Topic ID #3143 - posted 3/23/2008 1:38 PM
davidbrinkman
Help dating an old Bridge Abutment
davidbrinkman
Hi all,
Back in 2004, I purchased a lot here in Columbia, SC on the Broad River about a mile above the city. During excavation, we discovered an old bridge abutment which has been verified by a couple of Archeologists. Over the last several years I’ve been doing research on the site and during a work sabbatical (last year) I put things together and I have the evidence on a web site ( http://www.dobrinkman.net/bridge/ ). The remains of this abutment may date back to the 1790s and may also be the abutment to the Confederate Bridge which was burned in 1865 in a failed attempt to stop General Sherman’s raid on Columbia. There is also a 1897 map that shows a bridge in this location. I guess the main question now is, is there a way to date the abutment? The abutment does have something that seems unique and I want to run this by experts to see what they think. Our State Archeologist seemed to think the structure would have been built after the civil war because he thought, prior to the civil war, it would not have been feasible to move such large boulders from a quarry to this location. A second Archeologist, however, said these size boulders could have been easily moved even during the late 1700s. So that takes me back to square one. Here’s what’s unique about these stones: About 6 of the granite boulders have 3 inch diameter holes drilled through them. One of them having a 5 foot long hole. All six boulders are placed directly below where the wood structure of the bridge would have come out from the abutment (the State Archeologist had a name for these and said these were used as ballast to hold the bridge down by running a rope or cable through the hole in the stone and then around the wood portion of the bridge). I also found a few boulders nearby that were split along the holes. The second Archeologist said that these holes were actually drilled at the quarry and that they were probably filled with powder and the stone was blown apart. The bridge builders took advantage of the boulders that had the holes still intact and used these under the bridge.
So, my question is, does this 3 inch diameter hole (drilled at a quarry) possibly date the cutting of the stone? I think I read that dynamite did not come into use until after the civil war. I’ve look at other old bridge abutments in the area and the holes I have found are much smaller than this and I know that dynamite would not require a hole anywhere near this size. Have any of you found/seen 3 inch holes like this and do you have any ideas of the date? I have attached a photo of the boulders with the holes and you can see this and other photos of the site at:
http://www.dobrinkman.net/bridge/evidence.htm
Thanks very much. I have recently submitted the preliminary paper work to have the site considered for the National Register of Historic Places. I’m hoping this will lead to further investigation and a future dig but our Archives and History State agency has been hit with budget cuts so I’m not sure how far this can go.
David Brinkman
Back in 2004, I purchased a lot here in Columbia, SC on the Broad River about a mile above the city. During excavation, we discovered an old bridge abutment which has been verified by a couple of Archeologists. Over the last several years I’ve been doing research on the site and during a work sabbatical (last year) I put things together and I have the evidence on a web site ( http://www.dobrinkman.net/bridge/ ). The remains of this abutment may date back to the 1790s and may also be the abutment to the Confederate Bridge which was burned in 1865 in a failed attempt to stop General Sherman’s raid on Columbia. There is also a 1897 map that shows a bridge in this location. I guess the main question now is, is there a way to date the abutment? The abutment does have something that seems unique and I want to run this by experts to see what they think. Our State Archeologist seemed to think the structure would have been built after the civil war because he thought, prior to the civil war, it would not have been feasible to move such large boulders from a quarry to this location. A second Archeologist, however, said these size boulders could have been easily moved even during the late 1700s. So that takes me back to square one. Here’s what’s unique about these stones: About 6 of the granite boulders have 3 inch diameter holes drilled through them. One of them having a 5 foot long hole. All six boulders are placed directly below where the wood structure of the bridge would have come out from the abutment (the State Archeologist had a name for these and said these were used as ballast to hold the bridge down by running a rope or cable through the hole in the stone and then around the wood portion of the bridge). I also found a few boulders nearby that were split along the holes. The second Archeologist said that these holes were actually drilled at the quarry and that they were probably filled with powder and the stone was blown apart. The bridge builders took advantage of the boulders that had the holes still intact and used these under the bridge.
So, my question is, does this 3 inch diameter hole (drilled at a quarry) possibly date the cutting of the stone? I think I read that dynamite did not come into use until after the civil war. I’ve look at other old bridge abutments in the area and the holes I have found are much smaller than this and I know that dynamite would not require a hole anywhere near this size. Have any of you found/seen 3 inch holes like this and do you have any ideas of the date? I have attached a photo of the boulders with the holes and you can see this and other photos of the site at:
http://www.dobrinkman.net/bridge/evidence.htm
Thanks very much. I have recently submitted the preliminary paper work to have the site considered for the National Register of Historic Places. I’m hoping this will lead to further investigation and a future dig but our Archives and History State agency has been hit with budget cuts so I’m not sure how far this can go.
David Brinkman
Post ID#6370 - replied 3/23/2008 1:58 PM
rkeyo
Moderator
Wow! Neat site and roads! As to dating the drill-holes, I would begin by calling a) working quarries and seeing if anyone has knowledge of historic quarrying techniques; b) the same for drilling equipment manufacturers; c) mining, engineering, quarrying, etc. museums. The holes clearly appear to be hand drilled, and thus may, indeed, be quite old. They also appear pretty weathered. As to dynamite, prior to it's invention, black powder was packed into holes, so being blasted does not necessarily make it post dynamite. In any case, have fun! 8-)
Post ID#6373 - replied 3/23/2008 5:31 PM
FireArch
Moderator
As for moving large cut stone prior to the 1700s lets ask the Egyptians, the Maya, the Inca, the Aztecs, the Olmecs, etc., etc. If these folks could have done it - and did - why would it not be possible in 18th C America?
Post ID#6375 - replied 3/23/2008 6:51 PM
davidbrinkman
Thanks FireArch and rkeyo. Our area is on the fall-line and we do still have a couple of active quarries in operation. I will take your advice and see if they have any history on prior operations. Thanks rkeyo for the age info. I have very strong historical evidence (General Assembly petitions, 1825 Mills Atlas, and an 1818 Court case) that points the 1790s bridge to our site. I wasn't sure how much (if any) was left of the original abutment but it sounds like much of what we see may date back to that. Proving the civil war bridge was here will be tougher because all the records from about 1830-1865 were burned by Sherman's men. The Confederates (in addition to setting the bridge on fire) also bombarded the bridge on our side with cannon fire. This is the only documented cannon firing in this area so finding fragments of civil war cannon balls would be a huge help. My neighbor downstream dug up (about 4 feet into the ground) a 5 inch civil war cannon ball. There should be much more in our area if this was the Confederate Bridge. Thanks again for you help. Every bit helps if I'm going to get local support for a dig.
David
David
Post ID#6377 - replied 3/23/2008 9:32 PM
FireArch
Moderator
Definitely try to look through historical photographs for your area as well. If you lucky enough to locate some, you might be able to use Prince's Principle to situate the bridge in the photo to present-day landscape, getting a sense of location, massing, various component elements, etc. (see http://en.wikipedia.org/wiki/Flowerdew_Hundred and http://etext.virginia.edu/flowerdew/Prince.html). I got to use it in Margie's (see wiki article) Cultural Landscape class, and as part of a colleague's MA thesis work. It's really cool to look through the camera with the photo filling in all the details of the landscape!
Good luck,
Richard
Good luck,
Richard
Post ID#6378 - replied 3/23/2008 9:57 PM
davidbrinkman
Thanks Richard. I just looked up "Prince's Principle" and this will be another good idea to apply. I did find an 1897 photo of the bridge which seems to match our landscape and "Prince's Principle" will be a more scientific way to show this. BTW, the caption on the 1897 photo states that this was the bridge burned when General Sherman came through.
Also, there is a well known 1865 illustration by William Waud of Sherman's crossing which shows his pontoon bridge and the burned remains of the bridge. Again, the landscape in the drawing seems to match our site and this is what first led me to the Confederate Bridge theory. I can also apply "Prince's Principle" to this. Thanks again for some more great advice. Below is William Wauds drawing. I will post my Prince's Principle results after I get a photo from the same angle/location as the 1865 Waud drawing.
Also, there is a well known 1865 illustration by William Waud of Sherman's crossing which shows his pontoon bridge and the burned remains of the bridge. Again, the landscape in the drawing seems to match our site and this is what first led me to the Confederate Bridge theory. I can also apply "Prince's Principle" to this. Thanks again for some more great advice. Below is William Wauds drawing. I will post my Prince's Principle results after I get a photo from the same angle/location as the 1865 Waud drawing.
Post ID#6380 - replied 3/24/2008 2:08 AM
FireArch
Moderator
That's the great thing about Prince's Principle; when done correctly it puts you within a meter or two of where the original photograph was taken, and the accompanying experience that that engenders is quite dramatic; when you realize that you could almost be in 1897, or whatever time period the photograph you are using was taken. Very cool.
In the case of my colleague's MA thesis work you could see the 20-stamp mill building, retaining walls, a bridge, rail line, houses, hotels, and people. It was entrancing.
In the case of my colleague's MA thesis work you could see the 20-stamp mill building, retaining walls, a bridge, rail line, houses, hotels, and people. It was entrancing.
Post ID#6386 - replied 3/24/2008 11:43 AM
timdig
I would suggest the following possibilities. Try contacting the Society for Industrial Archaeology. (http://www.siahq.org/) They have a number of members who specialize in bridges. There have been a number of articles in their journal about bridges. I would also search the HABS/HAER records and see if any bridges of similar technique or time period have been documented that you could use as comparative evidence. Hope this helps.
Post ID#6391 - replied 3/24/2008 2:46 PM
rkeyo
Moderator
Interesting drawing. It shows the bridge pilings as being dressed stone, but the stone in your pix, from the abutment, appears to be undressed, and therefore, possibly from an original, older structure. 8-)
Post ID#6392 - replied 3/24/2008 3:44 PM
davidbrinkman
I will look at http://www.siahq.org. Thanks. As for the dressed stone in the drawing, that's a good point about that being more modern than the abutment. It is very possible that our abutment is just the site of the 1790s bridge and many other documents show that a ferry also ran at this 1790s site before and after this bridge. This 1790s bridge used wood piers in the river. A unique thing about this site is that it has a nice steep drop that made it good for a bridge and then just a few feet away if has a very flat area that would have been good for a ferry. After the 1796 bridge fell apart in 1799, a ferry ran until 1829 when a nice bridge was built. I have a 1843 plat that shows the bridge 1/2 mile above our site which is where today's bridge is. It would seem logical that the 1865 bridge would have also been at this other site but there is other historical evidence that does not support this. Also, the large scale (1 mile = 1 inch) 1897 map shows it back at our site. In 1903 it's gone from our site (a dirt road is shown) and back at the other site. Nailing down the 1865 bridge has really been difficult. All records from that time were burned and almost no records exist from the reconstruction period. This may just be a case that can only be solved by a dig and maybe the discover of those cannon balls that hit the bridge in 1865.
One question about the dressed stone in the 1865 picture. Does anyone know how stones like this were held together? Should we be able to find any of the stones in the bottom of the river or would they have desolved away such that you could not tell they were cut stone? This river has taken down many bridges and only the concrete steel reinforced bridges have faired well. Thanks. I'm getting lots of good info here.
David
One question about the dressed stone in the 1865 picture. Does anyone know how stones like this were held together? Should we be able to find any of the stones in the bottom of the river or would they have desolved away such that you could not tell they were cut stone? This river has taken down many bridges and only the concrete steel reinforced bridges have faired well. Thanks. I'm getting lots of good info here.
David
Post ID#6393 - replied 3/24/2008 3:56 PM
scottyj432
Interesting point....the drawing definitely shows dressed stone and the stone in the photos are not dressed. That would seem to suggest the undressed stones date to an earlier period.
How wide is the river at this location?
Was there a ferry at this location as well or was it located elsewhere? Could these stones be associated with an early ferry...perhaps used as the anchor stones for the ferry cable?
Keep us posted on any further developments.
How wide is the river at this location?
Was there a ferry at this location as well or was it located elsewhere? Could these stones be associated with an early ferry...perhaps used as the anchor stones for the ferry cable?
Keep us posted on any further developments.
Post ID#6394 - replied 3/24/2008 4:57 PM
davidbrinkman
Prior to 1891 (when islands in the river were connected to form a canal on the other side of the river) I would say the river was about 925 feet wide and it is now about 1050 feet wide including the canal.
Originally, there was a one mile long island whose southern tip ended just below and across from the bridge abutment so the bridge could have taken advantage of the island for a pier. In the 1865 drawing, you can actually see the tip of an island below where the bridge crossed. By 1820 when the Mills Atlas was made, the 1790s bridge was gone but a road is shown going to the ferry on the Atlas (McGowan's Ferry Road). The road continues on the other side of the river just below the tip of the island which makes since for the ferry since it would have to go below the island. Many documents from 1791-1818 show that the ferry was at the same location as the 1790s bridge so some of these stones (with holes) that are in front of the abutment may have been anchors for the ferry.
We have also found lots of cable at the site that is mounted at a higher point but it seems to be directed down toward the river. The State Archeologist thought the cable would not be much older than 1900 so it may have been related to the bridge that was here in 1897. I've found another older looking metal cable (mostly buried) out from the abutment and running toward the river.
Do you know when metal cable came into use for things like ferries? Could metal cable go back as far as the ferry that ran here between 1799 and 1829? One document I have about this ferry mentioned that it used rope so I have assumed that this cable does not date back that far.
Below is a link to some pictures of the cables. The third picture is what was found between the stones and the river.
http://dobrinkman.net/columbiabridge/cable.htm
Thanks
David
Originally, there was a one mile long island whose southern tip ended just below and across from the bridge abutment so the bridge could have taken advantage of the island for a pier. In the 1865 drawing, you can actually see the tip of an island below where the bridge crossed. By 1820 when the Mills Atlas was made, the 1790s bridge was gone but a road is shown going to the ferry on the Atlas (McGowan's Ferry Road). The road continues on the other side of the river just below the tip of the island which makes since for the ferry since it would have to go below the island. Many documents from 1791-1818 show that the ferry was at the same location as the 1790s bridge so some of these stones (with holes) that are in front of the abutment may have been anchors for the ferry.
We have also found lots of cable at the site that is mounted at a higher point but it seems to be directed down toward the river. The State Archeologist thought the cable would not be much older than 1900 so it may have been related to the bridge that was here in 1897. I've found another older looking metal cable (mostly buried) out from the abutment and running toward the river.
Do you know when metal cable came into use for things like ferries? Could metal cable go back as far as the ferry that ran here between 1799 and 1829? One document I have about this ferry mentioned that it used rope so I have assumed that this cable does not date back that far.
Below is a link to some pictures of the cables. The third picture is what was found between the stones and the river.
http://dobrinkman.net/columbiabridge/cable.htm
Thanks
David
Post ID#6396 - replied 3/24/2008 5:35 PM
rkeyo
Moderator
I do love a good mystery! That said, the cable is probably relatively recent, as evidenced by the cable clip (also called a Crosby) in cable pic #2. If you look, you will likely find that the nuts holding it in place are hex nuts, suggesting a recent origin.
Another source of maps of your site might be the Corps of Engineers, the Army War College, West Point, or any university with a good collection of Civil War military maps. A call to the Dept. of Defense would probably get you other sources. My guess is that given the rather extensive pontoon bridge construction and the shelling by the Confederates (have you got a metal detector?), that there should be some pretty detailed maps that were used at the time. 8-)
Another source of maps of your site might be the Corps of Engineers, the Army War College, West Point, or any university with a good collection of Civil War military maps. A call to the Dept. of Defense would probably get you other sources. My guess is that given the rather extensive pontoon bridge construction and the shelling by the Confederates (have you got a metal detector?), that there should be some pretty detailed maps that were used at the time. 8-)
Post ID#6397 - replied 3/24/2008 5:57 PM
scottyj432
Twisted steel wire rope was invented in 1841 by John A. Roebling.
However, wire cables were used in some small bridge constructions (usually small foot bridges) from 1780 to the early 1800's. I do not know what kind of metal cable this was.
The first "large" bridge using wire cable in the construction was in Philly, PA in 1816.
Chains were also used at times.
I would suspect that ferries did not start using metal cables until perhaps later in the 1800's. It would have been a pretty expensive material for the typical ferry operator and rope would have been far cheaper. I may be completely wrong tho.
However, wire cables were used in some small bridge constructions (usually small foot bridges) from 1780 to the early 1800's. I do not know what kind of metal cable this was.
The first "large" bridge using wire cable in the construction was in Philly, PA in 1816.
Chains were also used at times.
I would suspect that ferries did not start using metal cables until perhaps later in the 1800's. It would have been a pretty expensive material for the typical ferry operator and rope would have been far cheaper. I may be completely wrong tho.
Post ID#6400 - replied 3/24/2008 7:04 PM
davidbrinkman
I wish I had joined Archaeology Fieldwork a couple of years back. I've never had so much good stuff come in just 24 hours. This is a great site and service. I really want to have this find preserved but for some reason it's a slow process getting local people involved. Our State newspaper did a story on this last year and it was the second most read story on a weekend when Obama and Clinton came into town. I thought that story would get things rolling but it didn't. I guess you just have to be patient.
rkeyo,
I have spent a lot of time looking for maps but you do list some sources that I have not tried. Thanks. I did find a copy of General Sherman's map of Columbia from 1865. Columbia sits at the convergence of 2 rivers. In 1865, there were 3 bridges. One on each river. The 1865 map does not have a scale on it but it shows each bridge to be equal distance from the convergence of the 2 rivers into one river. The other 2 bridges were also burned in 1865 and their abutments still exist and they are each one mile from the convergence. Historians have assumed that the third bridge (on our river) was all wood and that there were no abutments to be found. It turns out that our site is exactly one mile from the convergence! I have this map on the following page that documents all the Confederate Bridge evidence.
http://dobrinkman.net/bridge/1865.htm
scottyj432,
Great history on the cables. I'm sure this info will be useful when other visitors to the site come across this stuff and start asking questions.
You know, the cable with the Crosby clip may be something from the 1950s. Neighbors had a tale of a man who was starting to build a house here in the 1950s but he had a heart attack and died on the property. Some neighbors seemed a little superstitious of the site because of this. Well, last week I found the daughter of this man and it turned out that he did have a heart attack here but he died at the hospital. She told me that he worked for the railroad and that he had been moving some old railroad ties and bricks to the site but he had not started building anything yet. We found hundreds of manufactured bricks scattered around and one neighbor thought the man had started building steps down to the river with the old railroad ties. Maybe he was using this particular cable to move or hold those ties.
Thanks
David
rkeyo,
I have spent a lot of time looking for maps but you do list some sources that I have not tried. Thanks. I did find a copy of General Sherman's map of Columbia from 1865. Columbia sits at the convergence of 2 rivers. In 1865, there were 3 bridges. One on each river. The 1865 map does not have a scale on it but it shows each bridge to be equal distance from the convergence of the 2 rivers into one river. The other 2 bridges were also burned in 1865 and their abutments still exist and they are each one mile from the convergence. Historians have assumed that the third bridge (on our river) was all wood and that there were no abutments to be found. It turns out that our site is exactly one mile from the convergence! I have this map on the following page that documents all the Confederate Bridge evidence.
http://dobrinkman.net/bridge/1865.htm
scottyj432,
Great history on the cables. I'm sure this info will be useful when other visitors to the site come across this stuff and start asking questions.
You know, the cable with the Crosby clip may be something from the 1950s. Neighbors had a tale of a man who was starting to build a house here in the 1950s but he had a heart attack and died on the property. Some neighbors seemed a little superstitious of the site because of this. Well, last week I found the daughter of this man and it turned out that he did have a heart attack here but he died at the hospital. She told me that he worked for the railroad and that he had been moving some old railroad ties and bricks to the site but he had not started building anything yet. We found hundreds of manufactured bricks scattered around and one neighbor thought the man had started building steps down to the river with the old railroad ties. Maybe he was using this particular cable to move or hold those ties.
Thanks
David
Post ID#6402 - replied 3/24/2008 8:56 PM
scottyj432
Well, I must say I am intrigued by the mystery of your large quarried stones with the holes drilled in them.
So, after a fair amount of pondering and snooping around on the internet, here is what I think you may have:
In all likelihood the 1790's era bridge was constructed of wood pilings driven into the river with an overlying wood deck stretched between the several wood pilings. It is unlikely these pilings would have been treated against decay, tho it was possible to do so at that date. In that time period a common method was to treat the wood with mercury chloride; a somewhat expensive method. It was not until 1838 that the much simpler and cheaper method of injecting creosote into wood was developed on a large scale in this country.
At that time period it was possible to construct stone masonry pilings, but depending on the depth of the waterway and the current, it could be logistically difficult. One method of accomplishing the placement of stone masonry pilings across a wide river was to construct the pilings and then during the winter when the river had frozen over with thick ice, the pilings were hauled out onto the ice and put into position and then when the ice melted, they dropped into place. How this was done with any precision, I do not know. The Burr Bridge in upstate New York was constructed with this method in (I think) 1806 across the Mohawk River (I think it was the Mohawk).
Anyway, it seems more likely the 1790's era bridge was constructed using wood pilings and those wood pilings were most likely untreated against decay. Given the width of the river, the bridge was probably somewhat unstable due to the river current and the seasonal floodings. If the wood pilings were untreated, decay would also contribute to the instability. Longer spanning wood-pile bridges were sometimes reinforced with metal cables. These metal cables (or chains) were in some fashion attached to the bridge and either end of the cables or chains were secured to each bank and then tightened to add stability to the structure.
Judging from your photos and from the drawing of Sherman's crossing, it does not appear there are natural rock outcroppings at this location that may have served as the anchor for the cable/chains. Also, the trees in the drawing do not appear to be large enough to have served any useful purpose in that regard. So, if a cable/chain type of reinforcement was used on the early bridge, that may well explain the large quarried stone with the drilled holes located on each side of the river. The cable/chains were then in some way attached to those stones and then in some fashion they were tightened to try and give some stability to the bridge from the force of the river current/floods.
Anyway, that is my theory.
Scott
So, after a fair amount of pondering and snooping around on the internet, here is what I think you may have:
In all likelihood the 1790's era bridge was constructed of wood pilings driven into the river with an overlying wood deck stretched between the several wood pilings. It is unlikely these pilings would have been treated against decay, tho it was possible to do so at that date. In that time period a common method was to treat the wood with mercury chloride; a somewhat expensive method. It was not until 1838 that the much simpler and cheaper method of injecting creosote into wood was developed on a large scale in this country.
At that time period it was possible to construct stone masonry pilings, but depending on the depth of the waterway and the current, it could be logistically difficult. One method of accomplishing the placement of stone masonry pilings across a wide river was to construct the pilings and then during the winter when the river had frozen over with thick ice, the pilings were hauled out onto the ice and put into position and then when the ice melted, they dropped into place. How this was done with any precision, I do not know. The Burr Bridge in upstate New York was constructed with this method in (I think) 1806 across the Mohawk River (I think it was the Mohawk).
Anyway, it seems more likely the 1790's era bridge was constructed using wood pilings and those wood pilings were most likely untreated against decay. Given the width of the river, the bridge was probably somewhat unstable due to the river current and the seasonal floodings. If the wood pilings were untreated, decay would also contribute to the instability. Longer spanning wood-pile bridges were sometimes reinforced with metal cables. These metal cables (or chains) were in some fashion attached to the bridge and either end of the cables or chains were secured to each bank and then tightened to add stability to the structure.
Judging from your photos and from the drawing of Sherman's crossing, it does not appear there are natural rock outcroppings at this location that may have served as the anchor for the cable/chains. Also, the trees in the drawing do not appear to be large enough to have served any useful purpose in that regard. So, if a cable/chain type of reinforcement was used on the early bridge, that may well explain the large quarried stone with the drilled holes located on each side of the river. The cable/chains were then in some way attached to those stones and then in some fashion they were tightened to try and give some stability to the bridge from the force of the river current/floods.
Anyway, that is my theory.
Scott
Post ID#6405 - replied 3/24/2008 10:35 PM
davidbrinkman
Scottyj,
I think you have correctly described the early version of this bridge. Here's some more history... In 1791, 2 bridges were built. The first bridge was built by Wade Hampton (the grandfather of Wade Hampton III who would be a Confederate General and the Governor of South Carolina). John Compty would follow him in 1791 and build his first bridge across our river. It is documented that Hampton always used wood piers in the river that were mounted to the riverbed with 1.5" anchor bolts. The Compty and Hampton bridges were both lost in a flood in 1792. They were both rebuilt and lost in another flood in 1794. Both were rebuilt a third time in 1796. Hampton lost his again shortly after this but Compty's third bridge survived. Compty, however, died in 1799. Hampton would lose his forth and final bridge in 1799. It is documented that Compty's bridge started falling apart in 1799 (maybe untreated wood and no one left to repair it). Compty's widow remarried that year to a man named McGowan and the McGowan’s were able to get a charter for a ferry at the site of the bridge.
A few months back, I discovered a second abutment in my neighbor's back yard. It did not have the anchor type boulders but I did find 1.5" anchor bolt holes on the other side of the river. Below are these photos:
I think this second abutment may be the site of Compty's first and second bridges. Why did his first bridge out live Hampton's third bridge? I think Compty's third bridge was at our site which was 6 feet higher and he used the anchor boulders instead of iron anchor bolts (no anchor bolt holes were found in the area of our site). Also, just like you theorized, I found an iron object in a river rock (which is often under water) that is shaped in a way that would be ideal for tying a rope/cable/chain to. Its position, relative to the bridge, is about 30 degrees from where the bridge would cross and about 50 feet into the river. It is shown in the photo below:
Let me know what you think about this object. When I first came across it, I was sure it was man-made until I thumped it with my finger. It gave a ceramic sound and just didn't seem to have the density of iron. I returned with my metal detector and it gave a strong reading of iron. I scanned the entire area around this and my detector did not find any other metals. Could it be that this iron object just has a low density because it is so old and has been underwater much of this time?
About the level of the water: it was also well documented by the Union Army that there had been major flooding in South Carolina prior to Sherman's march into the state and that the rivers were very high. I think the civil war drawing shows this. Normally, here in the fall-line, we have a good number of exposed rocks just above and below our site. There is a nice narrow clear path, however, from our site to the opposite site that would have been good for a ferry even in low water conditions.
Thanks
David
I think you have correctly described the early version of this bridge. Here's some more history... In 1791, 2 bridges were built. The first bridge was built by Wade Hampton (the grandfather of Wade Hampton III who would be a Confederate General and the Governor of South Carolina). John Compty would follow him in 1791 and build his first bridge across our river. It is documented that Hampton always used wood piers in the river that were mounted to the riverbed with 1.5" anchor bolts. The Compty and Hampton bridges were both lost in a flood in 1792. They were both rebuilt and lost in another flood in 1794. Both were rebuilt a third time in 1796. Hampton lost his again shortly after this but Compty's third bridge survived. Compty, however, died in 1799. Hampton would lose his forth and final bridge in 1799. It is documented that Compty's bridge started falling apart in 1799 (maybe untreated wood and no one left to repair it). Compty's widow remarried that year to a man named McGowan and the McGowan’s were able to get a charter for a ferry at the site of the bridge.
A few months back, I discovered a second abutment in my neighbor's back yard. It did not have the anchor type boulders but I did find 1.5" anchor bolt holes on the other side of the river. Below are these photos:
I think this second abutment may be the site of Compty's first and second bridges. Why did his first bridge out live Hampton's third bridge? I think Compty's third bridge was at our site which was 6 feet higher and he used the anchor boulders instead of iron anchor bolts (no anchor bolt holes were found in the area of our site). Also, just like you theorized, I found an iron object in a river rock (which is often under water) that is shaped in a way that would be ideal for tying a rope/cable/chain to. Its position, relative to the bridge, is about 30 degrees from where the bridge would cross and about 50 feet into the river. It is shown in the photo below:
Let me know what you think about this object. When I first came across it, I was sure it was man-made until I thumped it with my finger. It gave a ceramic sound and just didn't seem to have the density of iron. I returned with my metal detector and it gave a strong reading of iron. I scanned the entire area around this and my detector did not find any other metals. Could it be that this iron object just has a low density because it is so old and has been underwater much of this time?
About the level of the water: it was also well documented by the Union Army that there had been major flooding in South Carolina prior to Sherman's march into the state and that the rivers were very high. I think the civil war drawing shows this. Normally, here in the fall-line, we have a good number of exposed rocks just above and below our site. There is a nice narrow clear path, however, from our site to the opposite site that would have been good for a ferry even in low water conditions.
Thanks
David
Post ID#6407 - replied 3/25/2008 10:37 AM
Dmack89
I see you have gotten a lot of good responses - But have you tried forums where you might actually find bridge engineers and folks with an established interest in the history of engineering? They may have even better answers for you.
I have never contacted them myself, but a quick google search found the following site that might be helpful:
http://bridgepros.com/ - a site dedicated to the Engineering, History & Construction of Bridges
many more were listed - good luck.
DM
I have never contacted them myself, but a quick google search found the following site that might be helpful:
http://bridgepros.com/ - a site dedicated to the Engineering, History & Construction of Bridges
many more were listed - good luck.
DM
Post ID#14122 - replied 6/1/2009 6:18 PM
davidbrinkman
What a difference a year can make. A few months after my first post, an amazing 1870 12 foot long survey (200" to the inch) was donated to the South Carolina Archives. I came across it and it ruled out my back yard as the Confederate Bridge site. I sent my story to PBS' History Detectives and they came to investigate. The South Carolina State Archaeologist and other important local Historians got involved and the Civil war case was solved. The show will appear on PBS' History Detectives on September 7, 2009. As for my back yard, by a process of elimination, this may be the 1796 bridge site. It will take a lot of Archaeology work to prove this. Thanks to all that helped.
Post ID#14123 - replied 6/1/2009 6:22 PM
FireArch
Moderator
David, that's awesome, good job man!
Cant wait to see the show. Be sure to send a reminder before it airs.
Cheers,
Richard
Cant wait to see the show. Be sure to send a reminder before it airs.
Cheers,
Richard
Post ID#14127 - replied 6/2/2009 10:32 AM
scottyj432
That is great news on the bridge! I love History Detectives and cannot wait to see the show. Definitely post a reminder here as the airing time draws near.
Scott
Scott
Post ID#14156 - replied 6/7/2009 12:58 PM
rkeyo
Moderator
Kool! 8-)
Post ID#15239 - replied 9/2/2009 4:49 PM
davidbrinkman
You can see the conclusion of this case on the season finale of PBS History Detectives on Labor Day (Sept 7) at 9PM EST (8PM CST) on your local PBS station. The segment is called "Civil War Bridge". It was a blast doing the show and, in a new area for History Detectives, the case is proven with some Archaeology Field Work.
You can see more about the show at:
http://www.pbs.org/opb/historydetectives/investigations/711_bridge.html
Thanks again for everyone that helped me here at archaeologyfieldwork.com
David
You can see more about the show at:
http://www.pbs.org/opb/historydetectives/investigations/711_bridge.html
Thanks again for everyone that helped me here at archaeologyfieldwork.com
David
Post ID#15265 - replied 9/3/2009 9:57 PM
scottyj432
I can't wait to see the show.
Scott
Scott
Post ID#15279 - replied 9/4/2009 1:15 PM
FireArch
Moderator
Me too. I've sent out emails and linked it to facebook. Cant wait to find out the answer.
Post ID#15311 - replied 9/8/2009 2:12 AM
FireArch
Moderator
Man that was awesome! Everyone did a fantastic job (it was interesting to see Elyse's reaction to various bits of info, esp the survey results - she always seemed to be in disbelief or doubt of claim). Having the state archaeologist run magnetic surveys was just too much. I doubt you'd get that kind of response out here.
Great job David, and congratulations on the award and the opportunity to correct the historical record.
Cheers,
Richard
Great job David, and congratulations on the award and the opportunity to correct the historical record.
Cheers,
Richard
Post ID#15314 - replied 9/8/2009 6:11 PM
davidbrinkman
Thanks FireArch. The State Archaeologist, Museum, and the Archives guy had all done History Detectives shows before and were impressed by HD so they were all excited about doing this. That made a big difference. The largest newspaper in South Carolina had also been following this case so there was already some local interest which helped even more. It was just a great positive thing all the way around. All those transition scenes you see in the show with reenactors were filmed just for this show with local reenactors. These guys put a lot of money into their hooby and they were so proud of the show that they offered to help pay for the new Historical Marker. An amazing project.
Post ID#15325 - replied 9/10/2009 11:42 AM
davidbrinkman
For those that missed the show, you can view it on the PBS video portal at:
http://video.pbs.org/video/1237365939
http://video.pbs.org/video/1237365939
Post ID#15326 - replied 9/10/2009 3:36 PM
FireArch
Moderator
Excellent.
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