IC - Buffalo Creek Bridge

Luke and Nathan,

Writing patents is a pain, I remember sitting with a rather pricy patent attorney and discussing more accurate words to replace 'at' in a draft claim. After about hour we settled on 'proximate' - it's now my most expensive word :^)

That being said, figuring out patents isn't that bad if you put yourself in the right state of mind. Start with the claims. At the end of the day, these are relatively easy to read. The independent claim is the basic and broadest idea with each dependant claim adding a tidbit or feature.

If what is taught in the independent claim is observed in the product (in our case the bridge) then it conforms to the patent. If it conforms to the dependant claims, that's a bonus.

The text and figures (drawings) support the claims and 'teach' how to use them. While they should be correct, they don't have to be clear (and the texts often aren't). The drawings are usually quite useful.

Looking at Linvilles 1865 patent, and the drawing Luke posted, you can go tihrougkh the details like how the cast panel point blocks are used. Such as the 'fingers' on the bottom panel points which are used to connect and space apart the lower chord components. Many of the details are unique to Linvilles bridges.

It's interesting to learn this stuff looking back 100 - 150 years as what is quaint today was intense back in the day! Keystone fought Phoenix all the way to the Supreme Court! Lowthrop defended the use of cast compression members with some pretty strong language but lost anyway. These were some pretty sharp guys pushing the bounds of state of the art technology in their day and they really did transform the county'.

Regards,

Art S.

I haven't the time to research this in the detail that Art and Jim Stewart have been, however in my understandings, I have always been guided by the idea that while we often refer to many bridges (like a Wrought Iron Bridge Company bowstring) as "conforming" to a particular patent, one must also remember that patents were NOT engineering documents, they were LEGAL documents intended to defend the interests and profits of the company. The actual designed and constructed bridges might vary from the patent, yet the companies that built them would nevertheless aggressively defend their bridges as patented designs. The actual design constructed in the field apparently did not need to 100% exactly replicate the patent to be defensible, only some features needed to be present.

According to this: https://books.google.com/books?id=IzsjAQAAMAAJ&pg=PA619&dq=p...

Reeves/Phoenix sued Linville/Keystone in 1872 over the truss patent. The writing is full of technical jargon, but does make mention of columns (Among other things.)

People like Art and Nathan are more in tune to decipher it, while it looks like cuneiform mixed with hieroglyphs to me.

I'd misread the source that mentioned Linville & Bollmann in the same breath.

Linville was the designer/engineer for the PRR (Not the B&O) starting in 1862, and stopping in 1865 when Keystone formed.

It's very unlikely that any of the spans in question came from the PRR.

Also,

Patent 34183 with its cast iron upper chord is pre civil war; 50723 is post civil war with Keystone Columns. This one and possibly one other govern the first generation of bridges across the Ohio and Mississippi rivers that Keystone did.

Regards,

Art S.

PS. When was Linville with the B&O? Could these recycled spans come from a B&O based bridge?

Luke,

The original bridges - yes. What is the evidence that these sections were from that bridge?

Regards,

Art S.

Here are two patents awarded to Linville.

This appears to be the original Linville Patent: https://patents.google.com/patent/US34183A/en?oq=USNNo.+34%2... ()

This appears to be the early/basic Linville & Piper varaint patent: https://patents.google.com/patent/US50723A/en?oq=US50%2c723

And you'd be wrong that Keystone didn't make it:

https://books.google.com/books?id=SC8jAQAAMAAJ&pg=PA33&dq=du...

And this Structuremag article says that Linville himself designed it, so I'm fairly certain that it's a further evolution of his own truss design, as Linville, like Wendell Bollman (Whom he replaced at B&O) he was fond of using his own designs over any other design:

https://www.structuremag.org/wp-content/uploads/2014/09/D-Gr...

Further supporting that idea is this historic article, which mentions Linville & Piper trusses as an option, so I think these may be smaller scale versions of the L-P truss, which I've yet to find a patent diagram for (And the article with the most info is locked behind the ASCE's paywall.

https://books.google.com/books?id=xY0yAQAAMAAJ&pg=PA23&dq=du...

Luke,

While I highly doubt Keystone made this bridge, it definitely does not conform to the Linville patents. The design details are different. The way the bridge, especially the lower cord is connected and rigged is very different than Linville.

To me this looks like Phoenix's version of a bridge designed to PRR's spec.

Regards,

Art S.

I'm fairly certain this bridge and the bridges at Janesville and Central City were built using parts from the original iteration of the swing bridge at Dubuque.

The bridge almost certainly reused from another location. The original endpost baes would have been cast iron. To my eye, the enposts look like Keystone Columns.

I agree with Tony. Looks like a mid 1870s structure that could have served as part of a much larger crossing at one point.

I think this is actually a railroad bridge...and an extremely early (ca.1870's) one at that.

The built-up endpost bases are very unusual.