A bridge doesn’t stop being a structure. It just stops carrying cars.
Belmont Francis is following one bridge — the Lindsay C. Warren Bridge, which carries US 64 over the Alligator River in eastern North Carolina — from the day it is replaced to wherever its pieces end up. His question is the one that starts when the ribbon gets cut on the new bridge: when a bridge is done carrying cars, where does it go?
Every summer his family drove from Gastonia to the Outer Banks, and one of the last long crossings before the beach was the Alligator River on US 64 — low over the water, and a steel swing span in the middle that turns sideways to let boats through.
One summer, when he was about ten, it didn’t turn back. The family sat, then turned around, then drove the long way. NCDOT’s own release says that when the aging swing span has one of its “occasional mechanical failures,” it forces motorists “onto a 99-mile detour.” He has never forgotten the number, because he spent most of it asking his dad why a bridge would be built to move.
The bridge is being replaced now. A fixed-span bridge is going up just north of the old one, and when it opens, the old one comes down. That is where his question starts: 342 concrete approach spans and one steel swing span, and somebody has to decide where every piece goes.
The swing span is stuck open. Cars stop. His parents argue about the map. He counts the concrete spans he can see from the window and loses count somewhere past forty.
The gift: the question. A bridge is not a road. It is a machine, and machines have a last day.
Mornings in transportation, afternoons in environmental. He was supposed to declare a track. He kept walking the path between the two instead, because every time he tried to pick one, the bridge turned out to belong to both.
The gift: the seam. Transportation decides when a bridge stops carrying cars. Environmental decides what happens after. It is the same bridge at two different times.
The news arrives on his phone between classes: the state’s Division of Marine Fisheries is proposing a new artificial reef in Albemarle Sound, and “Materials for this planned project are debris from the Alligator River Bridge.”
The gift: the thesis. The bridge he sat behind as a kid may end up on the bottom of the sound, as fish habitat. Now somebody has to work out whether it stays where they put it.
The first time he looked the bridge up, he found three numbers that didn’t agree, all from people who should know. He has not trusted a number about this bridge since unless he could see where it came from.
It is the habit that put him in Abraham Alakasarian’s office. Alakasarian has made a career of one number — the yellow interval at a traffic light — and of refusing to let anyone fudge it. Belmont brought him a bridge full of numbers that had been rounded, copied and re-printed. Alakasarian took him on the same afternoon.
May 2022. NCDOT’s federal grant application: it is “evaluating potential use of materials from the demolition” as artificial reefs in Albemarle Sound.
Dec 2025. A trade-press feature: the old bridge’s components “will be processed into recyclable products or used as an inland artificial reef.”
Jan 2026. NCDOT’s resident engineer, as reported: steel recycled, concrete “collected and crushed for use on other NCDOT or local road projects.”
Nov 2026. DMF proposes reef site AR-195, built from “debris from the Alligator River Bridge.” Nobody has said yet which piece goes where.
Transportation and environmental engineering are the same bridge at two different times. One side decides the day it stops carrying cars. The other side inherits 342 spans the morning after. He refuses to pick a building because the bridge never did.
The working notebook.
Most of his entries are not experiments yet. They are numbers about one bridge, written down next to where each one came from — and the places where two of them disagree. He logs the disagreements instead of picking a winner. Notes update as the project moves.
DMF’s public informational meeting on the new reef is Thursday, December 3, 2026, at 6 p.m., Room 110, College of the Albemarle, Manteo. It is a long drive. I’m going.
Questions I’m bringing: How much of the bridge goes in the water, and which pieces? What is the bottom like at the site? How tall can a span sit and still clear the navigation rule? Who decided between crushing the concrete and reefing it?
The Division of Marine Fisheries is proposing a new estuarine artificial reef in Albemarle Sound. The site is about 125 acres, about 3.5 miles northeast of the mouth of the Alligator River, and the material is debris from my bridge.
What it does not say yet: how much. The Albemarle Observer put it plainly — state officials “have not yet announced how much bridge material would be used or when construction of the reef might begin.”
Precedent: when the old Bonner Bridge at Oregon Inlet came down, 80,000 tons of concrete went out in 68 barge loads to eight reefs. Nobody has said yet whether this one is that kind of number.
Lined up every document I have that says what happens to the old bridge, in date order:
Dec 2025 · trade press: recyclable products or an inland artificial reef
Jan 2026 · resident engineer: steel recycled, concrete crushed for road projects
Nov 2026 · DMF: reef AR-195, from the bridge’s debris
The reef idea is in the record from 2022. What none of them says is which pieces go to the reef and which get crushed. That split is my Stage 2.
NCDOT describes 342 approach spans, “each approximately 50 feet.” That is 17,100 feet. The National Bridge Inventory has the whole structure at 15,059.1 feet.
Take out the 261-ft swing span and divide: (15,059 − 261) ÷ 342 ≈ 43 feet average. “Approximately 50” is doing seven feet of work per span, two thousand feet over the bridge.
Not an error, exactly. Nobody would notice until they had to weigh every span.
The 2022 grant application says the new bridge’s substructure will use carbon fiber bars instead of steel rebar, because corrosion is what “significantly affected the life” of the old one.
The as-built reporting names different rebar. January: “Instead of steel inside the concrete, they’re using glass fiber reinforced polymer.” October, from the site: “carbon fiber strand in the piles and GFRP rebar.”
Both are non-steel and both answer the corrosion problem. But the design document and the bridge in the river name different rebar, and I would rather write that down than smooth it over.
January 2025, NCDOT: under the contract, the new bridge “will open to traffic in the fall of 2029, with demolition of the current bridge to begin in the spring of 2030.”
January 2026, NCDOT’s resident engineer, as reported: it “could open a year earlier.” October 2026, a Hampton Roads TV station, in its own narration: “In fall 2028.”
For my degree plan this is not trivia. BS in spring 2027. If an MS takes two years, fall 2027 to spring 2029. A fall 2028 opening puts the start of demolition in my MS. A fall 2029 opening puts it in my first PhD year. Either way the reef comes after, and its date has not been announced.
NCDOT says the bridge was completed in 1960, and the National Bridge Inventory says built 1960. NCDOT’s own 2018 press release calls it “59-year-old”. A January 2026 newspaper story says “The old bridge opened in 1962.”
Those don’t have to contradict each other. A bridge can be finished one year and open to traffic later. Logged as a question, not an error: what happened between 1960 and 1962?
Assumption failed. Asphalt is one of the materials reef rules keep out of the water, so I flagged the deck as a problem. Then I found NCDOT’s November 2018 release on a $16.7 million, 17-month renovation that gave the bridge a new epoxy deck overlay.
So the top layer is epoxy, not asphalt. What’s under the epoxy, I don’t know. Assumption narrowed, not killed.
An estimate, not a measurement. Every input is a guess until I get the as-built plans:
five girders, ~2.6 ft² section each ≈ 559 ft³
rails, both sides, guessed ≈ 200 ft³
total ≈ 1,550 ft³ → ~116 tons dry at 150 pcf
submerged in fresh water (150 − 62.4 pcf) → ~68 tons
lying deck-down on 1,355 ft² → ~100 psf (0.7 psi)
on the girder flanges, ~1.5 ft wide each, ~330 ft² → ~410 psf (2.9 psi)
For scale, a 180-lb person standing on about half a square foot is roughly 360 psf. Deck-down, a span presses on the bottom less than you do. On its girders, a little more. Fresh water, not seawater, because the sound is mostly fresh. And this is static only: a span dropped from a barge is a different problem I have not modeled.
Who he checks his work against.
A transportation engineer for the day the bridge stops carrying cars, an environmental engineer for the morning after, and a materials scientist for the question of whether a pile of concrete stays where you put it. The standing question is taped over his desk.
Told him I was treating the bottom like a pavement problem. He stopped me. “In a pavement, the binder does the work. On the bottom of the sound there’s no binder. It’s just the pile and whatever’s under it.”
Then he turned his Bennu lecture around on me: “That spacecraft nearly sank into a pile nobody understood until they touched it. Do you know what your surface is?”
I didn’t. Went and looked: NOAA surveyed this part of the sound in 2023, and the published coordinate for the site falls inside that survey’s outline, about 0.2 km from its edge. But the nearer of that survey’s two bottom samples is about 20.6 km from AR-195 (soft silt, fine sand, shell hash). The other is about 36 km away (mud). That survey took none at the site.
Brought him the detour. NCDOT’s 2022 grant application says “over 90 miles.” NCDOT’s 2025 contract release says “a 99-mile detour.” Same agency, same bridge.
He drew it on a napkin before I finished the sentence. His line: “Neither one is wrong yet. A detour is a route, not a number. Find the road each of them drove, then you’ll know which number belongs on a sign.”
Then he gave me three questions for Manteo, and made me write them in ink.
She asked me her question — the one Seika and Percy both warned me about: “If this works, who stops using a landfill? Name them.”
I said that for this bridge, the plan on record in January was to crush the concrete for road projects. Not a landfill.
Her line: “Then your reef is not competing with a landfill. It’s competing with a road. Find out who loses the aggregate if the spans go in the water, and put a number next to their name.”
Ran into Percy Anderson, who has “Where does the bag go?” taped over his bench. Mine says “Where does the bridge go?” Seika Chiyon’s is the polymer left over after diaper recycling. Three students, three materials, one question: what is the second life of the stuff we’re done with?
The difference is scale. Percy’s material fits in a bag. Seika’s fits in a lab. Mine needs a barge.
Abraham Alakasarian, Dr. Etadol Obodat and Dan Coner are fictional faculty members, and Belmont Francis is a fictional student. The bridge, the reef proposal and the records on this page are real and cited — see the Research Map. The work on this page belongs to the N.C. Department of Transportation, the N.C. Division of Marine Fisheries, NOAA’s Office of Coast Survey (survey H13762), the Albemarle-Pamlico Estuarine Study and the reporters named in the sources. None of them has anything to do with this campus, and nothing on this page is attributed to them that is not in their documents.
From bridge to reef.
Five stages between the last car across the old bridge and fish living on its pieces. The first is being built right now. The fourth is the thesis: he has found no bottom sample where the spans would go.
A fixed-span bridge is going up just north of the old one: a $450 million contract with Skanska. The first piles went in in February 2025, and NCDOT says “One year later, all 710 piles were in place.”
When it opens, the swing span stops turning. NCDOT counted between 3,000 and 4,000 openings a year since 2016, and a mechanical failure means the 99-mile detour. He does not design this stage. He starts the day it finishes.
342 concrete approach spans — a cast-in-place slab on precast, prestressed girders — and one 261-ft steel swing span. The records point two ways: concrete crushed for road projects and steel recycled, or debris to reef AR-195. None of them says which pieces go where. His senior project starts here: a span-by-span inventory of what the bridge is made of and how much it weighs.
A list of questions, not answers yet:
— what is under the 2018 epoxy deck overlay?
— asbestos: demolition “must comply with EPA’s Asbestos Demolition and Renovation Rule” (TxDOT guidance)
— rebar ends, and grease and oil in the swing-span machinery
NOAA’s National Artificial Reef Plan says bottom type and depth “should be obtained before a site is actually permitted for development of artificial reef construction,” and that “In most cases, soft sediments such as clays, silts, and loosely packed sands should be avoided. Over time, reef materials may sink into these sediments or become partially covered.”
It has happened before: off Mississippi, three barge loads of concrete rubble “could not be detected during a side-scan sonar survey” on a silty-clay site, and the guidelines assume “this material also subsided.” And a 1989 study of the sound found soft, gel-like fluid muds “present … in Albemarle Sound.”
What he has for AR-195 itself: no bottom sample. The nearer of the two samples in NOAA’s 2023 survey is about 20.6 km away. His own estimate says a span’s weight on the bottom is small, so this is a soil question — and he has found no measurement of the soil at the site.
Watch it after it goes in: how far each span settles, how much height it keeps above the bottom, and what lives on it. Height has a ceiling: “All artificial reefs are required to maintain minimum navigation clearance on an individual basis according to each permit.”
And a question most reef stories skip: the 1989 study says “Albemarle Sound, except near its juncture with Croatan Sound, is nearly always fresh.” Which fish does a reef hold in water that fresh? And does a reef make more fish, or gather the ones already there? That one is next on his reading list.
The old and new bridge. NCDOT, Lindsay C. Warren Bridge Replacement project page (accessed Nov 2026). · NCDOT, USDOT MPDG grant application narrative (2022). · NCDOT press release, Jan 8, 2025, “Work to Begin Soon on Alligator River Bridge Replacement.” · NCDOT press release, Nov 2, 2018, on the completed renovation. · National Bridge Inventory record, structure 000000001770007, via BridgeLookup.
Reporting. Richard Stradling, “New Alligator River bridge taking shape in Eastern NC faster than expected,” Jan 13, 2026 (via Yahoo News). · WTKR News 3, “Alligator River Bridge Project more than 50% complete, remains on schedule for fall 2028,” Oct 2, 2026. · Cindy Riley, “Skanska Builds $450M Alligator River Bridge,” Construction Equipment Guide, Dec 31, 2025. · Albemarle Observer, “Old Alligator River Bridge could find new life as artificial reef in Albemarle Sound,” Nov 5, 2026.
The reef. NC DEQ press release, Nov 4, 2026, “Public informational meeting scheduled for new artificial reef site in Albemarle Sound.” · Coastal Review, “State adds tons of material to artificial reefs,” Jun 14, 2022 (Bonner Bridge). · NOAA, National Artificial Reef Plan (2007). · GSMFC, Guidelines for Marine Artificial Reef Materials, 3rd ed., No. 296 (March 2020). · NC DMF reef-program document (2019). · UF/IFAS Bay County, allowable reef materials. · TxDOT, bridge demolition and renovation guidance. · WAVY, Virginia reef asphalt order.
The bottom. NOAA Office of Coast Survey, hydrographic survey H13762 (2023): descriptive report, survey outline and bottom samples (NCEI). · Albemarle-Pamlico Estuarine Study, sediment scoping study (1989). Distances from AR-195 to the samples are his own calculation from the published coordinates.
Fiction, and said so: the summer detour, the three scenes and every line spoken by faculty are story. Coner’s Bennu line is story too, but the event is real: NASA’s Bennu facts page says the spacecraft “would have sunk into the surface of Bennu had it not fired its thrusters to back away…” (NASA, “Bennu Facts,” updated Apr 23, 2025). Not held here: any bottom sample at the reef site. As of Nov 6, 2026. This project is live, the schedule has already moved once, and these notes will change as he goes.