The Pittsburgh Press from Pittsburgh, Pennsylvania • Page 319

Superstructure of the 10th Street Bridge is deemed in excellent condition, but old trolley tracks show in deck where resurfacing has been worn away. With Appropriate Maintenance, The Span Could Be In Service Another 50 Years A I- I M- 'ill il Fa im I. ijm mm 0 I 0 mm jp ft i -Wb i 4 iV whom and dirt completely blocks remaining ones. Roadway water pours through expansion dams ana holes which have eaten through the curbs. The water has badly rusted secondary steel supports called stringers" and transformed ''caps" on the granite piers from solid concrete to as much as 80 per cent loose aggregate.

A dozen wires in a 256-wire strand of cables are broken and water seeping into the massive anchorage vaults has eroded as much as 25 per cent of some cable anchors. The old trolley tracks remain ensconced in the bridge deck and can be seen because 70 to 80 per cent of the last asphalt resurfacing job has disappeared. You can also see 7-foof-long holes in the curb and reinforcing rods sticking out of concrete. "The concrete-filled tee-beam grid has broken loose from 50 to 60 per cent of the length of the supporting transverse stringers' the frightful-sounding analysis reads. "At many locations, the deck has risen off the stringers in amounts varying from 11 6 th to 1 inch and motion of the deck takes place as traffic passes over the structure." Sidewalks on both sides of the bridge have buckled as much as 10 inches because of (a) the design, (b) lack of expansion joints, (c) engineers miscalculating the bridge height by .4 of an inch in the 1930s or (d) all of the above.

No one knows for certain. The two tall steel towers were found to be "in very good condition" despite some corrosion, heavy accumulations of pigeon dung from birds which roost in the interior and two missing access doors. On the sidewalk support steel, leaking water caused 90 per cent of a flange to rust away. The flange had been repaired in the past, but the repair also broke loose. Someone cut away another flange "for some unknown reason" and never replaced it.

In the bridge electrical system, light switches are in violation of the National Continued On Next Page It' 1 33.