Gardner 6LW Fresh Water Cooling

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Steve.Sharratt

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Hi,

I have the subject engine in a Dutch Barge and currently cool engine and gearbox using raw water through a closed system. As I am on freh water, the system is, in principle, ok BUT - I have had uncountable blockages this year causing overheating and much stress. The blockages are not in the strainer but (i suspect) are plactic bags etc blocking the intake at the hull. My water twoer is unfortunately below the waterline (design issue) so I have to enter the engine room, cut the water supply off, remove the cap, to get water flowing again. All while drifting downstream. I would love to install an internal fresh water system (as a friend has on his barge) but I am struggling to find any information online. Not knowing exactly what the system is called doesn't help. Anyone with past experience out there? (I don't want to go down the keel cooling path.)

Cheers

Steve
 
I'm not sure that I understand 'internal fresh water system'. Engines create a great deal of unwanted heat, which has to be removed somehow. If not raw water directly cooled most engines will be indirectly cooled via a heat exchanger, which itself is cooled by water drawn in from outside the boat. This does not seem to solve your particular problem. The only alternative would be a fan cooled radiator, highly inconvenient on a boat.

I suggest that if your problem is due to blockage at the water inlet you could consider its design and location. I doubt if commercial barges suffer this type of problem, so there must be a common solution somewhere.
 
I understand that many steel canal boats use keel cooling, to avoid the problems of blockages you describe. Beta's canal boat engines are certainly cooled this way:
http://betamarine.co.uk/wp-content/uploads/downloads/operators_manuals/1940-3060-KC-IOM-0316.pdf
I think this may be what you are referring to. Possibly a phone call to Beta to see if will supply the necessary parts for your engine, assuming your boat is steel hulled. If it's wood or grp, I'm guessing keel cooling won't be effective.
 
Had a lot of this in a previous life with ships navigating rivers in West Africa. Fit a port and starboard inlet, quick changeover to keep you going then unblock strum box at leisure.
 
Kwik Decision said:
I understand that many steel canal boats use keel cooling, to avoid the problems of blockages you describe. Beta's canal boat engines are certainly cooled this way:
http://betamarine.co.uk/wp-content/uploads/downloads/operators_manuals/1940-3060-KC-IOM-0316.pdf
I think this may be what you are referring to. Possibly a phone call to Beta to see if will supply the necessary parts for your engine, assuming your boat is steel hulled. If it's wood or grp, I'm guessing keel cooling won't be effective.
Click to expand...

If you use external pipes the hull material is immaterial but you have the danger of damage occurring
 
the canal boat I hired had a section of double skin, i.e a box about 2 in thick on the inside of the hull, cooling an Isuzu 42hp, which had a heat exchanger, so indirect fresh water cooling. Lot of work to retro-fit, and surface area would be critical. You can doubtless buy heat exchangers and raw water pump for the engine, but no point really, just a little more leeway before a blockage overheats the engine. Is keel cooling a real no-no? Only needs a limited number of skin fittings.
 
As fisherman says if you don't want a keel cooler then you need a water tank built into the bottom of the boat with sufficient capacity to cool the engine. Suggest retrofit would be a massive job.

You can get above the waterline water strainers and if you mount it immediately above your seacock you can rod through without turning the valve off. Good idea to have two intakes in different positions and a a changeover valve, so if one blocks you can instantly change to the other.
 
I agree with all of the above comments about a heat exchanger simply transferring the blockage problems to another place, and think that fitting an auxiliary suction and strainer would be a possibility which would help.
However, in what is presumably a steel hull, the most sensible method of cooling would be by keel cooling. In our small jack-up barges the 350 hp Detroit two strokes keel coolers are simply approximately 10 to 15 feet long sections of 6 x 2 channel welded to the inside of the hull plating with a couple of flanged nipples welded at the ends and then connected to the engines suction and return lines. The engine cooling water treatment prevents internal corrosion, and as a matter of interest there is actually enough radiation cooling capacity to allow the engines to run for about 1/2 hour while we elevate the hull clear of the water... when the e ngines are working at full load!
 
the ancient engine (1908 Hornsby) which powers our ancient winch for the beach boats is cooled by a simple open topped tank. Suppose you installed a copper household indirect cylinder and pump river water through the coil. The capacity would keep you going through any clearing requirements.
 
fisherman said:
the ancient engine (1908 Hornsby) which powers our ancient winch for the beach boats is cooled by a simple open topped tank. Suppose you installed a copper household indirect cylinder and pump river water through the coil. The capacity would keep you going through any clearing requirements.
Click to expand...

Or as well as piping through an indirect cylinder, install some central heating radiators in the engine cooling circuit. You can calculate the heat absorbed from the radiator's btu or kw rating. Eg if the engine was 50% efficient and produced 20kw underway, 3x 3kw radiators may be adequate. Experimentation required!
 
The Gardner is rated at 120hp, so probably cruises using about half that. So very different from an old stationary donkey engine. Not sure having to heat the boat to cool the engine is a good idea!
 
Tranona said:
Not sure having to heat the boat to cool the engine is a good idea!
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Its a brilliant idea, you're just jealous because you didn't think of it first...

(well it would work well for 9months of the year and its a pity to dump the waste heat overboard!)
 
ianj99 said:
Its a brilliant idea, you're just jealous because you didn't think of it first...

(well it would work well for 9months of the year and its a pity to dump the waste heat overboard!)
Click to expand...

You can say that about any engine in a boat - but seems we find it easier to use the water that the boat is floating in to cool the engine and return the water after it has been used. Even those who do use hot water to heat their boats don't use the engine for the job.
 
Tranona said:
You can say that about any engine in a boat - but seems we find it easier to use the water that the boat is floating in to cool the engine and return the water after it has been used. Even those who do use hot water to heat their boats don't use the engine for the job.
Click to expand...

That's not to say it won't work, not that I was being entirely serious just thinking outside the box..

I gather the barge is on an inland waterway, so the engine requirement is not as demanding and there is probably much more room for the radiators compared to a sea going vessel.
 
I did immediately think of radiators as well as a copper cylinder, but I would hazard a guess that the indirect coil, and you can get cylinders with two coils, would be enough. Got to be the same surface area of cold pipework as a heat exchanger, plus the huge capacity would be a buffer.
 
Thanks to everyone for your helpful comments - some good ideas to ponder. I just had another blockage today (caused through grass-cutting along the canal) so I am just about over raw water cooling. I know many people love keel cooling but I worry about exposed pipes when I am bouncing of a shallow section of canal. BTW my boat is a steel 24m 1922 Beurtschip originally used as a day-trader in Holland. I have tracked down what I would like but the information is a bit sparse so I have gone back to the manufacturer for clarification. FYI link is attached https://www.bloklandnonferro.nl/en/products/cooling/bottomtype-coolers/ . They way I understand it, it is basically keel cooling but is on the inside of the hull. The trick will be to find a place that will fit a 1m x 200m box directly to the hull.
 
That seems to be basically a tubestack inside a tank which is open to the raw water, which has a heat sink close to the hull, so the heat transfers from the engine water to the raw water via the tubestack, then from the raw water to the hull. You still need another hole in the side of the hull. If you are going to make new holes in the hull then there are other possibilities. Begs the question could you DIY......I wonder if there is a heat conductive paste which could be used to bed a grid of small flexible copper pipes to the inside of the hull. (here are some, http://www.masterbond.com/propertie...zEfTOWT2AjLKqkkf7S9nkNbGzoUluGQrRHxoCacPw_wcB)
A friend once achieved emergency cooling for a hydraulic circuit by merely allowing the pipes to lay in the bilge water.
 
I agree with your observations Fisherman. If I am still required to use raw water I can't see how this will add any benefit as my current system is doing all of this without the need for a large box. My aim is to eliminate the need for raw water due to frequent blockages I have suffered. I have also been pondering whether an internal system could be home-made. Ultimately (I guess) it is just a matter of sufficient water in the circuit to ensure that by the time it comes around for another turn at cooling the engine it has cooled sufficiently that it is still effective. The volume will be dictated by how efficiently you can cool the recycled water.
 
The system you have looked at is only open to, and not circulating, raw water. Is your engine near the stern? Does your boat have any keel at all, or just a flat bottom?
 
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