sec, 11.5
> newtons/sec. If this water is lifted one metre from the
> bottom of the boat
> and over the gunwale the power supplied (assuming no losses)
> is only 11.5
> watts. Not very much is it?

My point exactly - a human bean can generate a sustained 100 - 150 watts so
why can't we take advantage of it. I take the points about cockpit design
etc and agree that these should be optimised.

> single stage
> centrifugal pump could lift the water but the smaller the diameter the
> faster it must be spun. Without doing any calculations I
> suspect that the
> diameter would be excessive if it should be rotated by hand
> without gearing.
> Also centrifugal pumps must be made to close tolerances which
> adds to the
> price.

The old vortex lifeboat pumps were centrifugal and had a 12:1 step up gear
ratio. These were very high capacity but had two faults; they were
ergonomically poor, and they resided in the bilge, so all the mechanism was
"down there". This meant it had to be all bronze(they were hellish
expensive), and if it blocked it was a bugger to get at to clear.

My thoughts tend towards a modernised version of these pumps which would
address the above faults.

The pump and mechanism needs to be a deck level and it need to be operated
like a coffee grinder winch.

Foster

>Most of our small boats are equiped with a single-action diaphagm type
>bilge pump that will enable a fit person to shift about 18 US/15 Imp
>Gallons/70l per minute. Thats enough capacity to get the
>rainwater/spray/and odd "dollops" out but is less than desirable when faced
>with 1-2 cubic meters of water that a knock-down or pooping will present.
>The double-action pumps that are avaliable have the limitations of the
>action required to drive them and don't result in a big increase in
>capacity.
>
>The saving grace of the diaphragm bilge pump is it's simplicity,
>reliability, ease of maintenance, ability to cope with foreign matter, self
>priming and low cost (relative).

>I think the time has come to rethink the basic principles behind manual
>bilge pumps and see if there isn't now a more suitable type of manual pump.
>Some possiblities :
>
>- peristatic
>- diaphragm with better actuating mechanism
>- self priming centrifical

70 litres/minute is equivalent to 1.2 litres/sec, 1.2 kilograms/sec, 11.5
newtons/sec. If this water is lifted one metre from the bottom of the boat
and over the gunwale the power supplied (assuming no losses) is only 11.5
watts. Not very much is it? A quick look at a pipe flow chart using the
Lamont formula suggests to me that a pipe size in the range 100 to 150 mm is
required for this flow if the friction is to be kept within reasonable
bounds. My feeling is that pumps and pipes would have to be very much
larger in order to substantially increase the flow rate. A single stage
centrifugal pump could lift the water but the smaller the diameter the
faster it must be spun. Without doing any calculations I suspect that the
diameter would be excessive if it should be rotated by hand without gearing.
Also centrifugal pumps must be made to close tolerances which adds to the
price. Perhaps it is prudent to limit the cockpit volume which can be
instantaneously flooded and fit a couple of venturi type self draining
devices in addition to the diaphragm pump.

Roger