DelDOT updates on Inlet Bridge process

By Sam Harvey
Staff Reporter

Delaware Department of Transportation (DelDOT) engineer Doug Robb reported a significant surge in the number of interested bidders for the significantly toned-down bridge portion of the Indian River Inlet Bridge project, at a May 9 construction advisory meeting.

According to Robb, the department was receiving quite a few calls — a welcome change from the last go-round, when DelDOT received just one single, solitary bid for construction of a bridge with a “tied arch” design.

That one lonely bidder dropped a few hints that the department’s cost estimates were way, way low, forcing DelDOT to abort the bidding process.

The tied arch, or “bowstring arch,” is a relatively common bridge design, but the formerly-envisioned bridge featured a unique, tulip-shaped concrete arch, with cable supports descending to the bridge deck.

The department’s primary goal for the project is to remove the pilings from the turbulent waters of Indian River Inlet. Therefore, any design DelDOT ultimately accepts will need to feature a 1,000-foot main span — but the length of the span may have increased contractors’ reluctance to tackle the unique arch.

Engineers are now anticipating a cable-stay design, similar to the Route 1 Bridge over the C&D Canal, where supporting cables radiate from two load-bearing towers, but a more traditional tied arch is still a possibility.

As Robb reiterated, the department had begun seeking bids from design-build (D-B) teams.

D-B teams assume responsibility for the whole package, which gives them the flexibility to start work in one section while they complete designs for areas scheduled further along the construction timeline. DelDOT is standing firm on its 2010 project completion date, though.

According to the Web site, www.irib.deldot.gov, the department will pick the winning team based on “price, schedule, aesthetic appeal, structure durability and public outreach.”

As of late last year, DelDOT estimated construction costs for the tied arch design in the $120 million range. Roadwork, demolition of the old bridge and park improvements were expected to bring total project costs to $230 million, with the federal government footing a little more than half of the bill.

The department has released no estimates, even ballpark ones, since terminating the bidding process for the unique tied arch. According to DelDOT officials, that is primarily because of the anticipated variability in the bidders’ designs.

According to Robb, the department had advertised for: (1) draft-quality requests for proposal (RFPs), and (2) requests for qualifications. He said the intent was to winnow it to a three- or four-team “short list” by the end of the summer, and then re-advertise for final-version RFPs.

Robb said he expected the winning team to initiate construction sometime in mid-2007. “Some teams might prefer a more advanced design before they jump into construction — more than likely, it will be a little later in the year (2007),” he pointed out.

DelDOT’s Dave Duke gave a progress report on the job site.

Crews have cleared off the old bridge, reopening two lanes in each direction, Duke pointed out. However, he warned that there was some additional work slated for the southeast corner (northbound Route 1, south side) where DelDOT plans to build a pedestrian walkway along the outside edge of the access road to the beaches on the south side.

Duke said they were expecting to use a pumping truck to get concrete to that location, which would likely require that crews once again close the outside lane, northbound.

The closure could last as long as a couple of weeks, he said, but he vowed to have both lanes open again by noon on Thursday, May 25 — before the Memorial Day weekend.

Elsewhere on Route 1, the acceleration/deceleration lanes, crossovers and turnarounds that will be in place for the duration of the project are all but complete.

Motorists headed south from Dewey Beach need to keep an eye out for the Inlet Road exit (for north-side day parking and the Indian River Marina) — the turnout is nearly a half-mile north of where it used to be.

There is now a left crossover for northbound motorists trying to access Inlet Road (again, roughly a half-mile north of the bridge), but it’s for left turns only. For U-turns, people still need to proceed to the crossing at Savage’s Ditch Road (about a mile north of the inlet).

It’s a lot to visualize, but DelDOT’s posted overhead maps of the construction zone — newly updated — on the project Web site (www.irib.deldot.gov). They’re right on the home page — just click the maps themselves for a closer look.

Work is proceeding ahead of schedule on the mechanically-stabilized-earth (MSE) walls that will eventually bear the causeways to the new bridge, Duke reported, and off-site, crews have completed a small bridge at Fresh Pond South.

Per federal regulations, DelDOT has to create an acre of wetlands to replace every acre of wetlands that will be disturbed by the pending bridge. The department considered about a dozen potential mitigation sites around the Indian River Bay, but the Fresh Pond sites were ultimately found to be the only suitable options.

At Fresh Pond South (near Fred Hudson Road), DelDOT will eventually fill/modify an existing pond — actually an old borrow pit, with steep banks — that department officials have labeled as potentially hazardous. Someone had fallen in and drowned in the pond, some years ago, they reported.

The borrow pit will assume a more marsh-like appearance as the mitigation progresses.