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Sinking?

3K views 16 replies 13 participants last post by  SVAuspicious 
#1 ·
Once again it has come to my attention that a vessel was lost due to an influx of water and insufficient pumping capability.
In this case I'm writing about the Bounty, (I just read; Life and Death on the Bounty) but just a few months ago a very good friend had his boat sink out from under him with both engines running full bore, heading for shallow water to beach the boat, almost costing him his life.
Bounty had two main engines and two 20 kw generators from what I understand. That's possibly four diesel engines running at full capacity and just exactly what is keeping those engines cool? Water!
If you ever find yourself in this situation, close the seacock (s) and take the intake hose (s) off the thru hull and drop it (them) in the bilge! There should be a sea strainer to catch debris which is very easy and quick to clean, unless you have sea chests, in which case a cloth or colander or even your fingers will minimize the clogging.
I'm not saying that in the case of the Bounty that it would have made a difference, but they may have had a better chance with less water in the engine room, and engines and generators running. It definitely would have made a difference (all the difference) in my friend's case.
On some boats I have even Y-ed the intake and carried enough hose to reach anywhere aboard.
Throwing a sail over a hole in the hull can give you enough time to get a mattress inside with something (a door, the table whatever) to push against the hole from the inside, further slowing the influx of water. Then, when the weather abates (if that's a problem) maybe you can arrange a more permanent solution and sail yourself back to safety.
Some friends of mine were holed by a log a thousand miles SW of Hawaii and after doing the above, sailed safely back to Honolulu, certainly not without problems, but again they lived AND saved the boat.
So in those unwanted moments of catastrophe, do not lose your head and your boat; think. There may be a simple, easy, if temporary, solution to your immediate problem.
 
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#2 ·
twp issues with using an engine's coolant pump as a bilge pump on a big old wooden boat:
1. You gotta be able to pump it out faster than it is coming in, and cooling pumps aren;t designed to move a big GPM number..
2. Ever seen the bilge in an old working wooden boat? Just dropping the intake hose in the bilge is inviting the pump itself to get snuffed. Now you have no pumps and no power.
3. Being holed by a log on a smallish modern fiberglass boat is a whole different level of ass-pucker than trying to keep up with the square rig, constantly leaking hull , excessive windage and just generally being outmanned and outgunned circumstances of slamming through a widefront hurricane in a cumbersome, slow-moving, ill-maneuvering replica ship.
 
#3 ·
Like bljones said.

Think about how much water comes out when your engine is running. On most boats it is basically a very small stream--almost a trickle. Certainly not even close to as much as a large bilge pump can flow.

Then, what if you clog your engine intake with crap from the bilge? Now you are in REALLY big trouble. You've just made your problems several times worse.

Of course, in dire circumstances, you do what you have to do. But I would rather make sure that my engine keeps running, and therefore will still be able to power my electric bilge pumps. I would only use the engine coolant intake as a bilge pump in the most extreme of circumstances.
 
#4 ·
there is a difference between the engine's waterpump and the raw water cooling (assuming your boat uses a split system)

IF you were to open the radiator on a car while it was cold and start the engine (I do not recommend doing this while the car is hot) you will see that the engine's waterpump can push a good amount of water. Maybe not as much as a good bilge pump, but it can.

The only reason the engine on a boat seems to move so little water is due to restrictors in the cooling intake. Unlike a car that has an air to water radiator (an inefficent design) that can see temps from -40 to well over a 100 ambiant.. a boat's cooling system typically only sees it's ambiant temps from around freezing to the upper 80s.. so you have to restrict the amount of water incoming to keep the engine from running TOO cool
 
#6 · (Edited)
I think the best thing you have to keep your boat from sinking is good plan and the stuff at hand to implement it.

The first part of my plan is having damage control gear on board. The point of damage control is not to repair but to slow the leak enough that your pumps can keep up until you can get the boat out of the water. (Thanks for all that training, USN!) Needless to say it works better on small boats that are coastal cruising or in protected waters than it does for blue water sailing.

We all have hammers and the wood plugs for seacocks, of course. For other holes, I bought one of those foam cones to stuff in them, If you can get to the leak and it is big, stuff anything at hand into it that fits -- T-shirts or underwear, your kid's pool weenie cut to size, whatever. I like foam stuff that you can compress then it expands to fit the hole. That works even for irregular hole shapes.

I have Rescue Tape to wrap around leaking fittings, hoses, and such.

I have a tarp with pre-rigged lines I can pull up tight against the hull to cover cracks or whatnot that the foam cone can't handle. Note to self -- don't cover engine cooling water intake (which means you have to know where it is) unless you absolutely have to! A tarp won't work near the keel since you can't pull it up tight against the hull, but it would slow a leak in the forward or aft part of the boat. I've debated keeping some butyl tape I could stuff in the crack before tarping it. I'm not sure how effective it would be without something to hold it in place (like the tarp, maybe).

Now the second part of my plan is thinking through how to find the leak quickly. It may not be obvious, so I will look at sea cocks and through hulls first, then hose clamps, then the hoses themselves. Of course, if you experienced a precipitating event you probably know the general area to search. If not, start at the bottom and work up (cause it is harder to figure it out underwater, and the water level starts on the bottom and rises).

Once you have the damage under control, you can see whether it is repairable at sea or whether you need to make a run for shore and the nearest travel lift.

So what do you do once the awful day comes?

1) Call the Coast Guard and let them know of your situation.

2) Get the damage under control. If you can't, get your ditch bag.

4) If you can, assess what's next -- repair, Towboat US, limp back home, Coast Guard, etc.

5) Call the Coast Guard again and update them.

6) Once you (and, one hopes, the boat) are back on terra firma, break out the boat bucks.

So that's my plan. What's yours?

Tom
 
#7 ·
One inch hole, 4 feet below water line = 40 gallons per MINUTE (2400 per hour)
(a through hull) or small log
2 inch hole, 2 feet below water line = 111 gallons per minute
(a rudder stock, or bigger log)

Chart for Determining Flow of Water Through Holes in Gallons Per Minute

Add the additional depth below water line that weight of water will cause, it becomes a losing battle quickly.

Your time (what little you have) is better spent stopping of reducing the flow - not disconnecting engine hoses and leading them to the bilge.
The Navy teaches it that way - stop influx, then de-water.

Perhaps sailors should pay attention to that experience?

The average sailboat carries perhaps a pair of 2000 gallon per hour pumps - which really with head, curved leads and such can pump 1500 GPH if said water is where the pump intake is (and from reading Practical Sailor reviews that 1500 is optimistic as all get out).
Installed, operating bilge pumps can buy time but unless you stop the influx that's it.

Consider a rudder stock fail and fall out - 111 gallons 850 plus pounds added in 60 seconds to the stern of the boat - think that water is conveniently flowing to the center and pumped out? Not likely, and every second adds more angle down at the stern.

Ditto the log strike at the bow, and add the extra water influx because you were moving forward. Can you get to your hull at the bow (under v berth, anchor locker etc) and plug a odd shaped ripped up hole while water is rushing in and you are upside down, in the dark?
It's about risk management, it's also about percentages :)

Planning, pre-positioning, preparing and practice and all the other P words and a few others.
 
#8 ·
Your time (what little you have) is better spent stopping of reducing the flow - not disconnecting engine hoses and leading them to the bilge.
The Navy teaches it that way - stop influx, then de-water.
Agree with that.

Also I don't like the idea of tampering with the thing that's providing the electricity to the real pumps and the emergency communications.

However, if a long way from shore and all influx reduction ideas have reduced it as much as possible and you would otherwise be sitting on your butt, then doing the raw water intake may be an idea....
 
#9 ·
If you ever find yourself in this situation, close the seacock (s) and take the intake hose (s) off the thru hull and drop it (them) in the bilge!
This old chestnut comes up all too often. It is itself a safety hazard.

Raw water pumps for diesel engines are generally sized at 15 gpm / 100 hp. If you have a 40ish foot boat with the ubiquitous Yanmar 4JH4E or similar the raw water pump will move about 8 gpm. I was surprised it was that high so I stuck a bucket at the exhaust outlet on my boat and it's pretty close. 8 gpm is less than 500 gph. Now run down to West Marine and price 2000 gph bilge pumps. Buy a couple. Spec the nice big Whale manual pumps and buy one of those also. Don't fuss with the engine cooling system.

If you really want to move some water get a trash pump from some place like Northern or Harbor Freight. You can run a trash pump as a direct drive off the engine (or shaft) or with an electric motor powered by a generator. Honda sells an outstanding gasoline powered pump that is the size of a canister vacuum cleaner.

Having participated in the development of US Navy damage control books I strongly agree that the priority is to stop the influx of water.
 
#16 ·
This old chestnut comes up all too often. It is itself a safety hazard.
I agree, this makes no sense for a sailboat. I'm wondering if it might make sense for a powerboat. Those 400+ CID engines require a lot more cooling. Still, you threaten your engine if you do it and can strand yourself -- without sails to save you!

Having participated in the development of US Navy damage control books I strongly agree that the priority is to stop the influx of water.
Hear, hear! That's why I talked about damage control. Get the water intake down to the minimum you can. We'd all like to see zero influx but in practice you never get there. My chiefs used to tell me that that in the general case 50 - 75% was achievable if the team was well trained.

Tom
 
#11 · (Edited)
Must have missed it, Minne..

I can say from experience that the most frustrating of all leaks are those from loose fastenings behind the ribs, because there is absolutely very little you can do, from inside the boat, to stop the flow of water... but.. wait... plastic boats probably don't have that problem. :)

A friend of mine, whose S&S 30 has a reputation for sinking on him whenever his back is turned, now has four 2000gph bilge pumps fitted!! He adds another each time the boat sinks. I guess that makes him feel like he's somehow addressing the problem.. He struck some nasty weather during the race from Melbourne to Geelong back in January and one of the bilge pumps seized up and shorted out. He was lucky - the boat would have caught fire if it weren't for all the water sloshing around down there. ;)
 
#12 ·
He was lucky - the boat would have caught fire if it weren't for all the water sloshing around down there. ;)
That's some strange "Luck"

I hope I didn't scare anyone with my previous post on influx rates and bilge pump inadequacies.

The deal is folks need to seriously consider the double pump configuration - a light pump to handle 'normal' leaks low in the bilge, and a heavier pump up higher in the bilge that kicks in when there is a real problem.

That second higher pump should have an alarm on it that will wake the dead.
 
#13 ·
On the prevention and finding of leaks. I made a line drawing of the hull and showed the positions of all through hulls. This is a laminated card and is kept handy. At sea we close all but a few. Tapered plugs on line by each through hull. I have a hand pump mounted on a board with hose in installed as a third manual pump. Just a few ideas.
 
#15 ·
No matter how well you are prepared, the ocean can always supply more water than you have pumps and fuel to handle. Always.

So you do the best you can, and when the weather shows a storm a thousand miles wide, you just don't go out anywhere near it. Especially in a replica of an obsolete boat that wasn't known for weathering storms very well.
 
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