1875 Portageville Bridge construction vs 1900 Kinzua Viaduct

In reference to the original " Portageville Replacement " thread I was looking at 452 Card's post on 1-29-18 of his picture of the bridge support plate

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A TV segment of " Mysteries of the Abandoned " recently that featured the demise of the Kinzua Viaduct in PA. That program pointed out how in 1900 the original wrought iron structure was replaced by a steel structure ( in 94 days ). Engineers in that program pointed out how everything was replaced in that conversion except the original pins anchoring the supports to the piers which they theorized snapped when hit by the tornado winds.

Which brings me back to the pics as posted by 452 Carr of the piers on the Portageville Bridge. Hard to now imagine these bridges were " only' anchored by pins.

I realize a simplistic observation but still..................
Mark

Pins, but not small ones.

The dead weight of the structure does most of the work and it is a downward force on the foundations, which have pins or bolts, or some kind of fastener. There tends not to be any upward force on a bridge structure other than wind.