Raw water cooling - isolation valve (sea cock) ?

[DHutch]

Might be a simple question, but what do people normally use on the inlet on a rare water cooled engine, do they normally turn it off when leaving the boat?

 

I'm partially thinking under-deck engines, where it would be less easy than an engine room environment to have a procedure to open then valve before using the engine.

 

 

Daniel

[Titus]

We used to have a sea cock on our old Springer I only ever turned it off in winter or when the filter blocked and I had to clear it.

[mrsmelly]

Might be a simple question, but what do people normally use on the inlet on a rare water cooled engine, do they normally turn it off when leaving the boat?

 

I'm partially thinking under-deck engines, where it would be less easy than an engine room environment to have a procedure to open then valve before using the engine.

 

 

Daniel

 

I can only quote profesionaly not leisure in that we always turned off all valves after every sail to the strums. It will depend realy just how much water would be taken on board in the evnt of a leak if I would bother in the situation you mean and every instalation would be different.

 

Tim

[Guest]

Our previous boat had a failry standard gate type BSP threaded valve on the raw water inlet. I only used to close it if leaving the boat for a particularly long period, or over winter.

[David Mack]

Fulbourne is cooled with very ordinary canal water. We have the original seacocks - two, one at high level and one at low level and both connected to a single mud box. We use the upper one only. Generally left open for the duration of the trip when we are boating, but turned off when the boat is left for any length of time. We also drain the engine when freezing is possible.

[Mac of Cygnet]

I always close mine when I leave the boat for more than a day or so, not inconvenient as I turn off the battery isolators at the same time, just beside the seacock.

 

BUT if anyone else is using the boat, MAKE SURE A PROMINENT NOTICE IS DISPLAYED reminding to open the seacock!

[Graham.m]

Might be a simple question, but what do people normally use on the inlet on a rare water cooled engine, do they normally turn it off when leaving the boat?

 

I'm partially thinking under-deck engines, where it would be less easy than an engine room environment to have a procedure to open then valve before using the engine.

 

 

Daniel

 

I suggest it is good practice to turn it off when leaving the boat for any period of time and put a label on the control panel that t is turned off. You don't know when that pipe will fail nor how much water it will let into the boat.

 

If leaving for winter I would suggest turning off the the stop cock opening the filter and while turning the engine over introduce 50% antifreeze until its the engine drain show the antifreeze is though the engine. This is particularly important if the boat has a gas/water separator.

Edited December 31, 2015 by Graham.m

[Southern Star]

Something I've wondered, and I'll ask it here rather than clogging up the forum with a dedicated thread.

 

What is the advantage of raw water cooling compared to using a skin tank? To me, it seems fraught with potential problems to use canal water to cool an engine as opposed to water in a captive circuit, but I accept that there will be reasons why this is done (and that I just don't understand yet). What are the advantages of raw-water cooling?

[Guest]

Something I've wondered, and I'll ask it here rather than clogging up the forum with a dedicated thread.

 

What is the advantage of raw water cooling compared to using a skin tank? To me, it seems fraught with potential problems to use canal water to cool an engine as opposed to water in a captive circuit, but I accept that there will be reasons why this is done (and that I just don't understand yet). What are the advantages of raw-water cooling?

Our previous boat was raw water cooled and was fine. The big advantage was that you weren't concerned about whether the skin tank was big enough (often they aren't.) There are two distinct types of raw water cooling; direct and indirect, ours was direct which is simplest, the only likely causes of problems were if the actual water pump failed, or the inlet got blocked.

Disadvantages were near impossible to heat water from enigne, pain in winter getting antifreeze in there, can block mud tank/inlet.

Overall I have grown to prefer the skin tank on the current boat, but would never rule a raw water cooled boat out.

Edited December 31, 2015 by Guest

[David Mack]

What is the advantage of raw water cooling compared to using a skin tank? To me, it seems fraught with potential problems to use canal water to cool an engine as opposed to water in a captive circuit, but I accept that there will be reasons why this is done (and that I just don't understand yet). What are the advantages of raw-water cooling?

 

For your average modern welded steel narrow boat, probably none. But skin cooling isn't an option on wooden craft and probably less suitable for riveted boats.

 

Before skin cooling there was keel cooling, where a pipe carrying engine coolant ran round the outside of the hull. But a pipe has a limited surface area compared with a skin tank, so quite a long length is needed to give the same degree of cooling, and it is much more vulnerable to damage. In contrast raw water cooling gives you a limitless source of cooling, whereas a number of skin-cooled narrowboats are OK pottering on the canals, but suffer from overheating when run harder on rivers.

[koukouvagia]

I always turn off the seacock when I leave the boat. I like to use it frequently so that it doesn't seize up.

 

Raw water cooled engines like the Kelvin were first put into wooden fishing boats, long before skin tanks were invented.

 

You also don't need a temperature gauge. As long as you can see water being pumped out the side of the boat, you know that nothing is overheating.

Edited December 31, 2015 by koukouvagia

[Neil Smith]

When I had a lumpy water boat with a 250hp perkins turbo it just had a 2" brass gate valve from the plumbers but one cold rainy day while getting the batteries out I stepped on the pipe and without knowing started it leaking, 2 days later partially submerged boat so I always turned it off after that.

 

Neil

[FadeToScarlet]

On my previous boat, I only used to turn off the seacock if leaving the boat for more than a couple of days, as it meant clearing out a cupboard, lifting the bottom of it, and going headfirst down it alongside the engine to reach it. A bit of poor design, if I had a boat with a better design I'd ensure it was much more accessible. Then I had a skin tank put on which solved all that faff.

 

On the Bantam tug I look after, the seacock is left shut and the valves on all other through-hull fittings too, with prominent notices to open them all before running the engine.

 

On the trip boat, they're left open all the time, which I wouldn't do if I were running the business.

[Alan de Enfield]

Lumpy water training - presumably you have a tapered wooden bung loosely attached to every thru-hull fitting ?

 

[DHutch]

Seems genuinely accepted not to always use it then.

 

I just wondered. We have one on EmilyAnne, which is turned off every evening at the end of using the engine. But its in an engine room, and we are already turning on/off around eight other valves minimum. We also have fairly good rubber hose to the pump, and the rest of the loop is fairly closed before exiting above the waterline, so even if the valve where open we shouldnt really ever sink.

 

What sort of things do people use for inline filters?

 

 

Daniel

[David Mack]

What sort of things do people use for inline filters?

 

We have the original cast iron mudbox, which has a removable perforated plate across the middle. This would stop big stuff getting into the engine, but we were often plagued with leaf and twig litter passing through (especially in Autumn) and stopping the valves in the (reciprocating) water pump from closing. If you were on the ball you would notice the lack of water from the outlet. But if not, the giveaway was clouds of steam appearing as the water in the engine boiled!

 

All solved by putting a number of pads of pond filter foam in the mud box, which traps all the small stuff. As these clog the water flow reduces over a period of time, giving you the opportunity to open up the mudbox, rinse out the foam and remove any mud at a convenient time.

[OldGoat]

In reality - I suppose it's how the whole arrangement 'works'.

Knowing nothing (better) when I built - I put a seacock on the fitting provided by the builder feeding to a Vetus filter mounted above the waterline - so there's not a lot of point in turning off the valve in normal circumstances - as there's not much chance of water entering the boat.

 

I used to flush a mix of antifreeze through the heat exchanger - in fear of harsh weather, but as a member of another forum pointed out, the water temperature in his marina never fell below 4 degrees - even when the ground was frozen (a few years ago - mind), so I don't bother now.

 

Again - it all depends on an individual boat's configuration.

[Graham.m]

Seems genuinely accepted not to always use it then.

 

I just wondered. We have one on EmilyAnne, which is turned off every evening at the end of using the engine. But its in an engine room, and we are already turning on/off around eight other valves minimum.

 

What sort of things do people use for inline filters?

 

 

Daniel

 

This is commonly used on generators and the like

 

 

Edited December 31, 2015 by Graham.m

[Neil Smith]

Lumpy water training - presumably you have a tapered wooden bung loosely attached to every thru-hull fitting ?

 

they look like the pegs I use in my beer firkins use them to peg my beer firkins LOL.

 

Neil

 

 

[Giant]

Our Sheffield size keel has a raw water cooled JP3M in its original installation. Only a single seacock at low level, but the cooling supply could be switched over to be taken instead from the roughly 4 ton ballast tank at the aft end of the engine room. Not really a skin tank, as it would have been mostly above the waterline unless heavily loaded, but the sheer size of it would probably have allowed for extended running. The tank is rusted through now and we might remove it to gain some space, although I'm also tempted to restore it as an aid to getting under low bridges.

 

The mudbox is quite large, about 6-8 inches across and at least the same deep, with a perforated metal sheet installed vertically. We've never had any blockage but we've been almost exclusively in tidal waters since we got the boat. The previous owner reported trouble with duckweed getting through on the canals.

 

We always close both the seacock and fuel supply as soon as we're done with the engine for the day. We do have a collection of wooden bungs but there is not in fact one tied next to the seacock. That's a good idea which I think we'll implement.

[tidal]

I've always closed all seacocks when leaving a boat for more than a couple of hours.
And yes I always had wooden plugs handy/next to the cocks.

 

The most worrying thing I have read on here is that some aren't easily accessible?
Having had one fail in the past and having had pipes to them fail that concerns me

[GUMPY]

Just been and checked mine, despite me normally closing it, I hadn't..........been like that for six months ;(

[tidal]

Most of the ones I have come across are single lever types and if they didn't have a hole in the handle I drilled one.

Then I got some short lengths of metal rod drilled the ends of them and put a keyring and tab on them. then when closed I push them through the hole in the handle
When the cock is open you have to remove them (I hang mine by the companion-way door) and glance at the board they fit on as I leave.
If they are on the board I swear at myself and go and close the cock and push the pin through .

 

It's probably OTT but for me it's a good memory aid

 

The same process works with the red-handled tap type gate valve versions

Edited January 8, 2016 by tidal