Shaping up bridge for second 100 years; CSXT's Schuylkill River bridge in Philadelphia carries heavy volumes of traffic, but needed rehab to do the job into a second century

Railway Track and Structures, Oct, 2004 by Tom Judge

In 1910, the Baltimore & Ohio constructed a two-track swing bridge spanning the Schuylkill River in Philadelphia. Nearly a century later, that same bridge, now on CSX Transportation's main line, carries high traffic volumes, with priority traffic ranging from mail to orange juice. How do you rehabilitate a 94-year-old bridge under heavy traffic? Very carefully, with lots of advance planning, carefully-structured logistics and precise scheduling.

In 1977, the railroad conducted an engineering study of the bridge's miter rails and associated machinery. There was no doubt that the work would be needed, but other priorities came ahead of this one.

The existing miter rails were sliding rail locks installed on a timber deck.

The slide rails and deck had deteriorated to the point that operations were affected. The signal system was also a problem.

Miter rails, head blocks and more

CSXT decided to upgrade to a Ridex[R] miter rail system with steel ties.

CMI-Promex was given a contract to design, build and install a Ridex miter rail system for the bridge.

Steel head blocks were replaced and the existing wood ties were replaced with steel ties.

The Ridex rail plates were assembled to the steel ties into panels to aid in installation.

The existing mechanical system for rail actuating was in poor condition.

It was retired and replaced with hydraulic rail lifters.

The existing wedge cylinders (center and end) were in poor condition.

They were replaced.

The signal system and bridge control were upgraded to state-of-the-art proximity sensors.

Since this is a very important bridge for CSXT, track time allocated for installation was critical. Detailed planning on manpower, material and equipment was required to fit the work into the time period. Pre-fabrication of track panels saved considerable time.

The ends of the bridge are angled, so the design and fabrication of the steel ties was complex.

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The work was accomplished in two four-day outages. One track was replaced in each of the outages.

Many trains were diverted. However, some traffic was allowed to pass on the bridge as work progressed.

"This is an extremely-important bridge, an extremely-important link," said Wayne Ligato, president of CMI-Promex. "The orange juice train, the mail train, the UPS train, the garbage train and the circus train all go over this bridge. Many important cargoes, such as the mail, orange juice and so on, are traveling over this bridge literally every day in large volumes. Interruption of service in that facility would cause a great deal of consternation."

This bridge was under serious consideration for repair for many years. And there were some FRA violations tossed into the mix.

The rehab project was resurrected late in 2003, after which it moved very fast.

"I think we had our meetings with CSXT where we actually put this thing to bed in early 2004, January or so," Ligato said. "It was scheduled for May installation. The project was turned loose in January and we were asked to pull this whole thing together and to be ready to install the product for a May outage. We had less than four months to pull this whole thing together."

The construction schedule was determined by a combination of organizations. G. W. Peoples was the installer under CMI-Promex supervision.

"The genesis of the schedule came from a combination of circumstances, that is, what both the rail traffic and Coast Guard would allow, then the practical issue of what the laws of physics would allow with regards to men and machines and time. We were able to deal with this project on a corner-by-corner basis rather than track-by-track basis. We would go to a corner over a 36-hour period, tear it out and replace it and bring the bridge back into service for a period of time. Then we'd go to the next corner, tear it out and replace it. The bridge always had to be operational at the end of a 36-hour period. It would have been nice to just tear everything apart and do the work, but we didn't have that luxury. On the two-track bridge, they can continue to run trains on another track, so interruptions were frequent."

Another issue is that once the bridge is torn up, it can't be opened for river traffic. From a river traffic standpoint, there's a very critical time window.

"If you start stacking boats in the river, fines can be big and ugly," Ligato noted.

He continued: "The work involved changing hydraulics and bridge mechanicals, changing-out bridge decking from wood ties to steel ties and making several little pleasant discoveries along the way, as you can imagine with a bridge that old. Modifications and changes occurred on the bridge that never showed up in the drawings and that can't be anticipated or seen until you start taking the bridge decking apart. So we had a lot of what I call two-o'clock-in-the-morning surprises. Fortunately for us, because we had the machine shop, we could rectify and modify things in order to stay on schedule."

The bridge was not exactly parallel or perpendicular after a 94-year period. This caused a lot of problems with regards to angles and cuts and movements.