is this a pump

[Zingbri]

Hi
It’s been a long time since I posted on this forum but I have a question and photo to which I hope to find an answer and will appreciate any help. I have a Diesel trawler, Roughwater 35, ‘74 vintage. The photo shows what I think is some type of pump however it only has one opening. It is located inside a fixed bench seat (cushion support is removed). A 1 1/2” dia. hose connects to the opening and goes through the floor to the engine compartment Where it appears to go to a through hull. I say “appears to” because my genset blocks my view. There is a below- the-waterline through hull in line with the hose which I can see/feel on the outside of the hull. Does someone know what it is and what purpose it serves?
Thanks
Brian

[Warby12]

Sure looks like a diaphragm pump. Can you feel any inlet around the base? Not sure why you would want to drain that compartment though.Or maybe the inlet goes directly down from the diaphragm (I guess you checked that).

[Lepke]

It's a common pump on commercial fishing vessels. Usually there is a 4' to 5' steel round bar pump handle. These pumps move a lot of water.

[NYSail]

An emergency hand pump.

[Stewie12]

Diaphragm pump

https://i.ebayimg.com/images/g/L~IAA...iAz/s-l400.jpg

[roland stockham]

I suggest that the visible connection is the inlet so there is probably a strum box in the engine bay. I say that because the angled connector in the picture looks like a choker valve so would be on the inlet side. You need to find the other connection. Also with old diaphragm pumps the main diaphragm can deteriorate and split plus the internal rubber flap valve get stiff and stop sealing. Would suggest you get it out and do a full service before relying on it. But worth doing, a decent sized hand pump is a valuable safety feature.

[Zingbri]

Many thanks gentlemen! You have all been very helpful. With Warby 12 suggesting a diaphragm pump I researched and found an Edson pump model 638BR which looks just like it. Roland’s mention of a strum box was helpful too as I now understand how it works. The inlet is underneath but as yet I cannot find the Inlet hose which should lead to the pump. Will investigate today and let you all know.

[Cadence]

Originally Posted by Lepke

It's a common pump on commercial fishing vessels. Usually there is a 4' to 5' steel round bar pump handle. These pumps move a lot of water.

You may have hit on something? I was wondering about, what looked like, a lug wrench laying next to it. A handle?

[SV__Grace]

It looks like a manual bilge pump. The lug wrench is obviously the handle. Look for a hose in the bilge or someplace else (sump, cockpit, etc) that water would need to be pumped overboard and trace the hose.

[Brewgyver]

If it's the 638BR, then the visible hose is the discharge, the inlet is on the bottom side of the pump and not necessarily have an inlet hose connection.
https://www.edsonpumps.com/content/638BR-07.pdf

[TrentePieds]

Yes , Brewgyver has it absolutely right, and his diagrams show you just exactly where the "Johnson bar" goes.

It is an "emergency, backup" bilge pump you have available if the deeky little rule pump in your bilge becomes overwhelmed. The Edson pump as someone said, can remove "a lot" of water. Though only as long as you man the Johnson bar and don't weaken.

As your pump is mounted, it wouldn't come into play until a lot of water damage had done, methinks. You can fit a hose from the underside of the pump leading to a low point in the bilge. I think the intake 'ole on the underside is threaded for a nipple for the purpose. I have such a pump too, though it's a "Whale". They are conversation pieces rather than useful bilge pumps IMO.

TrentePieds

[Zingbri]

Hi, Brian here, re. the pump,
Managed to find the inlet today....a tiny stub of hose visible between the deck beams when I squeezed under between the Lehman and hot water tank.
As Roland said it was likely connected to a hose which had a strum box. For now I don’t plan on connecting a hose and strum box to the pump.
Thanks to all for your prompt replies and suggestions. 👍

[Lepke]

Originally Posted by Cadence

You may have hit on something? I was wondering about, what looked like, a lug wrench laying next to it. A handle?

I figure they were using the lug wrench. But a long handle makes it easier and lets you pump indefinitely.