Thursday, August 04, 2011

NS bridge replacement in Northwest Pennsylvania

Received a couple of emails from a regular correspondent from Greenville, PA, which is in Northwest PA, about 20-25 miles north of Sharon, PA.  It seems Norfolk Southern is going to replace a railroad bridge in the area, and they had offered it for sale to anyone who would dismantle it, move it, and reassemble and preserve it.  Apparently nobody stepped forward.  He also discusses how a railroad bridge is replaced with minor interruptions to service by a horizontal jacking process.  Interesting stuff.  Here are the emails.

Subject: ERIE RR Shenango River Lattice Truss Bridge Replacement Project Update at Shenango, PA
Date: Tue, 26 Jul 2011

Noted over the weekend, as I drove by the CN/B&LE Shenango Yard along PA Route 18 south of Greenville, that the cab and boom of a large crawler crane is now at the adjacent bridge replacement project site, with the boom partially assembled. The erection of the new Norfolk Southern Railway span behind the B&LE yard must be about to begin. I hate to see the historic structure have a date with a steel furnace, but I am very pleased to see the NS making millions of dollars of capital investment in the Meadville Line.

The method of bridge replacement at Shenango is to be the same as that which NS employed in 2001 when replacing another similar, but shorter former Erie RR, single-track through-truss bridge over Little Yankee Run on the NS Meadville Line between Sharon, PA and Hubbard, OH. There, to minimize the out-of-service time of the main track, NS structures engineers used a time-honored process that has been used to replace many railroad bridges: jacked spans. Once the replacement bridge is constructed on temporary abutments, parallel to the truss bridge, the existing truss spans will then be slid sideways out of line from the main track and away from the new bridge, again, on temporary abutments. The new spans will be moved into place (the vacant former location of the original bridge), connected with the Meadville Line trackage and placed in service. The 100+ year old, quadrangular Warren through-trusses will be razed and cut up for scrap, and the temporary abutments removed. The attached has a link to contractor Seidler Engineering's web page and a dozen project photos and narrative documenting the November 9, 2001 cut-over between old and new bridges near Hubbard in under nine hours.

Bennett Levin's pair of E8 locomotives that will cross the truss bridge at Shenango on Sunday, August 7 with a westbound private passenger excursion will thus become the last pair of E8As to ever pass through the existing truss structure. And, the patrons aboard that excursion train will become the last passengers to ever cross the Shenango River via that old iron, and will have an exceptionally rare notation to make in their rare-mileage rail travel chronicles!

Subject: Bridge Replacement: Jacked Spans - Little Yankee Run and Allegheny River
Date: Mon, 8 Nov 2010

Attached is a link to Seidler Engineering's web page narrative and a dozen project photos documenting the November 9, 2001 replacement by Norfolk Southern Railway of the former Erie Railroad single-track, 147' 7 through-truss bridge over Little Yankee Run east of Hubbard, Ohio. For a full century, all Erie RR, Erie Lackawanna, Conrail and Norfolk Southern freight trains moving on this busy line via Youngstown, OH and Sharon, PA, and every Erie/EL through-line passenger train that operated between New York City and Chicago, had passed through the portals of this truss near the Penn/Ohio state line. To minimize the out-of-service time of the NS Meadville Line main track, the actual transition between using the old and new structures took less than 9 hours, using a time-honored process that has been used to replace many railroad spans.

The new, through-girder replacement was erected upon the upstream side of a temporary structure built beneath and extending beyond both sides of the existing bridge. When the new bridge was ready, the track of the retired through-truss was disconnected and the old bridge was jacked sideways on the temporary structure beneath it, out of its long-time alignment, to a clear point downstream from the railroad centerline. The new spans were then jacked over, also moving downstream along the temporary structure, and permanently secured in place to new abutments on the original railroad alignment.

The adjoining land-side tracks were then connected with those built with prefabricated panels on the new bridge, and rail traffic resumed. The temporary structures and retired truss were then removed without creating conflict with passing trains. The contractor's 're-use of scrap material' from earlier bridge projects to assist on this one, as described in the narrative, even involved girders from highway bridge replacement projects, judging by photos showing the non-railroad paint, thereon:

The above two bridges are relatively small structures, but much, much larger and higher rail spans have been similarly replaced using this build-jack-and-raze method. One with which anyone traveling the Pennsylvania Turnpike over the Allegheny River at Oakmont, PA in daylight would be familiar is the former Bessemer and Lake Erie Railroad's own Allegheny River crossing, just upstream from the Turnpike bridge.

The B&LE completed a new double-track bridge, soaring 160' above the river, in 1918. It first was erected right alongside the existing single-tracked structure. In preparation to do so, the substructure contractor extended the width of the five main piers beneath the river spans (though a new south abutment was required). The river spans, all of continuous truss design, range from the shortest, at 272'-0", through two of nearly 350', to the longest, at 520'-1" over the river's main channel. All were jacked downstream into place on the piers, once the retired structure was moved into the clear. "This structure not only introduced new silicon steel to American bridge construction, but also helped revive continuous truss design."

"American Bridge Company fabricated the new superstructure and erected it atop the completed piers. The company used cantilever erection, working outward from the piers to meet at mid-span over the river channel. Old and new structures shared the piers until the new structure was completed and the old one removed. Crews then shifted the new structure sideways to occupy the center Line of the piers."

Bessemer and Lake Erie Railroad, Allegheny River Bridge: HAER No. PA-508

Subject: PennDOT Marketed Norfolk Southern's former ERIE RR Shenango River Lattice Truss Shenango River Bridge at Shenango, PA in March, 2010 (+ DEP Permit)
Date: Thursday, July 28, 2011

PennDOT Marketed Norfolk Southern's 1895 former ERIE RR Shenango River Lattice Truss Shenango River Bridge on the Meadville Line at Mile Post 130.35 at Shenango, Mercer County, PA (near Greenville) in March, 2010.

The Pennsylvania Department of Transportation, Cultural Resources Management Program: Bridge Marketing, put up this web page (link, below) in March, 2010 on behalf of Norfolk Southern Railway to seek a party to acquire the historic, two-span double-intersection Warren through-truss "(also known as a Warren Quadrangular Truss), which has a distinctive crosshatched appearance".

Here is the "Water Obstruction and Encroachment" permit issued by the Department of Environmental Protection for this project, as published on Saturday, May 22, 2010 in The Pennsylvania Bulletin:

E43-347, Norfolk Southern Corporation, 1200 Peachtree Street NE, Box 142, Atlanta, GA 30309. Bridge MI-130.35, in Hempfield and West Salem Townships, Mercer County, ACOE Pittsburgh District (Greenville West, PA Quadrangle N:  41° 23` 02"; W: 80° 23` 36").

 To remove the existing superstructure and support pier and to construct and maintain a three span, through-plate-girder railroad bridge (Bridge MI-130.35) having a three clear spans of 105.0 feet, 42.0 feet and 105.0 feet respectively and a maximum underclearance of approximately 16.0 feet across the Shenango River approximately 2,000 feet NW of the intersection of Hamburg and Methodist Roads. Project includes: 1) repair of existing abutments; 2) construction of a temporary stone causeway and bents temporarily impacting approximately 0.248 acre of the Shenango River and associated back channel and scour pool; 3) permanent impact of 0.009 acre of the Shenango River and 0.005 acre of Shenango River back channel; and 4) impact of 0.011 acre of PEM wetland.