Shaft Seal Failure

The picture is of a 85' Hatteras that sank on July 12th. The captain said, "one of the shaft seals had exploded and water was gushing in as though from a fire hose." The were 3 adults and 3 kids who all got off safely.

Here's the story:

Latitude 38 - 'Lectronic Latitude

Greetings,
Never have and never will trust the buggers. A "traditional" stuffing box gives one plenty of warning of a failure. Better idea...indeed.

We repacked our traditional stuffing box while in the water and while the ocean was trying really hard to get in the boat, it was far from gushing in like from a fire hose. Maybe the whole works (prop & shaft) fell out?

RT Firefly said:

Greetings,
Never have and never will trust the buggers. A "traditional" stuffing box gives one plenty of warning of a failure. Better idea...indeed.

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ditto ... and traditional packing is so advanced now it is all but dripless if you watch it every couple of days worth of operation.

I have actually replaced our PSS with the boat in the water. With it totally disassembled the water entering the boat was not even enough to make the first bilge pump run continuously, just a little intermittent. Something else had to happen.

Another example of "KISS" ignored.

rochepoint said:

I have actually replaced our PSS with the boat in the water. With it totally disassembled the water entering the boat was not even enough to make the first bilge pump run continuously, just a little intermittent. Something else had to happen.

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I would agree with this!!! I just had my shafts replaced and the yard manager took it upon himself(which was fine with me) to replace the shaft seals since the shafts were out and the parts were not expensive. What I thought was kinda cool is he put an extra seal on the shaft in between the stuffing box and the coupling that could be used if needed...just slide it on!

I have to say that sounds strange. I know my pumps can stay way ahead of any water coming in around the shaft. It doesn't sound like they tried to stop the water either. It took about an hour for the rescue boat to arrive and they still had time to drop the kids off and go back for personal items. Even if the shaft broke, it's unlikely that it would have fallen out. Most likely it would have just slipped aft until it hit the rudder. Doesn't sound like an insurance scam. You don't sink your boat with your own kids aboard. Very strange.

HopCar said:

I have to say that sounds strange. I know my pumps can stay way ahead of any water coming in around the shaft. It doesn't sound like they tried to stop the water either. It took about an hour for the rescue boat to arrive and they still had time to drop the kids off and go back for personal items....

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Bilge pump failure + delayed investigation for boat listing + panic = this scenario?

Murray I bet you're right when you mention panic. Look how high it's floating in the picture. It looks like they've already launched the rib and abandoned ship. Of course with kids aboard, getting them off into a nice big rib right away might have been smart. It also looks like they had a Boston Whaler type boat but it's out of it's supports and sitting cockeyed. Maybe they tried to launch that too but couldn't because it was on the high side of the list. I'd love to hear the Captains story of the sinking. I bet there are lessons to be learned from this.

Sounds like there was probably more to the story. Maybe there was damage to the shaft log itself to get that kind of water flow. Just losing the packing gland or the dry seals shouldn't cause that kind of flooding.

One of our gillnet boats had the hose clamps fail and the gland seperated from the shaft log on the way in. The boat skipper didn't even notice until he got back to the dock and saw the pumps were running.

Edelweiss said:

Sounds like there was probably more to the story.

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I agree. I also believe that the rest of that story doesn't have anything to do with shaft seals.

Ditto, conventional shaft seals for me either. Modern packing material OK but no bellows seals for me.

How could that much water come by the hull fitting even with no seal in place? No high water bilge alarm? No indicator light/buzzer on the automatic bilge pump? I don't get it.

This does bring up a question though.

How many of us have functional emergency dewatering pumps aboard our boats?

How many of us have a high bilge water alarm that will sound a buzzer or light enough to wake us if we are asleep?

I'll be the first to admit that although these things have kept me up at night thinking about them, I at this time do not have adequate systems in place.

My boat is equipped with what is probably standard factory bilge pumps for its vessle size. There are three sets of pmps, 750 GPH with each set being a automatic pump, backed up by a switch operated pump.

Two sets are in the engine room one forward, one aft, and we have a watertight bulkhead seaprating the engine room from the forward areas. This bulkhead has a sealing door which we keep closed and dogged down.

The third set of pumps is in the forward areas.

If any of the pumps operate a light comes on at the helm indicating which pump is running.

We also have two high bilge water sensors that I installed above the level of the automatic bilge pump switches, one forward, one in the engine room. If either of these operate it triggers my alarm system and I get a text and e-mail indicating the condition.

My plan is simple. My alarm system has a relay output that I can program to operate on any of the alarm points. I'm going to install a light and or horn, loud enough to get noticed so that if we get high bilge water we'll know about it right away.

I also wanted to install a very high capacity dewatering pump in the engine room. This would either activate automatically along with the alarm horn, and or have a manual switch for activation. It will for sure have a manual switch, the automatic part is optional.

While catastrophic flooding does not happen often, it does happen. Case in point was last year a 5788 Bayliner sunk due to catastrophic engine room flooding in between Kodiak island and the mainland. all hands were rescued but the boat was lost.

Thinking about the sinking of the Hatteras that was the basis of this thread, would things have turned out differently if they had a dewatering pump?

Something like this would do it.

Barnes model QDX33-SS all stainless construction, 1.5" discharge, 5700GPH at 5' of head, 6.8 amps AC powered. $406 at Grainger.com

I do have a seperate float switch at the top of my bilge sump which has an automobile horn which will wake me when asleep and which I may hear from ashore. I also have a Y valve on my engine raw water intake so that I can bring the raw water pump into play if needed provided the engine air intake is not underwater already.

"The best bilge pump is a scared man with a bucket"

How about phot of horn arrangement ? Also have manual switch ? Think could hear horn over engine noise from fly bridge ?

I have one of these horns connected to one of my bilge pumps...the one that always comes on last....second pic.

90dB Piezo Pulse : Piezo Buzzers | RadioShack.com

It's almost painful to stand next to...certainly would wake the dead anywhere on my boat and is easily heard down the dock several slips even when all shut up.

The first picture is something I am considering carrying on board...especially as I travel a tad further offshore every year. Much better than being scared with a bucket...being in the salvage business....they are impressive compared to even the largest electric bilge/sump pumps.

3" Full Trash Pump with 212cc Gas Engine

psneeld said:

The first picture is something I am considering carrying on board...especially as I travel a tad further offshore every year. Much better than being scared with a bucket...being in the salvage business....they are impressive compared to even the largest electric bilge/sump pumps.

3" Full Trash Pump with 212cc Gas Engine

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I have considered the gas trash pump option, and while it certainly has much more capacity than an electric pump, and it'll work when the electrical system is underwater, its just not for us.

The reasons are simple...

That kind of unit takes storage space, space is a premium on any boat, mine included.

It also takes gasoline, which further reduces the available places I could store the unit.

It also takes time to deploy, and effort. I have a difficult time imagining in the middle of the night, taking the time to deploy that unit, with all the other things such as trying to find the source of the flooding, Calling a Mayday, preparing and or considering wether it will be necessary to abandon ship, that would be happening if a high bilge water alarm went off.

My thoughts are if you can throw a switch to activate a reasonable dewatering pump then its something you would actually do in an emergency, even prior to trying to isolate the source of the flooding.
At 95 GPM that should at the very least buy you and your family time.

The trash pump concept is a great idea, its just not for us. We'd probably never deploy it.

sea hag said:

How about phot of horn arrangement ? Also have manual switch ? Think could hear horn over engine noise from fly bridge ?

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Sorry, no photo. Just a Rule switch and a horn from Autozone. No manual switch, no switch at all actually, just a fuse and wired to battery bus bar. Yes, I can hear it from the bridge (and shore) because the horn is on the bridge.

I have the same set up as Brooksie, and horn is in fly bridge. good set up.

mike

I have been thinking of adding some form of dewatering pump, but haven't yet. Lots of possibilities out there, maybe if you have a generator, an AC powered high volume pump??? There is probably no one good answer for all applications, but would like to hear some options?

On our gillnet boats, we had belt driven 1" or better Jabsco dewater pumps on the main engine. The pumps were either engaged manually by pulling a lever which tightens the belt on the pump pulley or with an electric clutch pulley. Both are pretty simple, but it does require some engineering.

Diverting the engine raw water pump to dewater a boat will work, but has its risks and should be a last resort. Have seen a couple of complete loss of power and engine ruined. Because either the pumping volume exceeded the flood water flow and ran the pump dry ruining the impeller and another sucked debris up and plugged the pump/cooling system (plastic bag - the owner stored spare filters in zip lock bags.) The boat had to be beached when the engine overheated. A crew member must be assigned to monitor the pump and ensure it has water. Hard to get someone to sit in the engine room and do this when you have a declared emergency.

Edelweiss said:

I have been thinking of adding some form of dewatering pump, but haven't yet. Lots of possibilities out there, maybe if you have a generator, an AC powered high volume pump??? There is probably no one good answer for all applications, but would like to hear some options?

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Because we have a large inverter, and a generator I thought the AC powered route would be best for our boat.

I was thinking about running the output to a through hull high above the water line. Possibly I could have a quick detach fitting like on a trash or fire pump and a length of hose onboard.

Then if I retained the plug in power cord, the pump could be easy to remove for testing, or helping out another boater.

I have a similar type pump at home and use it to water our lawn (we live on a lake), and have found them to be very reliable, providing many years of service day in and day out. I found the stainless model because I was worried that salt water would corrode a cast iron pump and reneder it inoperative when you need it the most.

Trash pumps are definitely the way to go...you can just buy the pump portion and hook it to a clutch/engine pulley, a giant electric motor, or a hydraulic motor if set up that way. The smaller 1.5 and 2 inch still outperform an army of electric bilge pumps. The Gas pump can be mounted in a box on deck and some of the plumbing permanently installed. The carb can be connected to a dingy gas can for quick start up. The whole rig may take just a minute or two to set up if the placement of pieces and parts are there already.

As a salvor..I gotta tell you there's nothing like them for dewatering...

The electric sumps and bilge pumps have very overly optimistic ratings....

But as I said...there are many options and configurations...one or several are worth exploring.

Gasoline powered trash pumps are extremely efficient at dewatering operations however I would caution against assuming that commercial duty 110 VAC pumps are at all similar to the bilge pumps sold at the marine stores or the Home Cheapo homeowner equivalent, very far from it. That said a gas engine works when the generator or inverter crap out so has my vote for out on the water work. If my boat where large enough and going offshore you couldn't talk me out of having one aboard, couple gallons of gas be damned.

I'm a simpleton and read the statistics from Boat US(my insurance company) and noticed that far more boats sink at the dock than away from it. I use ZOELLER Pump, Sump, 3/10 HP - Sump Pumps - 2P549|M57 - Grainger Industrial Supply plugged directly into the dockside power outlet, not the boat. Discharge water is directed out of a surplus 1 1/2" exhaust hose for the old generator that was removed by the PO. If my 12 volt system craps out at the dock during a flooding incident in my absence the likelihood that the marinas AC power will fail too is remote enough for me to feel is an acceptable risk.

Of course this will be of no help away from the dock but that's not the emergency I had in mind when designing it. High water alarm is a future project, some great ideas in this thread.

rochepoint said:

Something else had to happen.

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I'm not an insurance investigator but given these photos and the explanation I just read, I think I could come up with a pretty good theory as to what "really happened." (Scuttled?)

A couple of months ago I was on a sport fish boat that was hooked to a large fish and backing down. Eventually enough water came in and worked its way below that the freeing ports were under water. When I looked in the engine room, I saw two big 2 inch sea strainers feeding water to the engines. It sure would have been nice if we could have used those to pump the bilge. There was no shortage of crew on board and the freeing ports were stuffed with towels and then the bilge pumps and bucket men started to make very slow progress. The Coasties showed up and put a 3" gas powered trash pump aboard and that made short work of removing the water. I'm in favor of anything you can do to increase your pumping capacity.

" I think I could come up with a pretty good theory as to what "really happened." (Scuttled?) "
That was my thought as well, but they had kids on board. That would be a pretty cold thing to do with kids on the boat.

HopCar said:

That was my thought as well, but they had kids on board.

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Makes the story all the more believable!

There is also the other possibility. . . . total lack of mechanical skills!! Shocking how someone who owns and personally runs a boat can have no mechanical skills, but I see it on a regular basis. These are often the same people who pay a maintenance company to prep their boats. When they're away from the dock and out of range of "on call mechanics", they're totally unprepared to deal with the simplest problem.

We were at Sucia Island earlier this year and a man approached us and was looking for a ride for him and his family to Roche Harbor, San Juan Island. His 50' boat was anchored in the bay with fuel system problems, (probably plugged filters) and a mechanic couldn't come to fix it for a couple of days. His family didn't want to wait around and his wife wouldn't ride in the skiff. He didn't have any idea how or the desire to trouble shoot and fix the problem.

His intention was to leave the boat anchored there and move on.

A 2 inch hole 3 feet below waterline will let in close to 3000 GPH.

A blown out shaft seal. maybe 1/2" = 750 gph. If you did nothing it could sink you.

SD