sinking fast

[andrewsc]

Heading from the PNW to Alaska this summer. It will be our second trip up. Watched a show on the Discovery channel with kids last night. Steel charter fishing boat in Alaska loses its prop shaft and sinks in alll of about 3 minutes. 8 people on board, a dinghy meant for four, no life raft, no epirb, vhf and electronics went down almost immediately. Fortunately there was an air pocket in the bow keeping it just above ater and somebody had a working cell phone. Coast guard got everybody off but it was about as close to going the other way as you can get.

I am not posting to hash over the obvious raft of inadequacies in their preparation. We have gear for managing damage control but after seeing this want to put it in a single organized bag. We have a ditch bag but what would people include in a damage control bag?

1. An asssortment of bungs
2. Collision mat
3. Rapid cure, waterproof epoxy putty
4. Bolt cutters
5. A tough rubber ball that will fit in stern tube and a board cut to fit that will wedge it in place (got this today after watching Disovery)
6. Silicone self sealing tape
7. Duct tape
8. Assorted hose clamps

Apologies if this is redundant and already been discussed. I am new here and couldn't find a previous thread but would appreciate ideas, especially on the best way to stanch flooding from a stern tube....

Chris A.

[osirissail]

Lets see, the other boat lost it propeller shaft and flooded through the shaft log. You item #1 should have one proper sized bung tied to the shaft log. But even better, attach a bronze or zinc collar inboard from the shaft log on the propeller shaft. If the shaft separates from the transmission flange it can only travel an inch or two and never leave the boat.
- - Besides having disaster repair materials as you list, it is equally or more important to have installed safety back-ups to prevent as many potential disasters as possible - before the can occur. Other words, think/plan ahead.
- - Rudders break off or drop off and if the rudder stock cannot exit the boat you will not have a flooding problem at least. Steering may suck but at least you don't have to bail while rigging a substitute rudder.
- - Operating the vessel cautiously in dangerous waters goes a long way to prevent collisions with debris/ice/rocks. Be proactive rather than reactive in your thinking. Just a suggestion. . .

[capnorv]

I always keep a spare zinc on the shaft inside so hopefully this can't happen...or I might be kidding myself.

[callmecrazy]

I think the sensible way to store bungs, from what I understand, is to keep them tied to the hole they would be intended to fill. IE: tie to the thru-hull fitting or the hose, or somewhere near the shaft. That way there is no trial and error with the sizing... But keeping the rubber mallet at hand is another issue.

Epoxy putty is good, but also something like g-flex that you can actually make an underwater fiberglass patch with, would be a reasonable addition. Of course, you need some spare glass to go with it...

what is a collision mat?

[andrewsc]

I like the idea of putting a collar on the shaft.

Here is a link to a version of a collision mat.

Survival Gear, CMAT01 - NEW!!! COLLISION MAT - Abandon Ship Equipment - Abandon Ship Individual Items - Vessel Storm Survival - Life Raft and Survival Equipment?

Ours is triangular and came with the boat when purchased. Not sure I would have purchased. Looks like it would be hard to deploy in any kind of seaway. We also have 2 watertight bulkheads forward and one aft.

Rudder shafts are above the water line.

[barnakiel]

The tube can be isolated and a separate pump installed, build a dam etc..

Best security is probably watertight bulkheads / compartments, so that if punctured, boat will not sink.

Another good security is pumps up to the max amps you can take out with the engine on - pumps controlling the inflow, you trying to patch the hole.

And making the underbody fully accessible.

b.

[Pelagic]

Apart from the good advice above….The very best damage control is regular inspections of every mechanical, electrical, plumbing connection on your boat.

At least once a year, usually while deep cleaning any area I inspect for corrosion, leaks etc… use some protective lubricants and try to tighten all connections.

It is amazing how often something will vibrate a bit loose or do the same because of repeated heat expansion and contraction.

Your best damage control is to keep tools handy (including small mirror) and get into the habit of checking and logging items that seem to have chronic problems or corrosion.

Much nicer to catch these problems at the dock

[rebel heart]

Keeping a bung next to any thru hull is a fine idea. You should have a "DC locker" (damage control) somewhere easily accessible that has your gear for such emergencies. Small crowbar, mallet, small saw, flashlight, two part epoxie-putties that can bond underwater, etc.

We have an Edson 30 that can truly pump 30 gallons a minute with relative ease. My wife was pregnant when we last tested it out and it was able to completely empty our sizable bilge in under two minutes.

Rebel Heart - Sailing, cruising, liveaboard blog and website - Eric's Blog - the manual bilge*pump

In classic Navy fashion, and what's supposed to happen on all commercial vessels, are drills. Unless you and whoever the rest of your crew are really know how what their roles are how to perform them properly you will probably not succeed to well.

Who finds the hole? Who mans the pumps? Who rigs the pumps? Who secures the helm? Who issues maydays or otherwise sends alerts out? Will one person pump while the other person tries to stop the leak? Who's who? Would you consider going over the side to stop a leak from the outside of the hull?

DC gear tends to end up at the bottom of a locker and never tested or serviced because it's used so rarely (if ever).

Take a garden hose and fill up the bilge. Assign some roles as to who will do what, and practice going through all the steps. Seconds and minutes count big time if you're taking on water. Try to do those drills as often as you can. It might seem a little ridiculous but safety is no joke and if you're unlucky enough to flood you'll be the smart one who did all your prep work.

[Pelagic]

I had a commercial tug sink under me in about 3-4 minutes during a winter gale in Georgia Straight, BC.

When the alarm went off, I looked in the engine room, saw a waterfall, closed the door and immediately sent a Mayday via VTC.

We launched the liferaft and I stepped off from the bridge roof when the water got inside the dickens diesel stove behind the bridge. VTC radio Log said 4 minutes when I confirmed we were taking to the liferaft

Tug sank in deep water and when the insurance sent down a ROV to inspect, they found the main fastenings on 5 stern planks had sprung free and there was a large opening in the stern.

Turns out a previous operator while working the tug the week before on the West coast had got the tug pinched and squeezed between 2 large offshore chip barges, he was shifting at the pulp factory.

My delivery trip back to Vancouver worked everything loose and the gale opened it up.

Lesson confirmed when you see that amount of water coming in, get the liferaft in the water first then think about saving the boat.


Sometimes fate has already dealt you the cards

[rebel heart]

Pelagic: yikes. Never had a boat sink from underneath me yet. I'd like to keep it that way if at all possible.

[andrewsc]

We do have watertight bulkheads. 2 forward and one aft which includes the engine sapce a rudders. There are 2 of the ganged Rule 8000 gph bilge pumps in the engine space with a good array of electric pumps in other compartments. We also have 2 whale Gusher 30 manual pumps, one stored forward and one aft.

I appreciate the ideas and think that we have the basic equipment. It is scattered but I will plan to create a dedicated DC locker with everything except the bungs.

Agree that prevention is far and away the best strategy but realized we could be more organized. An experience like Pelagic`s lets you know how fast this can happen. Thanks for the ideas.

[S/V Alchemy]

Originally Posted by capnorv

I always keep a spare zinc on the shaft inside so hopefully this can't happen...or I might be kidding myself.

No, my wife was on a delivery and the shaft actually snapped just aft of the coupler and the zinc forward of the cutlass bearing kept it in the boat and the water out.

What they called a "teachable moment" or whatever!

[Feral Cement]

Originally Posted by andrewsc

Watched a show on the Discovery channel with kids last night. Steel charter fishing boat in Alaska loses its prop shaft and sinks in alll of about 3 minutes.

Something doesn't add up. Shaft size is to some degree proportional to other specs (LOA, Displ., etc.). If you pulled my shaft out, I'd have a lot more than 3 minutes before there was a call to abandon ship. My 27 footer holds at least 3000 gallons, and at a gallon per second, I'd have 50 minutes without pumping anything.

John

[andrewsc]

Its TV. I'm sure there's some degree of poetic license/need for drama. Maybe the whole stern tube pulled out of a rusted out hull. Doesn't matter. Still a good opportunity to tighten up my DC plan.

[andrewsc]

Assume a 4 inch diameter shaft log. The stern is just below the surface(btw 1 and 9 ft, 2 to 4 atmospheres ). The flow rate would then be 28 to 42 thousand gallons per hour.... Thats a lot of cold water. We are purely in the world of theory here but it seems like there is a worst case scenario that should be addressed.