A failed fiber backbone across the harbor, replaced in one scheduled outage.
The air-blown fiber along the eastern span of the Vincent Thomas Bridge had failed between two bents. We took it out, rebuilt the pathway, blew in new cable, and spliced and tested every strand before the window closed.
Singlemode cables blown in, 24 strands each, 144 strands total
Section of the eastern span where the failed fiber and tube were removed
New splice and distribution centers on the structure and in the port vaults
All removal, duct, blowing, splicing, and testing inside a single scheduled window
You don't get to close a harbor bridge twice.
The Port's fiber backbone crosses the Main Channel on the Vincent Thomas Bridge in Sumitomo air-blown tube cable, strapped to the structure bent by bent. Somewhere between Bent 12 and Bent 20 on the eastern span, the fiber had failed. On a bridge, the fix isn't a splice at the break: the failed tube and fiber come out of the structure, the pathway is rebuilt, and new cable goes in end to end.
All of that has to happen inside a scheduled service outage, on a structure with traffic above and water below, with the Port's other systems still depending on the strands that weren't broken. The job is less about the fiber than about getting the pathway, the splicing, and the testing done in the window you're given, because there isn't a second one.
Rebuild the pathway, then the fiber.
Sumitomo's field engineer worked alongside our crew for the duct installation, so the FutureFLEX pathway went in the way the manufacturer specifies it, including expansion trays where the structure moves.
Removal
The failed fiber and tube were pulled out of the bridge structure from Bent 12 to Bent 20 during the outage, clearing the pathway for new duct.
Pathway
New Sumitomo FutureFLEX duct along the eastern span, with expansion trays at the points the engineer called for, and new splice and distribution centers built at three bents.
Vaults
Splice and distribution centers installed in the Port vaults at Ferry Street and the Caltrans lot, tying the bridge run back into the Port's backbone on both sides of the channel.
Fiber
Six 24-strand singlemode cables blown into the new duct, 144 strands across the span.
Splicing and testing
Every strand fusion-spliced on a core-alignment splicer, then tested strand by strand before the backbone was returned to service.
The work under the deck.
What was in the contract.
- Removal of failed air-blown fiber and tube, Bent 12 to Bent 20, eastern span
- Sumitomo FutureFLEX duct installation with expansion trays, with the manufacturer's field engineer on site
- Splice and distribution centers at three bents
- Splice and distribution centers in the Port vaults at Ferry Street and the Caltrans lot
- Six 24-strand singlemode cables blown in
- Core-alignment fusion splicing of all strands
- Testing of every strand prior to return to service
- All work performed inside a single scheduled outage
Back in service inside the window.
The eastern-span backbone was returned to service with 144 spliced, tested strands in new duct, on the Port's schedule.
In service since 2022 with no fiber-related outages.
Other jobs where the pathway was the project.
Harbor College data center relocation
21,000 feet of singlemode to fifteen buildings, 200-pair OSP copper, and a new room built to LACCD spec.
County of OrangeCountywide structured cabling contract
Engineering, installation, and repair across County facilities since 2021, under prevailing wage.
Fiber across something hard to reach?
Bridges, campuses, tunnels, and pathways that only open once. Send us the drawings and an engineer will tell you how we'd do it and what it costs.