Stuck in the mud

[Project_Mayhem]

The yard is having a lot of issues under it's new management. I ran into the new director and he mentioned that they had a boat that's stuck in the mud due to low lake levels. How would one go about resolving such an issue? Obviously if it was by a crane, they probably would've just used that (assuming it wouldn't put too much stress on the keel/hull joint).

This is post is intended to debate an interesting problem, not actually solve it

 

[jssailem]

It is the boat and not the owner. Two different problems. One booze might help. Break down barriers.

The boat would be more challenging.
Asking the question just a little or up to the gunnels.

• Applying physics one might lighten the boat to float it higher.
• I’d imagine one could try to heel the boat to get the keel free and float it on its side.
• They raise boats off the bottom of Lake Michigan by attaching air filled bags. This might get the hull a foot out of the water freeing the keel from the mud.
• If the keel is detachable, one might undo the bolts and see if hull can float free.

Or leave it as a decorative message to all boaters: “Do not do what this guy did“

 

[dlochner]

The water levels on the Great Lakes are closely monitored. The USACE publishes the data as do other agencies including the St Lawrence Seaway Commission. They are also pretty good at predicting levels out a month or two. Since the marina seems to be in a marginal area in terms of water depth it would be wise to closely monitor the data. There is also a lot of historical water level data online.

The boat owner should also monitor the data especially if they have a deep draft boat. Boats with deep drafts should be moved to deeper water in the marina or the owner move the boat to different marina.

To get this boat out, first lighten it. remove as much weight as possible; remove sails, gear, empty water tanks. Try heeling the boat in the slip and sliding it out. Since local water levels in the Great Lakes can be affected by wind, try moving the boat when wind is blowing water into the marina.

Detroit District Water Management

water.usace.army.mil

 

[duality]

which yard?

 

[Scott T-Bird]

We had a noreaster storm last Thursday that pushed water into the bay and our marina and raised the water level to within about 6-inches below dock level. Soon after, a strong west wind pushed the water out and our keels where resting on the bottom. Topsides were exposed about 6" below normal waterline on Saturday morning - just about everybody in the marina was stuck. The total swing was about 54 inches! Our normal tidal variation is around 6 inches. Luckily, it won't be long before sea level comes back to normal!

 

[ShawnL]

I've actually seen it on Keweenaw Bay in the UP, on Lake Superior (we called it a seiche). There's a stretch of road with the lake / bay on one side and a deceptively deep marshy area on the other. On one trip you could see the 'tide' coming in with quite a bit of speed and the beach being swallowed up. About an hour later, on a return trip the opposite was happening. The marsh was emptying back out. No real wind to speak of, at least not enough that we noted it. Very cool to witness.

 

[capta]

Do not try to pull from the top of the mast. Please. In my experience, it dismasts the boat more often than not.
The suction of the mud will add to the difficulty in refloating her again.

 

[Project_Mayhem]

Would pulling the hull with a crane put a lot of strain on the keel to hull joint or sub frame if the keel is suctioned to the muddy lake bed?

 

[dlochner]

Would pulling the hull with a crane put a lot of strain on the keel to hull joint or sub frame if the keel is suctioned to the muddy lake bed?

Possibly, the pull would need to be slow and steady. Once the suction is broken it would come up. It would also depend on the nature of the mud. Some mud is thick and sticky other mud, especially if it is full of organic matter, is pretty soft and almost liquid. The suction can be broken by injecting water along side of the keel. Attach a garden hose to a section of pipe and stick the pipe next to the keel and turn the water on. The water pressure will erode some of the mud and reduce the suction. Pilings are set and removed using this technique.

 

[jssailem]

What type of keel?
Fin, winged, etc?
How deep in the mud?
Will the crane be pulling up vertically or from a horizontal angle?
What type of lake bottom? Silt, clay, or sand?
Is the keel bolted on or molded into the hull.

 

[rgranger]

Could you run a firehose down to the union of mud and hull and hydrolically lift the boat? The boat is meant to float so once you get a layer of water between the hull and mud, it should separate.

 

[shemandr]

In my experience fin keel boats tend to lean over when they are left in too shallow water by tide or seiche. So I've never witnessed one that got stuck in the mud. In a slowly lowering lake situation it may be different. Normally the wave action causes the boat to wiggle enough to burrow a depression around the keel and suction does not develop. This was common in a marina in New Suffolk, NY. You could see the holes when the Winter winds would blow the water out.
Wing keels might be different. But I had one, which was occasionally on the bottom, and it didn't get stuck.

 

[jssailem]

It is not clear at what state has developed. Is the boat lashed to. A dock and still floating? Is the boat stuck high and dry?

 

[jssailem]

Up here in the PacificNW the tidal change is dramatic. 10 to 12 feet is not abnormal. On those extreme low tide days some of the boats on our dock are “STUCK in the MUD” as there keels are buried in the silt from years of river/tidal flushing. We play the game Stuck - Not Stuck as we walk down the dock pushing the bow of the boats to see if they move. I am glad to own a boat with a 4.5 ft 2/3’s long keel draft not a plus 6ft fin keel and am closer to the fairway of the marina where the mud bottom accumulation is less.

 

[High Current]

Growing up in ME where we also have 10 ft tides, my first reaction was "just wait for the tide to come in." Lake levels might be on a much a longer time scale, but it certainly seems the most cost-effective solution...

I like the air bags idea. Or something similar - build a lifting raft out of dock barrels?

Barge with a crane?

I wonder...how much would it cost to hire a heavy lift helicopter?

 

[Timm R Oday25]

If it were my boat , I'd use empty 55 gallon plastic barrels on both sides . The 3" wide ratchet straps would go from a barrel on one side ,under the boat and around the barrel on the opposite side . Depending on the boats length , perhaps 4 barrels per side for a 30 footer . Once the barrels were in place ,I would slowly ratchet the straps closer in sequence . The barrels are cheap ,readily avaiable and wont scratch the hull .

 

[WayneH]

Down here on the Gulf Coast, 10-12 INCHES is abnormal. And usually due to the last cold front blowing all the water out of the bay.

 

[shemandr]

. I wonder...how much would it cost to hire a heavy lift helicopter?

I think the bill would exceed the value of the boat by ten times or more.

 

[dlochner]

Lake levels might be on a much a longer time scale, but it certainly seems the most cost-effective solution...

Lake levels are seasonal. High water won't return until June. How high the water goes also depends on precipitation. A dry summer and snowless winter makes for lower levels. Several of those years in a row and the lakes get very low. Michigan, Huron, and Erie are not controlled by dams. Ontario is controlled to an extent by the dams on the St Lawrence Seaway.

 

[dLj]

It's unclear to me where the boat is located. Guessing that it sounds like it's in its slip. That makes things a bit more complicated. I'd first do a bottom survey to know how deeply the keel goes into the mud, what mud consistency, and where will the boat be moving to in order to know if there is enough water to move it without it getting stuck again elsewhere.

Without that survey, it's hard to know what method to use. You need to know how much flotation you need and where you are going to move it to. If you use a crain to pick it out of the mud, where are you going to put, first the crain, and second the boat?

If the boat is in the slip, you likely can't lean the boat over and move the boat at the same time - too many things in the way.

Lightening the boat is good, but you need to know how much you need to move the boat upwards to get unstuck. Adding flotation is probably the easiest given the constraints of being in the slip. However, mentioned above using ratchet straps is not how that is typically done. You sink the plastic barrels full of water, attach to the hull with the bottoms facing upwards, then you use compressed air hoses and fill the barrels with air pushing the water out that way. That way you can make a solid connection to the boat with the barrels in their position and you can control the flotation better by controlling your compressed air flow. They make flotation bladders but they are pricey. Cheap plastic barrels are easier.

But no matter what is done, you need to know both how much flotation is required and where you are going to move the boat. It's a real drag floating the boat in the slip only to get it stuck somewhere along the route...

dj