[JenBurdoo] How not to sink

[JenBurdoo]

During the American Civil War, a US Navy expedition to Roanoke Island was blocked by a sandbar six feet below the surface of the water. Most of the ships drew eight feet of water. How did they cross the sandbar?

[GalFisk]

Lighten the ship? Change the ship? Change the sandbar? Did ships cross the sandbar? Did they use ships with shallower draft? WAG: Did everyone run aft, lifting the bow so that it could go over the sandbar, and then everybody ran forward, tipping the boat so the stern could go over?

[JenBurdoo]

Lighten the ship? No. Change the ship? No. Change the sandbar? Yes. Did ships cross the sandbar? Yes. Did they use ships with shallower draft? No. WAG: Did everyone run aft, lifting the bow so that it could go over the sandbar, and then everybody ran forward, tipping the boat so the stern could go over? No, the sandbar was too wide for that.

[Sundowner]

As there is not a big difference between 6 and 8 feet -- are tides relevant? Did they simply wait until high tide to pass the sandbar? or, on the contrary, wait until low tide and shoveled away the sand? (I think if the water goes back to 5 or 4 feet, tall men could stand there and work with the shovel)
One more idea: Given the strange nature of the Pamlico sound, did they build dams on the rivers feeding the sound, and then open the dams and the water flooding in would give the ship the additional two feet?

[GalFisk]

Was the sand bar: exploded? Lowered? Channeled? Removed? Was it changed by humans? Nature? Animals? Did they make a groove in it, and let currents or tides widen it?

[JenBurdoo]

As there is not a big difference between 6 and 8 feet -- are tides relevant? No. Did they simply wait until high tide to pass the sandbar? or, on the contrary, wait until low tide and shoveled away the sand? (I think if the water goes back to 5 or 4 feet, tall men could stand there and work with the shovel) Not shallow or deep enough for either.
One more idea: Given the strange nature of the Pamlico sound, did they build dams on the rivers feeding the sound, and then open the dams and the water flooding in would give the ship the additional two feet? Interesting WAG, but no.

Was the sand bar: exploded? Lowered? Channeled? This. Removed? Was it changed by humans? This. Nature? And this. Animals? Did they make a groove in it, and let currents or tides widen it? Yes. How?

[biograd]

Did they build a structure that diverted natural water flow toward a particular spot along the sand bar, concentrating the flow there?

[JenBurdoo]

Did they build a structure that diverted natural water flow toward a particular spot along the sand bar, concentrating the flow there?

Something like that, though I'm not sure the terms "structure" or "diverted" apply. Explore.

[GalFisk]

Enemy action relevant? Did they trick the enemy into sinking something in just the right place? Did they make a groove by dragging something? Ramming it? Using a ship? More than one? Some other vessel?

[Mimino]

Did they dump more sand on the sandbar, except for a small space of 20 yards where the ship could pass through?
So that all the tidal current went through that narrow space and washed out the sand?

[JenBurdoo]

Enemy action relevant? No. Did they trick the enemy into sinking something in just the right place? No. Did they make a groove by dragging something? Ramming it? This. Using a ship? Yes. More than one? Yope. Some other vessel? And yes.

Did they dump more sand on the sandbar, except for a small space of 20 yards where the ship could pass through?
So that all the tidal current went through that narrow space and washed out the sand? No, but an interesting guess. I'm sure they hadn't the equipment needed for such a project, at least..

[biograd]

Did they run another ship aground on one part of the sand bar, creating a barrier that forced the tidal current to go around it and wash away the sand elsewhere?

[JenBurdoo]

Did they run another ship aground on one part of the sand bar, Yes. creating a barrier that forced the tidal current to go around it and wash away the sand elsewhere? No.

[Mimino]

Was this ship (the one that was set aground) ever removed from this place? backward? forward?
WAG: Did they remove the stern of the ship after setting it aground, so that the tide would push it through the sandbar?

[JenBurdoo]

Was this ship (the one that was set aground) ever removed from this place? Yes. backward? forward? This.
WAG: Did they remove the stern of the ship after setting it aground, so that the tide would push it through the sandbar? No.

[GalFisk]

Was the ship that ran aground built or modified in order to cause or enhance the channeling effect?

[JenBurdoo]

Was the ship that ran aground built or modified in order to cause or enhance the channeling effect? No.

[GalFisk]

Is it correct that one ship and one other vessel rammed the sand bar? Were there people on the ship when the ramming happened? On the other vessel? Relevant what type of ship it was?

[Sundowner]

As it was in the 1860s: the ships were probably sailing ships? or maybe steamers?
Was one of the ships a paddle steamer? did they use the paddles to move the sand?
Was one of the ships a submarine?
Were a lot of people on the ship when they set it aground? and then the people went back to the other ship? so that the ship startet to float again and could be pulled back and rammed into the sand again?

[JenBurdoo]

Is it correct that one ship and one other vessel rammed the sand bar? No. Were there people on the ship when the ramming happened? Yes, likely a reduced crew. On the other vessel? Yes. Relevant what type of ship it was? Only that the first was large, but yes to the other.

As it was in the 1860s: the ships were probably sailing ships? or maybe steamers? Assume this.
Was one of the ships a paddle steamer? did they use the paddles to move the sand? No to both.
Was one of the ships a submarine? No.
Were a lot of people on the ship when they set it aground? and then the people went back to the other ship? so that the ship started to float again and could be pulled back and rammed into the sand again? No, this wasn't the method used,

[JenBurdoo]

Hint: If you've ever walked on the beach, you've seen this effect in action.

[Mimino]

Did they approach the island from the sea (i.e. from the South)? or from the river (i.e. from the North)?
Did the sandbar go all around the island? Would it have been possible to circumvent the sandbar?
Was the sandbar right perpendicular to the tidal current?
Or maybe somewhat tilted? in that case the current would anyway wash away some sand from the side that is exposed to the current and deposit it at the end of the sandbar. Is this relevant?
Was the ship rammed into the sandbar in order to increase the surface that was exposed to the current? (should then have been perpendicular to the sandbar in order to have the best effect)
Was the ship pushed over the sandbar by its own engine? by the other ship? by the current?

[JenBurdoo]

Did they approach the island from the sea (i.e. from the South)? This. or from the river (i.e. from the North)?
Did the sandbar go all around the island? Irr. Would it have been possible to circumvent the sandbar? Assume no.
Was the sandbar right perpendicular to the tidal current? Yes.
Or maybe somewhat tilted? No. in that case the current would anyway wash away some sand from the side that is exposed to the current and deposit it at the end of the sandbar. Is this relevant? No.
Was the ship rammed into the sandbar in order to increase the surface that was exposed to the current? (should then have been perpendicular to the sandbar in order to have the best effect) Yes.
Was the ship pushed over the sandbar by its own engine? by the other ship? by the current? None of these.