Flooding Emergency -- Checklist

[capt-couillon]

interesting thread... One additional piece of equipment all may wish to consider is the standard 3 pound short handled hammer...

Not a joke, in event of collision damage, the area may be less than accessible for temp repair due to casework, bulkheads, etc. A 3# hammer will make short work of galley cabinets, bunks and or bulkheads that prevent the install and bracing of temporary patches.

Just sayin...

[thinwater]

While crash tanks and other bulkheads may not be able to make a ballasted boat unsinkable, they can sure slow things down. It often seem to me that folks dislike them because they block small amounts of water from draining to a central point, but... your funeral. They also create step-overs at doors. get over it, if it is important to you.

I don't see why partial bulkheads with or without valved limber holes don't make good sense. In most cases, the bulkhead need no rise much above the water line to be a huge help (once it fills, the pressure differential is reduced, and what ever comes over the lip is MUCH less. Probably the only viable option for a big hole.

[Oliver L.]

I don't think I have seen it anywhere - if I saw water in one of the hulls I would start dumping fresh water from the tank on that side. Helps with buoyancy and doesn't cost anything...

Oliver

[Dockhead]

Originally Posted by thinwater

While crash tanks and other bulkheads may not be able to make a ballasted boat unsinkable, they can sure slow things down. It often seem to me that folks dislike them because they block small amounts of water from draining to a central point, but... your funeral. They also create step-overs at doors. get over it, if it is important to you.

I don't see why partial bulkheads with or without valved limber holes don't make good sense. In most cases, the bulkhead need no rise much above the water line to be a huge help (once it fills, the pressure differential is reduced, and what ever comes over the lip is MUCH less. Probably the only viable option for a big hole.

Now we're talking about design, which is a bit of a different issue, albeit an interesting one.

As I've mentioned in a few places on here, I like Dashew's approach, which is to separate the boat into three completely separate compartments, and get all through hulls out of the middle, main space. That makes the boat almost unsinkable.

Failing that, we could at least have aft compartments -- the lazarette on my boat -- which have only a limber hole (and why not a valve on it) connecting to the main bilge. Cables and pipes run high up in the bulkhead above the waterline. Why this was not done on my boat I have no idea. There is a stout bulkhead between the laz and the aft cabin, but it is entirely open for about 20cm to the bottom of the hull .

I understand the desire to not have a separate sump and bilge pump, but a limber hole would fix that. And then you wouldn't be at risk of sinking in case the rudder (or skeg) gets ripped off in some violent grounding or other accident, or if there's a collision and hull breach aft.

I hate this so much that I think about glassing it over. The only thing which stops me is the large quantity of pipes (central heating, transom shower, engine room blowers, galley exhaust) and wires which run through there, which would need to be relocated.

[Jeff.Sailor]

Prevention beats cure.

For all the diligence we put into emergency response, I wonder if we do the same for emergency prevention. That's a good place to start.

Evaluate all areas of seamanship, crew management, boat maintenance, etc. to try to preempt the crisis from ever occurring in the first place. That's a great foundation to build from.

[KISS]

This calculator outputs the volume of the leak, if you input the diameter and depth below waterline of the hole. Been using it to think about cockpit drains, but would be useful for cabin flooding as well.

Anyway, the best prevention measure is to minimize the number of thru-hulls.

Far more boats sink from failed/open seacocks than from hull breaches.

[jackdale]

Originally Posted by Chris66

I would add to the list, at number 1, Taste the water. If it's not salty the problem may not be as dramatic as first thought. Probably not relevant if the water is up to your ears, depending of course on your water carrying capacity.

Look at and smell the water before tasting. I have split a holding tank.

[jackdale]

These are worth a look - as is the whole series

https://www.youtube.com/watch?v=bRhcXBtmPQs

https://www.youtube.com/watch?v=eUg3TUmnQBs

https://www.youtube.com/watch?v=H5PDuXvqL7c

[KISS]

As another poster mentioned earlier, the main factor is finding the leak early.

Basically, even a small breach/failed-fixture will sink the boat if not plugged.

None of the electric bilge pumps aboard recreational boats have a chance of keeping up.

...even assuming you have enough power, and the electrical system doesn't short out.

Step #1. Find and plug hole.

Step #2. Have trash pump to give time, or, one hopes, empty after hole plugged.

Otherwise, better hope you have a good lifeboat/raft.

[Ungvar]

There is something I am a little unclear on, in the first post and that is shutting down the engine. I understand you need to eliminate the possibility of a leak in the cooling water">engine cooling water system and you want to keep your air intake above water.

I know designs very, but I have 4 fixed dewatering pumps. 2 manual and 2 12 volt. The two 12 volt pumps, running full bore, provide significant dewatering capability, they would buy me time to eliminate sources of ingress, but they wouldn't take long to run down my batteries which are charged off my alternator.

If you left your engine on, slow revs ahead, you could point head too sea, reduce the effects of free surface in the bilge and create a much more pleasant working environment, reducing the risk of debilitating seasickness, which comes on fast in bilge water, even for veteran sailors.

Or, you could set your autopilot towards a nearby refuge or shallow beach, to Beach on, if there is one. Even if you're days away, maybe by dewatering and damage control you can at least put yourself closer to potential rescuers or shipping lanes.

Diesel engines in motion tend to stay in motion, but if you shut it down, how easy will it be to restart?

Sent from my XP7700 using Cruisers Sailing Forum mobile app

[Dockhead]

Originally Posted by Ungvar

There is something I am a little unclear on, in the first post and that is shutting down the engine. I understand you need to eliminate the possibility of a leak in the engine cooling water system and you want to keep your air intake above water.

I know designs very, but I have 4 fixed dewatering pumps. 2 manual and 2 12 volt. The two 12 volt pumps, running full bore, provide significant dewatering capability, they would buy me time to eliminate sources of ingress, but they wouldn't take long to run down my batteries which are charged off my alternator.

If you left your engine on, slow revs ahead, you could point head too sea, reduce the effects of free surface in the bilge and create a much more pleasant working environment, reducing the risk of debilitating seasickness, which comes on fast in bilge water, even for veteran sailors.

Or, you could set your autopilot towards a nearby refuge or shallow beach, to Beach on, if there is one. Even if you're days away, maybe by dewatering and damage control you can at least put yourself closer to potential rescuers or shipping lanes.

Diesel engines in motion tend to stay in motion, but if you shut it down, how easy will it be to restart?

Sent from my XP7700 using Cruisers Sailing Forum mobile app

Yes, I think someone else also made a comment to similar effect.

I think there are some good arguments here, and I think I would modify the checklist, adding a new step --

check and eliminate cooling water as the leak source

and shut down engine only if that's the source.

[Ungvar]

I know complicating checklists don't always make things safer, but just a suggestion.

But, you could look for obvious signs of a cooling water leak before shutting down. Creeping engine temperature or poor flow if you have a wet exhaust might be signs of a serious raw water leak.

Sent from my XP7700 using Cruisers Sailing Forum mobile app

[Dockhead]

Originally Posted by KISS

As another poster mentioned earlier, the main factor is finding the leak early.

Basically, even a small breach/failed-fixture will sink the boat if not plugged.

None of the electric bilge pumps aboard recreational boats have a chance of keeping up.

...even assuming you have enough power, and the electrical system doesn't short out.

Step #1. Find and plug hole.

Step #2. Have trash pump to give time, or, one hopes, empty after hole plugged.

Otherwise, better hope you have a good lifeboat/raft.

Yes, I think that's generally right.

It took me a while to realize how much pumping capacity you need to keep up with even a small leak.

I have:

2x 1100 GPH maintenace pumps
2x 4000 GPH main pumps

The ratings of recreational pumps are nonsense so figure half of this, realistically, and only until they clog and/or batteries are flooded and shorted out. So roughly 20,000 liters per hour.

I added to that a super massive 42,000 liter per hour trash pump, which will be run off the top of my high mounted generator. This pump weighs like 40kg and has a 2200 watt motor, and discharges through a 3" fire hose. I think its rating is realistic. The generator is located well above the waterline and will not get flooded before the decks are awash (at which point we will be in the life rafts).

So that's about 60,000 liters per hour total with all the pumps going. That's about 1000 liters per minute.

I believe that will control any leak from any single failed through hull, which will give as much time as needed to find and fix it, maybe even two. None of my through hulls is very deep underwater.

Of course if you have a bigger breach than that, all bets are off.


Which is why we have two Avon Ocean life rafts, both of which are going in for service tomorrow.


Someone said prevention is better than cure -- absolutely agree. I inspect and grease all my sea cocks and mushroom fittings every year; just did it. I replace them as soon as they show any signs of deterioration; I guess I've replaced four or five over the years by now. I exercise them all regularly, at least every couple of weeks. A habit of always shutting off sea cocks when off the boat overnight helps with that, plus puts the location of all of them in muscle memory.

Unfortunately you can't always see deterioration of the hoses and hose tails.

That's why I will probably just replace all of them ($$$) prophylactically the next time I have an extended haul out. Hate to do it, as they are all good naval bronze fittings, and will be expensive to replace, but 15 years is about as old as I would really trust, even with frequent inspections like I do.

Unfortunately keeping a cruising boat in safe condition requires constant investment.

[TurninTurtle]

And the oft forgotten when launching.... drain plug.

Note that on small boats the OEM bilge pump may or may not be on a float and may not keep up with that hole.

How would I know that?
And I couldn't reach it from inside or outside. (Not taking off the life jacket to dive between transom and outboard when solo and the boat is sinking, thanks.)

I calculated my drain plug could let in 1200 gph.

My bass boat got an upgrade from OEM 500 gph to 750 and then I added a 1500 gph on a float switch that turns on 2 inches higher than the 750.

Your float actuated pump(s) should be sized to keep up with the most likely leak that doesn't involve breaking the hull on a rock.

[jackdale]

Years ago I saw a suggestion to tee a hose (with a ball valve) off the raw water inlet hose to the bilge. In case of flooding open the valve and close the raw water intake. Keep the engine running. Instant bilge pump.

I have not seen any installation that was like this.