Friday, November 11, 2022

1929,1997 Tacony-Palmyra Bridge over Delaware River at Philadelphia, PA

(Bridge Hunter; no Historic Bridges; 3D Satellite)

3D Satellite
James Loesch Flickr via BridgeHunter, License: Creative Commons Attribution-Share-Alike (CC BY-SA)

This bridge was designed by Ralph Modjeski. The vertical clearance at high tide under the center of the arch is 61' and under the bascule span is 54'. It has two lanes into Philadelphia and one into New Jersey. It also accommodates pedestrians. The pony trusses are continuous. [1929 is a very early date for continuous truss designs.]

iis Engineering via BridgeHunter

Postcard via BridgeHunter
Span lengths:
Arch: 523' (159.4m)
Bascule: 247.5' (75.4m)
Each Pony: 232' (70.7m)
This source says the vertical clearances are 64' (52.7m) and 54' (16.5m).
The toll is westbound only and $4 for cash and $3 for EZ-Pass.
The grade on the side spans is 3.4%.
The number of lanes was reduced from 4 to 3 during a 1997 deck replacement project.
A ferry service with two ferries (Tacony and Palmyra) was started on May 6, 1922 because this was about half way between the ferries at the site of today's Benjamin Franklin and Burlington-Bristol Bridges.
Michael Froio Photography posted
Outbound bulk carrier Pacific Merit eases toward the Tacony Palmyra Bridge on the Delaware River. The Hong Kong flagged vessel is en route to Barcelona as it makes its way out of the Delaware Watershed toward the Atlantic. New work from an ongoing project exploring the post industrial waterfront of the Delaware River in Philadelphia with @timkerner.
Artist in concrete and steel - Bridges of Ralph Modjeski posted
Tacony Palmyra Bridge with open bascule span for passage of ocean-going vessels.
Douglas Butler posted
Joe Kane posted
Reporting for the Philadelphia Evening Public Ledger Vivian Shirley (in heels) on the Tacony-Palmyra Bridge - 1929
Bridges Now and Then shared

Normally, trusses are deck or through. The use of pony trusses of this length is unusual. But they allow us to easily see they were constructed with built-up members and rivets, which is expected for 1929. I'm amazed that they stop the traffic on the bridge so close to the movable span. The DelawareRiverHeritageTrail photo below confirms that some big ships pass through this bridge. If a ship misses the opening and allides with the fixed span, some drivers are going to have a bad day. The Free Grosse IIe Bridge moved the traffic lights from the bridge back to the shore because a fixed span did get rammed. The shore is a long way away for this bridge, and such a move would add more time to the bridge closure. So I think the compromise of putting the signal on the span before this one would be appropriate. If a ship misses the opening by more than 232', then something went terribly wrong.
After I wrote the above, I discovered in Apr 2018 a southbound ship did allide with the bridge. Fortunately, it hit a dolphin fender. Nonetheless, it caused the bridge to be closed for five hours. [CourierPostOnline] "The cause of the collision remains under investigation. Officials are trying to determine if the strong, gusty winds that were blowing around that time played a role in the accident." [NBCphiladelphia] So with proof that accidents can happen in 2018, they still have not moved the stopped traffic away from the movable span in 2022.
(Update: the owner of this bridge also owns the Burlington-Bristol Bridge further upstream. In contrast with this bridge, that bridge does not stop the traffic on the bridge. In fact, on the east side, traffic is stopped far from the shore. So why is the same owner so conservative with that bridge and so reckless with this bridge?)
Street View, Sep 2022

"Construction began in February 1928 and the new bridge opened to traffic in August 1929, a mere 18 months and $4 million dollars later. The fare was 35 cents and an average of 3,500 cars a day made the trip; in five years the number of vehicles doubled. Today, approximately 70,000 vehicles per day use the bridge."

Media Assassin!, Oct 2018

January 1929: Erection of bascule span, which operates like a balance or seesaw—the rising floor section is counterbalanced by a weight; two rolling lifts power the bascule span.



The bridge was rehabilitated and painted in 2018-19.

No comments:

Post a Comment