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Goodwin Sands

Habebty

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Already provided one quote and explained i don't currently have access to other sources I've come across (of which i haven't kept a record). Several references in old books i no longer have plus references in newspaper reports in the 19th century which i would have to pay to access.

In the case i quoted which i have researched, there was absolutely no suggestion that the barge was damaged and unseaworthy. Indeed, her mast and rigging was still standing

However, i am reminded of a known (and again documented) problem with working narrowboats drying out between tides in the channel below Brentford Lock off the Thames

It was not unknown when the tide returned for a boat to remain stuck in the mud and fail to float off and then inevitably fill with water as the tide topped the gunnels (the working boatmen used to sling a heavy rope under the hull before the boat dried out which could be dragged backwards and forwards to break the suction if necessary)*

So a hypothesis might be that with flat, or flattish, bottomed boats such as barges (and many coastal merchant ships - typically East Coast colliers were flat bottomed for example) a combination of scouring and liquefaction might initially cause the boat to sink into the sand to its marks

Then, as the tide rose, suction and/or the sand solidifying around the hull might prevent the vessel refloating leading to downflooding when the tide rose above the level of the deck or openings in the hull

Subsequent tides, now scouring around a waterlogged vessel, might then lead to further sinking into the sands

* Lest you doubt this... there are photographs and first hand accounts of it happening and i have personally experienced our motor initially failing to float off the mud in Brentford Basin when the basin was refilled after a paddle failure caused it to drain overnight. Whether she would have remained stuck and flooded is a moot point cos a combination of the flotation of our butty moored inside the motor and some serious grunt from a BW tug fetched her off into deeper water.
Hi Bru
The experiences of narrowboats failing to refloat on an incoming tide after being stuck in glutinous mud is indeed something I can happily believe, as I have heard several anecdotal accounts of boats ”taking a while” to break suction, particularly if the narrow boat was heavily or unevenly loaded Leaving little in the way of freeboard.
But then,flat bottom lighters/barges littered the drying Rivers Lea and Channelsea etc. waiting their next job without sinking. In fact, take Gravelines marina, Watchet, or any harbour like Portsmouth where I grew up, vessels regularly take the mud And rise on the tide.

Just for interest...a good example of a misleading story.
https://www.newsobserver.com/news/state/north-carolina/article242456871.html
 

PeterWright

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In the video of the guy poking a stick into a puddle of "liquified" sand, you have only to observe the force necessary to pull the stick out and the way it lifted a lrge amount of liquid and with itself to see for yourself the capacity for such a slurry to exert a lage downward force. If a ship's hull settles into a slurrified sand under its own weight as the tide ebbs, and that slurry then dries as it ebbs further, it's quite normal for the vessel not to float again until the flood has come well above her marks to overcome the hold the and has taken on the hull, even if the hull remains entirely watertight. Whether the additional buoyancy required to lift her out of the sand is sufficient to get her decks awash and (sandy) water getting below or not is a matter of fine balance depending principally on her freeboard. (minimum freeboard for a trading sailing barge was the width of her iron band - 3 inches). onve the sandy water starts to get below, all is lost - she will sink and with each subsequent tide will take on more sand until she's full. It's the weight of water that sinks her initially, but the weight of sand that drives her deeper into the slurry for the hull (but not the rig, if it still stands) to be "swallowed". None of this isdifficult to understand if you think hard about the relative densities ofwater, slurry and sand and the necessity foe air to get into the area where the hull meets the stand before the normal rules of buoyancy apply.

Thames barge masters who were reduced to visiting offshore sands in fair weather to fill their holds with ballast by shovel and barrow knew well of this phenomenon and took great care to ensure that they were beached in an area where she would float off easily before they started loading and often moved a bit between tides (it took several tides to shovel and barrow 80 tons of sand) to keep her free. When a laden ship grounded inadvertebtly on a sand, they had no option of floating off while light and very buoyant before the tide came back.

Peter.
 

Bru

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In answer to the several times asked, with variations, question "why doesn't this happen here or there or wherever" ... it didn't even happen regularly or consistently on the Goodwins or Thames Estuary sandbanks!

I think we have collectively developed a plausible and feasible explanation as to how a seaworthy vessel might, on occasions, become waterlogged and "swallowed" by the sands but only when a combination of factors all came into play together

Most grounded vessels, if they didn't break up, did indeed float off and were not lost. Even sunken vessels were salvaged (as I've previously mentioned, when the Defence was lost another barge grounded and sunk nearby in the same gale was salvaged successfully). Disappearing into the sands was a rare phenomenon but not so rare as to be forgotten between occurrences
 

Hallberg-Rassy

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What is being treated with some scepticism, is that a well found vessel simply sitting on the sand will be swallowed up. It may well settle due to local scour but will not "sink" because it will always be more bouyant than the sand, liquified or not.

Your point about the density of hardwood (or any wood for that matter) on a wreck, does not take into account the heavy stuff like a keel bolted to the the hull.
I did actually (keel). I'm actually thinking with a little incentive, of which I have none to be honest, one could even do the maths on all this and come up with pretty good predictions of when it is likely to do what. The proportions of the sand-clay-water* mix is one. I'm thinking any resonant rocking movement of the boat caused by tide or wind will be another.

However, what you're not taking into consideration is the multiple disappearance and reappearances. There are apparently random cyclic movements in the sands as well, which is what I was trying to hint at with the videos of "sand bubbles" of differing specific densities, and reference to helical movement.

In general, there are no "mysteries", just science that hasn't been worked out yet and what interested me in the few papers and sources I read, that it's all very current work. One was 2019.

* I guessing in various sands you'll have different mixes of river silt clay and ocean sand, the former running through the latter like rivers and sinking in time.

 
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Daverw

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all our boats at our club sink into the soft mud/ sand each tide nearly to the water line and each tide all float, this is over 100 boats each tide and all keel types, never seen one with any issue. All move about and rock away quite happily. There must be something else going on as I’m sure the reports cannot all be wrong
 
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Hallberg-Rassy

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I read the Goodwins are anything from 80 to 180 feet deep with no shoreline to hug. I'm guessing that makes a difference.

There's also the phenomenon of sinkholes in dunes and swamps. No idea if you get marine sinkholes but I'd say it was likely.
A ginormous 400-foot deep sinkhole in Louisiana is expanding and today swallowed a boat.

Two clean-up workers who were in the boat had to be rescued before they too disappeared into the watery mass, which today grew by another 50ft, authorities said....the massive sinkhole in the Louisiana bayou swallowed all of the 100-foot trees in the surrounding area and led to mandatory evacuations.
 
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Gary Fox

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A slight digression, not unrelated; this surely happened, and I've heard it in various similar versions, but I have no online sources, and maybe someone has more specfic knowledge:

A trawler, early 20th century, went missing and was found upon the seabed, completely intact, with no damage or defects.

There was no reason found why she should have been down there, after the most rigorous inspection; the weather had been fine, crew happy, no war or terrorism at the time, and so on. All the machinery, seacocks and plating were perfect, and no mayday went out. The investigators were bemused, and after the usual accusations of human error and insurance fraud, the hypotheses became more and more outlandish: alien death rays, mass suicide?

Someone thought to have a closer look at the seabed, and for the first time, and much to their surprise, geologists were consulted. They soon responded that the area was full of high-pressure reserves of subterranean gases, and they showed evidence of enormous seabed gas vents having previously burst.

The conclusion was death by misadventure, or Act of God.
The ship had been incredibly unlucky enough to steam near a huge pillar of billions of cubic metres of rising gas, emanating from a rupture in the seabed and bubbling up to the sea surface.
To the crew, the foaming surface disturbance would have resembled a gigantic shoal of fish, representing a fantastic trip, and they fatally altered course directly upon it.
However, the great column of bubbles was unable to support the trawler, her buoyancy vanished in a few seconds, and she plummeted to the seabed with all hands.
Imagine it.
 

Capt Popeye

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Bit of Fred Drift ere; when in North Kent some years ago, there was a local report of a Woman disapearing into Hole that had suddenly opened up as She and Child were walking through a Walkway between Houses, its reported that the Woman managed to throw the Child away from the hole, to safety, I suppose a She was sinking into it, the Child was found OK, but the Woman was never recovered from that Hole, despite searching for Her.
It happened upon a Chalk surface, reports at the time, if I recall rightly, stated the Hole was as a result of under ground streams of water running through and rainwater feeding them, causing cavens to be formed as the Chalk was being gradually washed away, eventually the ground above not being able to take the strain, so collapsing inwards.

Could a similar happening happen on those Sand Banks by sea water flowing though openings formed deep down in the Sand Banks many years ago ?
 

seivadnehpets

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Has anyone considered the proportion of below waterline surface area - to freeboard.
This could easily explain how a loaded barge is at far greater risk than a modern leisure boat.
I wouldn't like to try to free a big barge from sticky mud, but would expect sand to be less troublesome. But even in sand, with a small freeboard, the result could be catastrophic.
Another consideration is that the weather that puts the loaded barge, forcefully, on the sand, could also likely break the boat even if it isn't immediately evident.
I should be alright in my sailing dinghy ( ;}
 

Habebty

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Yes
Has anyone considered the proportion of below waterline surface area - to freeboard.
This could easily explain how a loaded barge is at far greater risk than a modern leisure boat.
I wouldn't like to try to free a big barge from sticky mud, but would expect sand to be less troublesome. But even in sand, with a small freeboard, the result could be catastrophic.
Another consideration is that the weather that puts the loaded barge, forcefully, on the sand, could also likely break the boat even if it isn't immediately evident.
I should be alright in my sailing dinghy ( ;}
yes, about 2 pages up. :)
 
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Habebty

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Bit of Fred Drift ere; when in North Kent some years ago, there was a local report of a Woman disapearing into Hole that had suddenly opened up as She and Child were walking through a Walkway between Houses, its reported that the Woman managed to throw the Child away from the hole, to safety, I suppose a She was sinking into it, the Child was found OK, but the Woman was never recovered from that Hole, despite searching for Her.
It happened upon a Chalk surface, reports at the time, if I recall rightly, stated the Hole was as a result of under ground streams of water running through and rainwater feeding them, causing cavens to be formed as the Chalk was being gradually washed away, eventually the ground above not being able to take the strain, so collapsing inwards.

Could a similar happening happen on those Sand Banks by sea water flowing though openings formed deep down in the Sand Banks many years ago ?
I would doubt that would be the case, as the bouyancy issue would still have to be overcome, which does not apply in the case of anyone disappearing down a land based sinkhole. The case of the American fisherman involved a breakthough into a large limestone cave network or a large dissolved salt dome, I cant remember which, and a whirlpool.
There are two possible sink hole locations I know of. There is " The Hole" at Stone Banks just off the Medusa Channel, and "The Mixon" just north of the Looe Channel. Both are only of a size that would consume a small vessel and there are no wreckage bits in the bottom that I have heard.. Both are very old and have a solid bottom. Until someone does a ground penetrating radar survey of the sandbanks, we will never know.
 

Gargleblaster

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I have started rereading 'Moby Dick' (1851) and while visiting a Whaling Chapel in New Bedford and viewing the memorial wall Ishmael makes reference to 'Secrets of the Goodwin Sands'.
 

Capt Popeye

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I would doubt that would be the case, as the bouyancy issue would still have to be overcome, which does not apply in the case of anyone disappearing down a land based sinkhole. The case of the American fisherman involved a breakthough into a large limestone cave network or a large dissolved salt dome, I cant remember which, and a whirlpool.
There are two possible sink hole locations I know of. There is " The Hole" at Stone Banks just off the Medusa Channel, and "The Mixon" just north of the Looe Channel. Both are only of a size that would consume a small vessel and there are no wreckage bits in the bottom that I have heard.. Both are very old and have a solid bottom. Until someone does a ground penetrating radar survey of the sandbanks, we will never know.
Hi there Mr H, yes well not sure if I expressed myself effectively, but I was thinking along the line of the Chalk layer beneath the Sand collapsing (like in the case of the Woman above) so that the sand actually drops into the void created by the Chalk hole, so any boat would not be sinking but swallowed up into the Chalk hole, the sand in that area just covering the Boat over; might then be possible for any time later on for that Boat to be thrust upwards and appear ontop of the Sand ? maybe ?
 

Leighb

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I would doubt that would be the case, as the bouyancy issue would still have to be overcome, which does not apply in the case of anyone disappearing down a land based sinkhole. The case of the American fisherman involved a breakthough into a large limestone cave network or a large dissolved salt dome, I cant remember which, and a whirlpool.
There are two possible sink hole locations I know of. There is " The Hole" at Stone Banks just off the Medusa Channel, and "The Mixon" just north of the Looe Channel. Both are only of a size that would consume a small vessel and there are no wreckage bits in the bottom that I have heard.. Both are very old and have a solid bottom. Until someone does a ground penetrating radar survey of the sandbanks, we will never know.
Where exactly is the sinkhole near Stone Banks, I have had a look at the chart and could not see any really deep holes.
 

Habebty

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Where exactly is the sinkhole near Stone Banks, I have had a look at the chart and could not see any really deep holes.
Having just checked the chart on my iPad, it’s not quite as “hole shaped“ as I thought, but still a deeper anomaly in a relatively flat area. See below - “The Well” near Armada mark.

C0CFF3BB-EF47-4797-99A6-D4923BC5CBC6.png
 
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