Do fundo do mar... Sea bottom
Wednesday, March 23, 2005
Collapsed riverbank exposes host of sunken vessels
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Dateline Alabama
By Mark Schleifstein
March 20, 2005
A section of the Mississippi riverbank near Audubon Park collapsed about a year and a half ago, with astonishing results.
No, muddy water did not inundate Uptown New Orleans. Riverbank repairs are a routine task that the Army Corps of Engineers performs adeptly. What made this job special was the historical treasure trove it turned up: 19 sunken ships, including the remains of a Civil War ironclad that played a major role in the 1864 battle of Mobile Bay.
Research conducted for the corps provides a rich and unusual view of the ties between a sliver of Uptown - the area just upriver from the Audubon Park Butterfly - and the economic and cultural heritage of the city and the nation. This was the place where renowned African-American singer Mahalia Jackson grew up; where ferries transported horse-drawn carriages, automobiles, and railroad cars and engines across the Mississippi; and where many of the work ships servicing the Port of New Orleans, the river and ocean-going shipping were based.
The sunken ships, scattered along about a mile of sloping underwater riverbank that's 30 to 150 feet deep, are mostly the derelict remains of vessels used by various Bisso family businesses that have operated in the area since at least 1853. And it was Bisso workers who first spotted the collapsing riverbank about 18 months ago.
"We lost about 50 feet of land," remembered W.A. "Cappy" Bisso III, chairman of Bisso Marine, one of the Bisso companies along the river at the repair site. "It was there when everybody went home that night and wasn't there the next morning."
When it became clear that at least two of the shipwrecks had historical value and should be protected, the corps quickly jettisoned its normal riverbank repair process, which uses huge revetment mats made of concrete panels to armor failing banks. Instead, the riverbank is being repaired with more than 140,000 tons of rock at a cost of $2.1 million to ensure that the Mississippi's current doesn't undercut that portion of the levee protecting the Carrollton-Riverbend area of New Orleans.
"The idea is to preserve them in place as best we can," said Don Rawson, a corps civil engineer directing the repair, said of the submerged hulls. "We're not placing rocks around the two most critical vessels."
The sunken ships were spotted by corps researchers using sidescan sonar and multibeam bathymetry to survey the underwater portion of the east bank of the river. Projecting multiple sound beams along the river's floor provided a three-dimensional image of the outlines of individual ships, and even of pilings driven through one of the ships.
The vessels lie along the east bank of the river from Audubon Park to Lowerline Street.
Using sophisticated sonar tools and old-fashioned hard-hat divers, archaeologists working for the corps used a variety of public and private business records and the reminiscences of Bisso officials to identify many of the ships and explain their roles in the port's history.
Among the discoveries documented in a two-volume report prepared for the corps by R. Christopher Goodwin & Associates are the remains of a tall-sailed schooner, several river or ocean-going tugs, a number of work and derrick barges, and at least two ferries that once traveled between Algiers and the Walnut Street wharf.
The area is marked on river charts as Greenville Bend, a reference to the adjacent Faubourg Greenville, a pie-shaped piece of land stretching toward Lake Pontchartrain from the river that was sandwiched between New Orleans and the village of Carrollton, until both were annexed by the city in the late 1800s.
Much of the land once had been used to raise indigo and sugarcane before it was subdivided for homes and businesses. During the Civil War, part of the land was used as a Union garrison, and nearby stables were used after the war by an African-American cavalry detachment that was the forerunner of the famed Buffalo Soldiers.
The most important find doesn't look so important in the underwater sonar views, but the shadowlike image that looks like a square picket fence emerging from the river bottom is the remains of the USS Chickasaw, an ironclad built in St. Louis in 1864 by James B. Eads.
Archaeologist Christopher Goodwin said there's not much chance any of the shipwrecks will be raised because the cost would outweigh the ships' historical value.
"Because of the history of refits of the Chickasaw, it's really the history of the vessel that's important, and that history already is fairly well-documented," he said. "The only reason to bring it up would be if the repair project would have a direct adverse effect on it and any historical data would be lost, and even then, only if something good could be done with it.
"It would cost millions to stabilize and restore, and at the end of the day, you'd have a vessel that's been cut up, chopped up and has lost its integrity above the hull," Goodwin said.
The Chickasaw is not the only Civil War-era ship caught in such limbo in the state, he said. "The CSS Louisiana is in Plaquemines Parish underneath a levee and a lot of water," and another ironclad is in the Red River at Bossier City.
Cappy Bisso said his company also has no interest in raising the Chickasaw, even though it specializes in raising sunken ships. "Only if somebody wanted to pay for it," he said.
In 1964, the company helped federal officials recover the USS Cairo, another ironclad now on display at Vicksburg National Historical Park. The sunken Boaz was one of the crane barges used in that effort.
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Dateline Alabama
By Mark Schleifstein
March 20, 2005
A section of the Mississippi riverbank near Audubon Park collapsed about a year and a half ago, with astonishing results.
No, muddy water did not inundate Uptown New Orleans. Riverbank repairs are a routine task that the Army Corps of Engineers performs adeptly. What made this job special was the historical treasure trove it turned up: 19 sunken ships, including the remains of a Civil War ironclad that played a major role in the 1864 battle of Mobile Bay.
Research conducted for the corps provides a rich and unusual view of the ties between a sliver of Uptown - the area just upriver from the Audubon Park Butterfly - and the economic and cultural heritage of the city and the nation. This was the place where renowned African-American singer Mahalia Jackson grew up; where ferries transported horse-drawn carriages, automobiles, and railroad cars and engines across the Mississippi; and where many of the work ships servicing the Port of New Orleans, the river and ocean-going shipping were based.
The sunken ships, scattered along about a mile of sloping underwater riverbank that's 30 to 150 feet deep, are mostly the derelict remains of vessels used by various Bisso family businesses that have operated in the area since at least 1853. And it was Bisso workers who first spotted the collapsing riverbank about 18 months ago.
"We lost about 50 feet of land," remembered W.A. "Cappy" Bisso III, chairman of Bisso Marine, one of the Bisso companies along the river at the repair site. "It was there when everybody went home that night and wasn't there the next morning."
When it became clear that at least two of the shipwrecks had historical value and should be protected, the corps quickly jettisoned its normal riverbank repair process, which uses huge revetment mats made of concrete panels to armor failing banks. Instead, the riverbank is being repaired with more than 140,000 tons of rock at a cost of $2.1 million to ensure that the Mississippi's current doesn't undercut that portion of the levee protecting the Carrollton-Riverbend area of New Orleans.
"The idea is to preserve them in place as best we can," said Don Rawson, a corps civil engineer directing the repair, said of the submerged hulls. "We're not placing rocks around the two most critical vessels."
The sunken ships were spotted by corps researchers using sidescan sonar and multibeam bathymetry to survey the underwater portion of the east bank of the river. Projecting multiple sound beams along the river's floor provided a three-dimensional image of the outlines of individual ships, and even of pilings driven through one of the ships.
The vessels lie along the east bank of the river from Audubon Park to Lowerline Street.
Using sophisticated sonar tools and old-fashioned hard-hat divers, archaeologists working for the corps used a variety of public and private business records and the reminiscences of Bisso officials to identify many of the ships and explain their roles in the port's history.
Among the discoveries documented in a two-volume report prepared for the corps by R. Christopher Goodwin & Associates are the remains of a tall-sailed schooner, several river or ocean-going tugs, a number of work and derrick barges, and at least two ferries that once traveled between Algiers and the Walnut Street wharf.
The area is marked on river charts as Greenville Bend, a reference to the adjacent Faubourg Greenville, a pie-shaped piece of land stretching toward Lake Pontchartrain from the river that was sandwiched between New Orleans and the village of Carrollton, until both were annexed by the city in the late 1800s.
Much of the land once had been used to raise indigo and sugarcane before it was subdivided for homes and businesses. During the Civil War, part of the land was used as a Union garrison, and nearby stables were used after the war by an African-American cavalry detachment that was the forerunner of the famed Buffalo Soldiers.
The most important find doesn't look so important in the underwater sonar views, but the shadowlike image that looks like a square picket fence emerging from the river bottom is the remains of the USS Chickasaw, an ironclad built in St. Louis in 1864 by James B. Eads.
Archaeologist Christopher Goodwin said there's not much chance any of the shipwrecks will be raised because the cost would outweigh the ships' historical value.
"Because of the history of refits of the Chickasaw, it's really the history of the vessel that's important, and that history already is fairly well-documented," he said. "The only reason to bring it up would be if the repair project would have a direct adverse effect on it and any historical data would be lost, and even then, only if something good could be done with it.
"It would cost millions to stabilize and restore, and at the end of the day, you'd have a vessel that's been cut up, chopped up and has lost its integrity above the hull," Goodwin said.
The Chickasaw is not the only Civil War-era ship caught in such limbo in the state, he said. "The CSS Louisiana is in Plaquemines Parish underneath a levee and a lot of water," and another ironclad is in the Red River at Bossier City.
Cappy Bisso said his company also has no interest in raising the Chickasaw, even though it specializes in raising sunken ships. "Only if somebody wanted to pay for it," he said.
In 1964, the company helped federal officials recover the USS Cairo, another ironclad now on display at Vicksburg National Historical Park. The sunken Boaz was one of the crane barges used in that effort.
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