Interestingly enough, in somewhat typical PENNDOT fashion, there is a disagreement about the significance of the Birmingham Bridge.
HAER describes the bridge’s significance: http://lcweb2.loc.gov/cgi-bin/ampage?collId=pphhdatapage&fil...
“This single span pin-connected Pratt through-truss is unique for a Pratt truss in that the portals contain hip verticals that carry compressive stresses (hip verticals for the standard Pratt truss type carry tensile stresses only).”
On the flip side, PENNDOT notes in the PA Historical Bridge inventory, “The lower panel point has been changed significantly with the original hanger replaced with riveted connections to plates attached to the verticals. The floor beams appear to have been replaced when the connection was changed. The bridge is an altered example of a type and design that is well represented in the region and state. It is not historically or technologically significant because of the alteration to the lower panel points.”
Whatever camp you sit on you can no doubt appreciate the beauty and uniqueness of the portals at both ends of the bridge which feature decorative panels containing clover-leaf cutouts in the web section of the lateral bracing.
I should point out that the name of the road the bridge carries is called “Irish Flats” so one can assume the clover leaf cut-outs on the top chord might be related. Four leaf clovers represent good luck which might be why this forunate bridge is still standing.
Birmingham Bridge rests on abutments with wingwalls made of cut-stone sandstone also known as ashlar.
The bridge consists of compression members of steel channel sections and riveted lacing bars; and tension members of forged steel eyebars. A diagonal compression member extends from the junction of the lower chord and hip vertical to the main portal member. Steel I-beam floor beams and strings support the 3” thick plank on steel stringers and beams wooden deck.
Based on the inscription on the masonry abutments the bridge was built in 1898. This metal bridge replaced a wooden bridge constructed in 1852. When the through truss was built it included a pedestrian sidewalk on the downstream side but was later removed for reasons unknown.
Currently the bridge serves a single residence on the south side of the Little Juniata. The present owners are Blair and Huntingdon Counties (Blair County assumes actual responsibility for maintenance and both counties share cost equally). Bridge was sandblasted and painted in 1987.
Whether this bridge is considered significant is debatable, I for one am crossing my fingers in hopes that neither man nor Mother Nature remove this beautiful piece of work.
Thanks goodness it's on a dead end road. If it wasn't the "BUTCHER" of historical bridges PENNDOT would have needlessly destroyed it by now.
PennDOT wouldn't know a historically significant bridge if it bit them in the A**!!!!!!!!!!
This is a very unique bridge, enough so that it is HAER documented. HAER didn't offer much of an explanation for the unusual design, but either way it did catch their eye too (as well as mine). Sometimes I think there is history we don't know. Maybe there was a quarry or something on the other side long ago, and they needed a heavier bridge.
Nice bridge Jodi!
Has the look of a railroad span......until you look at the inside clearance.....which seems to be too low.
Am guessing the dead-end road is the only thing that has spared it from PennDOT's grimy paws.
Blair seeks historic bridge repair bids
Local News
Feb 12, 2020
Kay Stephens
Staff Writer
kstephens@altoonamirror.com
HOLLIDAYSBURG — Blair County will solicit bids for repairs to a historic bridge on Irish Flats Lane in Tyrone Township.
Commissioners approved the action Tuesday, as recommended by Brian Wiser of Keller Engineers, who said the bridge’s weight limit used to be 15 tons. The weight limit was reduced to 6 tons, he said, after the truss deterioration was identified.
By taking on the proposed repairs, the county can avoid additional weight restrictions or the need to close the bridge, according to Wiser.
The bridge, which spans the Little Juniata River, provides access to three Tyrone Township properties — two with residences — on the Blair County side of the bridge. The bridge is the only way to access the properties. The other side of the bridge is in Warriors Mark Township in Huntingdon County.
After the bridge’s weight restriction was reduced, Wiser said fuel oil delivery companies had to resort to deliveries in smaller trucks to those residences.
County Administrator/ Chief Clerk Nicole Hemminger told commissioners Tuesday that the county has money in an account set aside for bridge repairs and in another account that could be used for bridge repairs or other transportation-related expenses.
She declined to reveal the estimated cost for the project, in light of the pending bid process.
Depending on the bids received and the allocation of money to cover the cost, the county could be in a position to issue a notice to proceed with construction in late March or April, she said.
Wiser also mentioned that the bridge, built in 1898, features decorative four-leaf clover cutouts on the upper portion of the 142-foot span.
The bridge is on the National Register of Historic Places in Pennsylvania and monitored by the Pennsylvania Historic and Museum Commission.
Mirror Staff Writer Kay Stephens is at 946-7456.