Cumnock Railroad Bridges - Revision history

Matthew at 15:14, 14 November 2020

2020-11-14T15:14:37Z

← Older revision		Revision as of 15:14, 14 November 2020
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	The single-span truss bridge continues to carry trains, while the two-span one in the background has been abandoned for quite some time. The trestle approaches leading up to the in-use bridge use modern steel i-beam columns as opposed to pine ones, indicating that it still carries a good amount of rail traffic. The disused bridge, in contrast, has been taken over in many spots by thick vines. Interestingly, the abandoned bridge has less rust on it than its companion.		The single-span truss bridge continues to carry trains, while the two-span one in the background has been abandoned for quite some time. The trestle approaches leading up to the in-use bridge use modern steel i-beam columns as opposed to pine ones, indicating that it still carries a good amount of rail traffic. The disused bridge, in contrast, has been taken over in many spots by thick vines. Interestingly, the abandoned bridge has less rust on it than its companion.

	The in-use bridge (hereafter referred to as the "downstream" bridge, despite being north of its abandoned counterpart) once carried the main line of the original Norfolk Southern Railway (like the nearby [[Norfolk Southern Cape Fear River Bridge]]), a distinct railroad from the corporate entity of today. The abandoned downstream bridge carried the Atlantic and Yadkin Railway, which ran northwest from Sanford to Greensboro. Both railroads were eventually acquired by the Southern Railway. At some point in history, either the Southern or its successor, the current Norfolk Southern, chose to consolidate the lightly-used crossing into a single bridge and subsequently abandoned the A&Y bridge.		The in-use bridge (hereafter referred to as the "downstream" bridge, despite being north of its abandoned counterpart) was built by the Phoenix Bridge Company in 1912. It once carried the main line of the original Norfolk Southern Railway (like the nearby [[Norfolk Southern Cape Fear River Bridge]]), a distinct railroad from the corporate entity of today. The bridge was constructed when the main line was extended to Charlotte[https://www.american-rails.com/original.html]. The abandoned downstream bridge carried the Atlantic and Yadkin Railway, which ran northwest from Sanford to Greensboro. Both railroads were eventually acquired by the Southern Railway. At some point in history, either the Southern or its successor, the current Norfolk Southern, chose to consolidate the lightly-used crossing into a single bridge and subsequently abandoned the A&Y bridge.

	Both of these structures utilize the Warren truss configuration, as indicated by the "W" pattern formed by their diagonal members. Each employs riveted gusset plate connections. These two features, along with the presence of I-beam members (as opposed to ones "stitched" together using small pieces of steel such as v-lacing), place the construction dates of both most likely within the first half of the twentieth century.		Both of these structures utilize the Warren truss configuration, as indicated by the "W" pattern formed by their diagonal members. Each employs riveted gusset plate connections. These two features, along with the presence of I-beam members (as opposed to ones "stitched" together using small pieces of steel such as v-lacing), place the construction dates of both most likely within the first half of the twentieth century.

	The downstream bridge is a Polygonal Warren truss, distinguished by the semi-arched shape to the top chord. Since the top chord has exactly three sections to it (or four angles), the bridge could also be considered a Camelback Warren, not to be confused with a true camelback such as the one to the northeast (which is based off the Pratt truss). There is a great deal of variety to the structural members of this bridge, demonstrating the amount of complex engineering its design required. The two diagonal members that point inward (the ones that run parallel to the front posts) are of a heavier construction than the others, with thicker beams that are stitched together using latticing. The innermost diagonals (the ones that form a "v" in the center of the span) are smaller and are stitched together using v-lacing, while the remaining four diagonals are simple i-beams. The vertical members that connect with diagonals on the top are solid i-beams, while those that connect on the bottom are stitched together. The bracing the connects the two trusses together at the top employs latticing ("x-ing"). The bridge is similar in design to a smaller one that crosses NC 87 in Burlington. One notable shared feature is the "W" pattern of the bracing at each bridge's portal~~. The Burlington structure was built by the Carolina Steel and Iron Company, which may or may not have erected this larger example~~.		The downstream bridge is a Polygonal Warren truss, distinguished by the semi-arched shape to the top chord. Since the top chord has exactly three sections to it (or four angles), the bridge could also be considered a Camelback Warren, not to be confused with a true camelback such as the one to the northeast (which is based off the Pratt truss). There is a great deal of variety to the structural members of this bridge, demonstrating the amount of complex engineering its design required. The two diagonal members that point inward (the ones that run parallel to the front posts) are of a heavier construction than the others, with thicker beams that are stitched together using latticing. The innermost diagonals (the ones that form a "v" in the center of the span) are smaller and are stitched together using v-lacing, while the remaining four diagonals are simple i-beams. The vertical members that connect with diagonals on the top are solid i-beams, while those that connect on the bottom are stitched together. The bracing the connects the two trusses together at the top employs latticing ("x-ing"). The bridge is similar in design to a smaller one that crosses NC 87 in Burlington. One notable shared feature is the "W" pattern of the bracing at each bridge's portal.

	The upstream bridge is also an atypical Warren, perhaps even more so than its downstream counterpart. The bridge has what one may describe as "half-members," structural members added on at crucial points to reinforce the structure. On this particular bridge, the two innermost diagonal members have been reinforced. These sorts of members are what distinguish a Baltimore or Pennsylvania truss (in fact I at first thought this was a Baltimore truss, until I noticed the telltale "W"), but are much less common on Warren spans. Branching out from the center of each inner diagonal are two half-members: one connects to a vertical member, while the other connects to the top chord. There are also half-members that branch out from the middle of each front-post and connect to the bottom chord. All structural members are solid I-beams, with the exceptions of the front posts and the half-members. The bridge is undoubtedly a simpler, less interesting one than its downstream counterpart, but it is still very fortunate that it wasn't torn down when abandoned.		The upstream bridge is also an atypical Warren, perhaps even more so than its downstream counterpart. The bridge has what one may describe as "half-members," structural members added on at crucial points to reinforce the structure. On this particular bridge, the two innermost diagonal members have been reinforced. These sorts of members are what distinguish a Baltimore or Pennsylvania truss (in fact I at first thought this was a Baltimore truss, until I noticed the telltale "W"), but are much less common on Warren spans. Branching out from the center of each inner diagonal are two half-members: one connects to a vertical member, while the other connects to the top chord. There are also half-members that branch out from the middle of each front-post and connect to the bottom chord. All structural members are solid I-beams, with the exceptions of the front posts and the half-members. The bridge is undoubtedly a simpler, less interesting one than its downstream counterpart, but it is still very fortunate that it wasn't torn down when abandoned.
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	* [http://historicbridges.org/info/intro/ITHB.pdf An Introduction to Historic Bridges by Nathan Holth]		* [http://historicbridges.org/info/intro/ITHB.pdf An Introduction to Historic Bridges by Nathan Holth]
	* [http://maps.google.com/maps?ie=UTF8&ll=35.558851,-79.242711&spn=0.010963,0.022745&t=h&z=16 Google Maps Satellite View]		* [http://maps.google.com/maps?ie=UTF8&ll=35.558851,-79.242711&spn=0.010963,0.022745&t=h&z=16 Google Maps Satellite View]
			* [https://www.american-rails.com/original.html Norfolk Southern Railway (Original)]


	* '''[[Truss Bridges\|Return to Truss Bridges]]'''		* '''[[Truss Bridges\|Return to Truss Bridges]]'''
	* '''[[Main Page\|Return to the Main Page]]'''		* '''[[Main Page\|Return to the Main Page]]'''

Matthew at 14:56, 14 November 2020

2020-11-14T14:56:49Z

← Older revision		Revision as of 14:56, 14 November 2020
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	The single-span truss bridge continues to carry trains, while the two-span one in the background has been abandoned for quite some time. The trestle approaches leading up to the in-use bridge use modern steel i-beam columns as opposed to pine ones, indicating that it still carries a good amount of rail traffic. The disused bridge, in contrast, has been taken over in many spots by thick vines. Interestingly, the abandoned bridge has less rust on it than its companion.		The single-span truss bridge continues to carry trains, while the two-span one in the background has been abandoned for quite some time. The trestle approaches leading up to the in-use bridge use modern steel i-beam columns as opposed to pine ones, indicating that it still carries a good amount of rail traffic. The disused bridge, in contrast, has been taken over in many spots by thick vines. Interestingly, the abandoned bridge has less rust on it than its companion.

	The in-use bridge (hereafter referred to as the "downstream" bridge, despite being north of its abandoned counterpart) once carried the main line of the original Norfolk Southern Railway~~, a distinct railroad from the corporate entity of today~~ (like the nearby [[Norfolk Southern Cape Fear River Bridge]].) The abandoned downstream bridge carried the Atlantic and Yadkin Railway, which ran northwest from Sanford to Greensboro. Both railroads were eventually acquired by the Southern Railway. At some point in history, either the Southern or its successor, the current Norfolk Southern, chose to consolidate the lightly-used crossing into a single bridge and subsequently abandoned the A&Y bridge.		The in-use bridge (hereafter referred to as the "downstream" bridge, despite being north of its abandoned counterpart) once carried the main line of the original Norfolk Southern Railway (like the nearby [[Norfolk Southern Cape Fear River Bridge]]), a distinct railroad from the corporate entity of today. The abandoned downstream bridge carried the Atlantic and Yadkin Railway, which ran northwest from Sanford to Greensboro. Both railroads were eventually acquired by the Southern Railway. At some point in history, either the Southern or its successor, the current Norfolk Southern, chose to consolidate the lightly-used crossing into a single bridge and subsequently abandoned the A&Y bridge.

	Both of these structures utilize the Warren truss configuration, as indicated by the "W" pattern formed by their diagonal members. Each employs riveted gusset plate connections. These two features, along with the presence of I-beam members (as opposed to ones "stitched" together using small pieces of steel such as v-lacing), place the construction dates of both most likely within the first half of the twentieth century.		Both of these structures utilize the Warren truss configuration, as indicated by the "W" pattern formed by their diagonal members. Each employs riveted gusset plate connections. These two features, along with the presence of I-beam members (as opposed to ones "stitched" together using small pieces of steel such as v-lacing), place the construction dates of both most likely within the first half of the twentieth century.

Matthew at 14:55, 14 November 2020

2020-11-14T14:55:56Z

← Older revision		Revision as of 14:55, 14 November 2020
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	There is a pretty significant birch tree that has grown up in the soil that the river has piled up around the upstream bridge's pier. While it does make photographing the bridge's bearings more difficult, it undoubtedly performs a service in concealing the bridge's very bland concrete pier.		There is a pretty significant birch tree that has grown up in the soil that the river has piled up around the upstream bridge's pier. While it does make photographing the bridge's bearings more difficult, it undoubtedly performs a service in concealing the bridge's very bland concrete pier.

	=== Pictures of the ~~Downstream Bridge~~ ===		=== Pictures of the downstream NS bridge ===

	[[File:Dsc03700_1000.jpg\|200px]][[File:Dsc03708_1000.jpg\|200px]][[File:Dsc03709_1000.jpg\|200px]]		[[File:Dsc03700_1000.jpg\|200px]][[File:Dsc03708_1000.jpg\|200px]][[File:Dsc03709_1000.jpg\|200px]]
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	* Left: the western portal. Center: an top chord connection. Right: a bottom chord connection.		* Left: the western portal. Center: an top chord connection. Right: a bottom chord connection.

	=== Pictures of the ~~Upstream Bridge~~ ===		=== Pictures of the upstream A&Y bridge ===

	[[File:Dsc03680_1000.jpg\|200px]][[File:Dsc03667_1000.jpg\|200px]][[File:Dsc03678_1000.jpg\|200px]]		[[File:Dsc03680_1000.jpg\|200px]][[File:Dsc03667_1000.jpg\|200px]][[File:Dsc03678_1000.jpg\|200px]]

Matthew at 14:54, 14 November 2020

2020-11-14T14:54:38Z

← Older revision		Revision as of 14:54, 14 November 2020
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	[[File:Dsc03700_500.jpg]]		[[File:Dsc03700_500.jpg]]

	'''The in-use Norfolk Southern bridge in the foreground and the abandoned Atlantic and Yadkin in the background'''		'''The in-use Norfolk Southern bridge in the foreground and the abandoned Atlantic and Yadkin bridge in the background'''

	These two sturdily-built truss bridges are located about a mile or so upstream from the [[Deep River Camelback Truss Bridge]], between Lee and Chatham counties. Unlike the more famous bridge to the northeast, these two impressive structures are well hidden from the public and difficult to look at from either land or water. Dense tree cover makes getting complete pictures impossible during the spring and summer, while limited access from the road makes exploration a challenge. My photos of the bridges were taken from a kayak. A steep and slippery river bank prevented me from seeking out the bridge plaques and taking shots of the structures from dry land.		These two sturdily-built truss bridges are located about a mile or so upstream from the [[Deep River Camelback Truss Bridge]], between Lee and Chatham counties. Unlike the more famous bridge to the northeast, these two impressive structures are well hidden from the public and difficult to look at from either land or water. Dense tree cover makes getting complete pictures impossible during the spring and summer, while limited access from the road makes exploration a challenge. My photos of the bridges were taken from a kayak. A steep and slippery river bank prevented me from seeking out the bridge plaques and taking shots of the structures from dry land.

Matthew at 14:54, 14 November 2020

2020-11-14T14:54:06Z

← Older revision		Revision as of 14:54, 14 November 2020
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	'''Norfolk Southern Crossings of the Deep River near Cumnock, NC'''		'''Norfolk Southern Crossings of the Deep River near Cumnock, NC'''

	[[File:Dsc03700_500.jpg~~\|thumb~~]]		[[File:Dsc03700_500.jpg]]

			'''The in-use Norfolk Southern bridge in the foreground and the abandoned Atlantic and Yadkin in the background'''

	These two sturdily-built truss bridges are located about a mile or so upstream from the [[Deep River Camelback Truss Bridge]], between Lee and Chatham counties. Unlike the more famous bridge to the northeast, these two impressive structures are well hidden from the public and difficult to look at from either land or water. Dense tree cover makes getting complete pictures impossible during the spring and summer, while limited access from the road makes exploration a challenge. My photos of the bridges were taken from a kayak. A steep and slippery river bank prevented me from seeking out the bridge plaques and taking shots of the structures from dry land.		These two sturdily-built truss bridges are located about a mile or so upstream from the [[Deep River Camelback Truss Bridge]], between Lee and Chatham counties. Unlike the more famous bridge to the northeast, these two impressive structures are well hidden from the public and difficult to look at from either land or water. Dense tree cover makes getting complete pictures impossible during the spring and summer, while limited access from the road makes exploration a challenge. My photos of the bridges were taken from a kayak. A steep and slippery river bank prevented me from seeking out the bridge plaques and taking shots of the structures from dry land.

Matthew at 14:50, 14 November 2020

2020-11-14T14:50:02Z

← Older revision		Revision as of 14:50, 14 November 2020
Line 1:		Line 1:
	'''Norfolk Southern Crossings of the Deep River near Cumnock, NC'''		'''Norfolk Southern Crossings of the Deep River near Cumnock, NC'''

	[[File:Dsc03700_500.jpg]]		[[File:Dsc03700_500.jpg\|thumb]]

	These two sturdily-built truss bridges are located about a mile or so upstream from the [[Deep River Camelback Truss Bridge]], between Lee and Chatham counties. Unlike the more famous bridge to the northeast, these two impressive structures are well hidden from the public and difficult to look at from either land or water. Dense tree cover makes getting complete pictures impossible during the spring and summer, while limited access from the road makes exploration a challenge. My photos of the bridges were taken from a kayak. A steep and slippery river bank prevented me from seeking out the bridge plaques and taking shots of the structures from dry land.		These two sturdily-built truss bridges are located about a mile or so upstream from the [[Deep River Camelback Truss Bridge]], between Lee and Chatham counties. Unlike the more famous bridge to the northeast, these two impressive structures are well hidden from the public and difficult to look at from either land or water. Dense tree cover makes getting complete pictures impossible during the spring and summer, while limited access from the road makes exploration a challenge. My photos of the bridges were taken from a kayak. A steep and slippery river bank prevented me from seeking out the bridge plaques and taking shots of the structures from dry land.

Matthew at 14:47, 14 November 2020

2020-11-14T14:47:58Z

← Older revision		Revision as of 14:47, 14 November 2020
Line 3:		Line 3:
	[[File:Dsc03700_500.jpg]]		[[File:Dsc03700_500.jpg]]

	These two sturdily-built truss bridges are located about a mile or so upstream from the Deep River Camelback Truss Bridge, between Lee and Chatham counties. Unlike the more famous bridge to the northeast, these two impressive structures are well hidden from the public and difficult to look at from either land or water. Dense tree cover makes getting complete pictures impossible during the spring and summer, while limited access from the road makes exploration a challenge. My photos of the bridges were taken from a kayak. A steep and slippery river bank prevented me from seeking out the bridge plaques and taking shots of the structures from dry land.		These two sturdily-built truss bridges are located about a mile or so upstream from the [[Deep River Camelback Truss Bridge]], between Lee and Chatham counties. Unlike the more famous bridge to the northeast, these two impressive structures are well hidden from the public and difficult to look at from either land or water. Dense tree cover makes getting complete pictures impossible during the spring and summer, while limited access from the road makes exploration a challenge. My photos of the bridges were taken from a kayak. A steep and slippery river bank prevented me from seeking out the bridge plaques and taking shots of the structures from dry land.

	The single-span truss bridge continues to carry trains, while the two-span one in the background has been abandoned for quite some time. The trestle approaches leading up to the in-use bridge use modern steel i-beam columns as opposed to pine ones, indicating that it still carries a good amount of rail traffic. The disused bridge, in contrast, has been taken over in many spots by thick vines. Interestingly, the abandoned bridge has less rust on it than its companion.		The single-span truss bridge continues to carry trains, while the two-span one in the background has been abandoned for quite some time. The trestle approaches leading up to the in-use bridge use modern steel i-beam columns as opposed to pine ones, indicating that it still carries a good amount of rail traffic. The disused bridge, in contrast, has been taken over in many spots by thick vines. Interestingly, the abandoned bridge has less rust on it than its companion.

	~~Both of these structures utilize the Warren truss configuration,~~ as ~~indicated by~~ the "W" ~~pattern formed by their diagonal members. Each employs riveted gusset plate connections. These two features~~, ~~along with~~ the ~~presence~~ of ~~i-beam members~~ (~~as opposed~~ to ~~ones "stitched" together using small pieces of steel such as v-lacing)~~, ~~place~~ the ~~construction dates of both most likely within~~ the ~~first half of~~ the ~~twentieth century~~.		The in-use bridge (hereafter referred to as the "downstream" bridge, despite being north of its abandoned counterpart) once carried the main line of the original Norfolk Southern Railway, a distinct railroad from the corporate entity of today (like the nearby [[Norfolk Southern Cape Fear River Bridge]].) The abandoned downstream bridge carried the Atlantic and Yadkin Railway, which ran northwest from Sanford to Greensboro. Both railroads were eventually acquired by the Southern Railway. At some point in history, either the Southern or its successor, the current Norfolk Southern, chose to consolidate the lightly-used crossing into a single bridge and subsequently abandoned the A&Y bridge.

	~~The in~~-~~use bridge~~ (~~hereafter referred~~ to as the "downstream" bridge~~, despite being north of its abandoned counterpart)~~ is a Polygonal Warren truss, distinguished by the semi-arched shape to the top chord. Since the top chord has exactly three sections to it (or four angles), the bridge could also be considered a Camelback Warren, not to be confused with a true camelback such as the one to the northeast (which is based off the Pratt truss). There is a great deal of variety to the structural members of this bridge, demonstrating the amount of complex engineering its design required. The two diagonal members that point inward (the ones that run parallel to the front posts) are of a heavier construction than the others, with thicker beams that are stitched together using latticing. The innermost diagonals (the ones that form a "v" in the center of the span) are smaller and are stitched together using v-lacing, while the remaining four diagonals are simple i-beams. The vertical members that connect with diagonals on the top are solid i-beams, while those that connect on the bottom are stitched together. The bracing the connects the two trusses together at the top employs latticing ("x-ing"). The bridge is similar in design to a smaller one that crosses NC 87 in Burlington. One notable shared feature is the "W" pattern of the bracing at each bridge's portal. The Burlington structure was built by the Carolina Steel and Iron Company, which may or may not have erected this larger example.		Both of these structures utilize the Warren truss configuration, as indicated by the "W" pattern formed by their diagonal members. Each employs riveted gusset plate connections. These two features, along with the presence of I-beam members (as opposed to ones "stitched" together using small pieces of steel such as v-lacing), place the construction dates of both most likely within the first half of the twentieth century.

			The downstream bridge is a Polygonal Warren truss, distinguished by the semi-arched shape to the top chord. Since the top chord has exactly three sections to it (or four angles), the bridge could also be considered a Camelback Warren, not to be confused with a true camelback such as the one to the northeast (which is based off the Pratt truss). There is a great deal of variety to the structural members of this bridge, demonstrating the amount of complex engineering its design required. The two diagonal members that point inward (the ones that run parallel to the front posts) are of a heavier construction than the others, with thicker beams that are stitched together using latticing. The innermost diagonals (the ones that form a "v" in the center of the span) are smaller and are stitched together using v-lacing, while the remaining four diagonals are simple i-beams. The vertical members that connect with diagonals on the top are solid i-beams, while those that connect on the bottom are stitched together. The bracing the connects the two trusses together at the top employs latticing ("x-ing"). The bridge is similar in design to a smaller one that crosses NC 87 in Burlington. One notable shared feature is the "W" pattern of the bracing at each bridge's portal. The Burlington structure was built by the Carolina Steel and Iron Company, which may or may not have erected this larger example.

	The upstream bridge is also an atypical Warren, perhaps even more so than its downstream counterpart. The bridge has what one may describe as "half-members," structural members added on at crucial points to reinforce the structure. On this particular bridge, the two innermost diagonal members have been reinforced. These sorts of members are what distinguish a Baltimore or Pennsylvania truss (in fact I at first thought this was a Baltimore truss, until I noticed the telltale "W"), but are much less common on Warren spans. Branching out from the center of each inner diagonal are two half-members: one connects to a vertical member, while the other connects to the top chord. There are also half-members that branch out from the middle of each front-post and connect to the bottom chord. All structural members are solid I-beams, with the exceptions of the front posts and the half-members. The bridge is undoubtedly a simpler, less interesting one than its downstream counterpart, but it is still very fortunate that it wasn't torn down when abandoned.		The upstream bridge is also an atypical Warren, perhaps even more so than its downstream counterpart. The bridge has what one may describe as "half-members," structural members added on at crucial points to reinforce the structure. On this particular bridge, the two innermost diagonal members have been reinforced. These sorts of members are what distinguish a Baltimore or Pennsylvania truss (in fact I at first thought this was a Baltimore truss, until I noticed the telltale "W"), but are much less common on Warren spans. Branching out from the center of each inner diagonal are two half-members: one connects to a vertical member, while the other connects to the top chord. There are also half-members that branch out from the middle of each front-post and connect to the bottom chord. All structural members are solid I-beams, with the exceptions of the front posts and the half-members. The bridge is undoubtedly a simpler, less interesting one than its downstream counterpart, but it is still very fortunate that it wasn't torn down when abandoned.

Matthew at 03:21, 14 November 2020

2020-11-14T03:21:08Z

← Older revision		Revision as of 03:21, 14 November 2020
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	~~== Cumnock Railroad Bridges ==~~

	'''Norfolk Southern Crossings of the Deep River near Cumnock, NC'''		'''Norfolk Southern Crossings of the Deep River near Cumnock, NC'''

Matthew at 15:12, 25 February 2018

2018-02-25T15:12:06Z

← Older revision		Revision as of 15:12, 25 February 2018
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	[[File:Dsc03696_750.jpg\|112px]][[File:Dsc03692_500.jpg\|200px]][[File:Dsc03694_500.jpg\|200px]]		[[File:Dsc03696_750.jpg\|112px]][[File:Dsc03692_500.jpg\|200px]][[File:Dsc03694_500.jpg\|200px]]

			* Left: the western portal. Center: an top chord connection. Right: a bottom chord connection.

			=== Pictures of the Upstream Bridge ===

			[[File:Dsc03680_1000.jpg\|200px]][[File:Dsc03667_1000.jpg\|200px]][[File:Dsc03678_1000.jpg\|200px]]

			* Left: Partial view of the eastern span. Center: the western span and pier. Right: the eastern span and pier.

			[[File:Dsc03672_750.jpg\|200px]][[File:Dsc03676_500.jpg\|200px]][[File:Dsc03681_500.jpg\|200px]]

			* Left: an top chord/front post connection. Center: a bottom chord connection. Right: a bottom chord/front post connection.

			=== Sources ===

			* [http://historicbridges.org/info/intro/ITHB.pdf An Introduction to Historic Bridges by Nathan Holth]
			* [http://maps.google.com/maps?ie=UTF8&ll=35.558851,-79.242711&spn=0.010963,0.022745&t=h&z=16 Google Maps Satellite View]


			* '''[[Truss Bridges\|Return to Truss Bridges]]'''
			* '''[[Main Page\|Return to the Main Page]]'''

Matthew: Created page with "== Cumnock Railroad Bridges == '''Norfolk Southern Crossings of the Deep River near Cumnock, NC''' File:Dsc03700_500.jpg These two sturdily-built truss bridges are loca..."

2018-02-25T15:02:26Z

Created page with "== Cumnock Railroad Bridges == '''Norfolk Southern Crossings of the Deep River near Cumnock, NC''' File:Dsc03700_500.jpg These two sturdily-built truss bridges are loca..."

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== Cumnock Railroad Bridges ==

'''Norfolk Southern Crossings of the Deep River near Cumnock, NC'''

[[File:Dsc03700_500.jpg]]

These two sturdily-built truss bridges are located about a mile or so upstream from the Deep River Camelback Truss Bridge, between Lee and Chatham counties. Unlike the more famous bridge to the northeast, these two impressive structures are well hidden from the public and difficult to look at from either land or water. Dense tree cover makes getting complete pictures impossible during the spring and summer, while limited access from the road makes exploration a challenge. My photos of the bridges were taken from a kayak. A steep and slippery river bank prevented me from seeking out the bridge plaques and taking shots of the structures from dry land.

The single-span truss bridge continues to carry trains, while the two-span one in the background has been abandoned for quite some time. The trestle approaches leading up to the in-use bridge use modern steel i-beam columns as opposed to pine ones, indicating that it still carries a good amount of rail traffic. The disused bridge, in contrast, has been taken over in many spots by thick vines. Interestingly, the abandoned bridge has less rust on it than its companion.

Both of these structures utilize the Warren truss configuration, as indicated by the "W" pattern formed by their diagonal members. Each employs riveted gusset plate connections. These two features, along with the presence of i-beam members (as opposed to ones "stitched" together using small pieces of steel such as v-lacing), place the construction dates of both most likely within the first half of the twentieth century.

The in-use bridge (hereafter referred to as the "downstream" bridge, despite being north of its abandoned counterpart) is a Polygonal Warren truss, distinguished by the semi-arched shape to the top chord. Since the top chord has exactly three sections to it (or four angles), the bridge could also be considered a Camelback Warren, not to be confused with a true camelback such as the one to the northeast (which is based off the Pratt truss). There is a great deal of variety to the structural members of this bridge, demonstrating the amount of complex engineering its design required. The two diagonal members that point inward (the ones that run parallel to the front posts) are of a heavier construction than the others, with thicker beams that are stitched together using latticing. The innermost diagonals (the ones that form a "v" in the center of the span) are smaller and are stitched together using v-lacing, while the remaining four diagonals are simple i-beams. The vertical members that connect with diagonals on the top are solid i-beams, while those that connect on the bottom are stitched together. The bracing the connects the two trusses together at the top employs latticing ("x-ing"). The bridge is similar in design to a smaller one that crosses NC 87 in Burlington. One notable shared feature is the "W" pattern of the bracing at each bridge's portal. The Burlington structure was built by the Carolina Steel and Iron Company, which may or may not have erected this larger example.

The upstream bridge is also an atypical Warren, perhaps even more so than its downstream counterpart. The bridge has what one may describe as "half-members," structural members added on at crucial points to reinforce the structure. On this particular bridge, the two innermost diagonal members have been reinforced. These sorts of members are what distinguish a Baltimore or Pennsylvania truss (in fact I at first thought this was a Baltimore truss, until I noticed the telltale "W"), but are much less common on Warren spans. Branching out from the center of each inner diagonal are two half-members: one connects to a vertical member, while the other connects to the top chord. There are also half-members that branch out from the middle of each front-post and connect to the bottom chord. All structural members are solid I-beams, with the exceptions of the front posts and the half-members. The bridge is undoubtedly a simpler, less interesting one than its downstream counterpart, but it is still very fortunate that it wasn't torn down when abandoned.

There is a pretty significant birch tree that has grown up in the soil that the river has piled up around the upstream bridge's pier. While it does make photographing the bridge's bearings more difficult, it undoubtedly performs a service in concealing the bridge's very bland concrete pier.

=== Pictures of the Downstream Bridge ===

[[File:Dsc03700_1000.jpg|200px]][[File:Dsc03708_1000.jpg|200px]][[File:Dsc03709_1000.jpg|200px]]

* Various views of the bridge taken from the northern side.

[[File:Dsc03696_750.jpg|112px]][[File:Dsc03692_500.jpg|200px]][[File:Dsc03694_500.jpg|200px]]