Surf City Swing Bridge
NC 50 & 210 Crossing of the Intracoastal Waterway
**Update: This bridge has been demolished and replaced**
There are a few distinguishing facts to this bridge. It is the last remaining truss swing bridge on the Intracoastal Waterway in North Carolina. It is also the newest extant truss swing bridge and has the longest span. Between the 1920s, when the Corp of Engineers constructed the waterway, and the 1960s, when high-rise bridges started to appear, there was a significant number of these bridges spanning the waterway; I have seen pictures of them at Wrightsville Beach and Carolina Beach, for example. For these distinctions alone this bridge should warrant more respect. It also makes for a neat approach to the beach community, whether from the ocean or from the road.
By the time this bridge was built in 1955 most truss bridges were of the Warren configuration, in which the diagonal members together form a continuous "W" (or as with the case with this bridge, three "M's"). I may be wrong, but I'm pretty sure this is actually two Warren spans tied together in the center above the axis pier. The connections are mostly held together with rivets, though a few make use of crude-looking modern bolts (especially the connections that have been repaired.)
Despite the fact that it adds charm to the beach communities it serves, this bridge has received the typical amount of rudimentary maintenance, and in turn is rusting and crumbling under the traffic loads and salt water that is sprayed up onto it. Likely the state will deem it too far decayed to repair and will initiate the building of an unredeeming high-rise bridge to replace it. I suppose I'll be the only person who will miss it. It's too bad the state can't just build another bridge on the south end of the island. Currently if you're coming from I-40 you have to drive up US 17, then drive south again down the island. If a southern crossing were built, the traffic levels on the old bridge would drop significantly. But then again, the traffic levels probably do not warrant this, unlike at Myrtle Beach, for example, which has a few cases of old swing bridges remaining open in the shadows of high-rise bridges.
The concrete tee-beam approach spans to this bridge feature the decorative 1950s railings with arched openings and "staircase" blocks on the ends. For a more detailed description of this see my page on the US 117 Northeast Cape Fear River bridge. Another interesting thing on this bridge is the presence of cinder blocks on the lower chord of the swing span, on the western side of the waterway. I suppose these were added to balance out the span, to make up for all of the metal that has rusted away.
Status update: the replacement project for this bridge is under development, with the project tentatively set to begin in 2015. The page for the project can be found here. Of course, it appears that rehabilitation was never considered as an option. North Carolina so often take a disposable approach to its highway structures. It is of no surprise that the state is practically bankrupt.
Facts
- Year built: 1955
- Route Carried: NC 50 & 210
- Crosses: Intracoastal Waterway
- Location: Surf City, Pender County, NC
- Design: Warren truss swing span with tee-beam approaches
- Length of main span: 254.9 ft. Total length: 462.9 ft.
- Inside width: 24 ft., two lanes
- Average Daily Traffic: 11,000
- Sufficiency Rating: 6 out of 100
- National Bridge Inventory ID: 1410016
- Coordinates: 34°25'52.83"N, 77°32'59.34"W
Pictures
- Left: Oblique view of the main span. Center: In the process of opening. Right: Portal shot taken from the mainland.
- Left: A portal shot of the swing span, shot various bracing and members. Center: Inside the truss, showing the geometry of the intersection bracing and members. Right: A large connection that is located in the middle of the swing span, connecting the front posts of the two Warren trusses together.
- Left: A front post/upper chord connection, located on the mainland side of the bridge. Center: An upper chord connection. Right: A front post/lower chord connection, located next to the mainland abutment. Notice the concrete block on the lower chord.
- Left: An example of the decay of the underside. Center: The underside of the tee-beam approaches. Right: The axis pier of the swing span, along with part of the main mechanism. The beauty of this type of movable bridge is the simplicity of the mechanism. The main components are gears and a motor; there are no cables, counterweights, etc. It's probable that this design requires less energy as well. Some swing bridges, for example, could be rotated using a mere crank and a strong human arm. I can't imagine any human being able to crank open a bascule bridge!