TDOT Chief Engineer Updates Public on Plans for Sligo Bridge

A decision on whether to repair or replace Sligo Bridge may still be months or years away, depending upon the availability of funds.
Paul Degges, Chief Engineer for the Tennessee Department of Transportation, addressed a room full of concerned citizens Monday night at the courthouse, as to the plans for the bridge.
State Senator Mae Beavers and State Representative Terri Lynn Weaver hosted the meeting.
Degges says the state has inspected the bridge and found it to be safe. “We’ve got a truss bridge over the river. It’s about 24 feet wide. We inspect all of our bridges every two years to try to make sure that the bridge is in good shape and it’s safe to keep traffic on it. We came back a few years ago and put a second reinforced steel concrete deck over the old deck on this bridge. So it actually has two bridge decks on it. The older deck down underneath is having some deterioration problems. You may have noticed we have some netting under there. It’s not a structural issue with the bridge. The netting is to keep stuff from falling down and hitting somebody. From a structural condition, the bridge is structurally in pretty good shape for a bridge this age. So it is safe to drive on. We don’t have any issues with safety.”
If a new bridge is built at Sligo, Degges says it would be designed differently than the existing structure. ” The steel in a truss bridge like this is a different technology than we use today. The steel we use in bridges today is a much higher strength steel. It’s much more resistant to rust and weather. We’re proposing a new bridge over the river at 1,545 feet long. One of the things we’re also looking at based on current traffic is that we want to make sure we have two twelve foot lanes and full shoulder widths on the bridge. We also want to be prepared in the future to be able to come in and widen the bridge so we would put a wider sub-structure in the river and then in the future if we needed to widen the bridge out we could do that. This bridge is a unique structure in that the water is 137 feet deep from normal pool down to the bedrock below the mud in the river. That is probably the deepest water work we have ever done in the state of Tennessee.”
While no decision has yet been made to replace the bridge, Degges says the state can now proceed with right of way acquisition. “We have gotten through the preliminary design phase of the process that gives us a set of plans to go buy right of way with. We’re in the right of way acquisition phase right now to buy the right of way to build the new bridge. We’ve cleared the environmental hurdles and we’re buying the right of way right now”.
Degges says it would cost about $32 million to replace Sligo bridge at today’s estimates, while a rehab would be about $12 million and extend the life of the bridge by 10 to 15 years. ” A replacement job here is 32 million dollars. That is roughly half of the amount of federal funds that we (state) get in a year. We get about $60 million a year in federal funds for bridge replacements and by law I have to put about 15% of that money on county highways. So it’s ($32 million) a big lick with 20,000 bridges in the state of which about 8.000 are on the state highway system.”
“We would probably get about 50 years out of a new bridge and have the ability to widen or rehab it with relatively minor impacts to the traveling public. Truss bridges are a much different issue because since the truss is overhead, you’re limited on the width, so to be able to come in there and do any (rehab) work on this bridge would be very difficult without having to close the bridge for at least some time. What we’ve looked at is for about $12 million and maybe a little cheaper, we could do a rehab on the truss and probably buy ourselves ten to fifteen years. To do the rehab work, we would probably have to have at least two to three different time frames of a total closure within the order of a month.”
“From a time frame standpoint, between two and four years from now this bridge is going to be in a condition to where we’re going to have to replace the bridge or do a rehab on it.”
According to Degges, if funding could be secured for a bridge replacement, the project could be under contract within fifteen months. “Based on our current funding, it was unclear how we could come up with the $32 million plus or minus to replace the bridge. However, a stimulus package is being talked about in Congress right now. That could forseeably put a lot of money in Tennessee for transportation projects. If that’s the case, this bridge may or may not qualify for the stimulus money. If it does not, other money could be freed up which could be applied to the bridge.”
“A second opportunity is a proposal offered by TDOT Commissioner Gerald Nicely with the approval of Governor Bredesen called a bridge bonding program. In Tennessee, we are a pay as you go state. We have zero debt on your transportation system. We don’t borrow money to build a road. We wait until we have the money and then we let the contracts. So with a pay as you go system, we’re not paying interest on debt. We’re taking all of the money you pay in fuel taxes and title and registration fees to build roads. In general, the General Assembly has been very proactive in pushing TDOT to live within it’s means so that’s what we’re trying to do. But bonding is a tool and under that program, we could do about seven to nine years worth of work in about three years. This bridge would fit the criteria of that program.”
“If we were able to find the funding for this project, I could see us under contract in maybe fifteen months or less if we were going to go with the new bridge. If the money doesn’t materialize somewhere, I would guess somewhere between two and four years from now we would be looking at a rehabilitation project on the existing bridge.”