Public Domain: Published Prior to 1923
BH Photo #429518
Found the jackpot of information, the tough part is access.
This bridge is located in Illinois Central valuation section WI-2. Complete circa 1917 bridge records can be found in College Park, Maryland:
In addition, the National Archives appears to have a complete set of bridge records for the entire IC system. These will likely provide a complete description and build date of the structure. Since this route was originally built by the Chicago, Madison & Northern, construction cost records between the 1880s and 1903 (Box 15, Folder 100/101). This source also seems to have a limited amount of IC bridge and culvert information, including contracts with Keystone Bridge Company for the Dubuque bridge:
In addition, there are inspection photos of Illinois Central bridges available at the University of Illinois
Valuation maps from the same year show that four more of the 122' trusses existed (two near Dodds, one confirmed identical span near Argyle, and one near Blanchardville). This mystery is certainly possible to crack.
It's worth noting that John and I have been searching for confirmation on the link for a while (>2yrs), to no avail, but design cues + proximity, as well as the fact the owning bridge company sold off the 1870s Pratts after replacement gives both John & I a solid basis for our hunch.
Iíve been searching for something to conform or deny the possibility it came from Dubuque. An Illinois Central valuation map from 1918 gives the stations of these trusses, which are a pair of 122í spans. However, the spans in question were seen at the bottom of the river in the 1911 photo. Is it possible they were saved and rebuilt? Is it possible they could have been ďcut downĒ from 250í (length of the Dubuque spans) to 122í? Or are the 122í measurements from the valuation map for a replacement bridge? Preliminary research has been unsuccessful in confirming or denying it. There are however quite a few trusses that were on this branch line.
Information supplied from official railroad blueprints for various railroads certainly provides the possibility for unique situations. Iíve seen blueprints of bridges lengthened, strengthened, shortened, converted between deck and through trusses and girders, and many other unique situations. Railroad engineers were very creative, giving us a plethora of unique structures. Unfortunately, many of these ended up on branch lines which were removed and the bridges scrapped.
The portals and design would seem to match the Dubuque bridge. Some bridges used very unique designs not seen on other bridges. Could this be one, or was it a standardized design to an extent?
Iíll look into and see what records I can find for this railroad. However, it may be hard to find pre-1911 information. It really varies by company. Some Iíve had tremendous luck on (Milwaukee Road, Chicago & North Western, Santa Fe, etc). Iíve also had some railroads with zero luck (Rock Island).
The original bridges - yes. What is the evidence that these sections were from that bridge?
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:
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:
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.
While I highly doubt Keystone made this bridge, it definitely does not conform to the Linville patents. The design details are different.
(Condensing multiple posts into one.)
An 1869 article in the Railway Locomotives and Cars, Volume 42 explicitly states Keystone, and a later publication from the Journal of the Western Society of Engineers and an HAER document on one of the 1870s approaches cite Keystone as the builder of the 1868 spans.
Railway Locomotives & Cars Article (1869):
Journal of the Western Society of Engineers Article (1908):
HAER documentation on a relocated 1870s Pratt:
The photo appears to show Phoenix Columns. Perhaps Keystone Bridge Company erected the bridge, but purchased the Phoenix Columns from Phoenix Bridge Company. Maybe they purchased raw columns and used them for their own fabrication, which might explain the portal looking like Keystone's design. The company did indeed sell the columns individually. Note that the connection detail between columns is unusual, they are not the castings used by Phoenix Bridge Company. This further suggests a possibility that the columns were purchased by Keystone with other bridge fabrication carried out by Keystone. On the other hand, if Keystone did fabricate these columns, we would be looking at a patent violation.
Regardless of builder, these were unique spans. This bridge reused two spans,and there were two spans in Linn County Iowa that were replaced in the 20s. This leaves one or two 1868 spans unaccounted for. With some of the 1870s spans ending up in Mississippi, the unaccounted spans could have ended up virtually anywhere in the central US. However, I doubt they still exist.
I realized that I missed your point - the bridge was manufactured in 1868, relocated in 1900 and washed out in 1911. That timeline makes sense.
It still wasn't made by Keystone :^)
I failed to mention this. The 1872 spans added to the Dubuque bridge were keystone spans. I agree that the spans arenít Keystone. More research is required to find who indeed built the 1860s spans.
The compression members in the photo are Phoenix Columns. Keystone (Carnegie) fought Phoenix all the way up to the Supreme Court regarding the column patents. I highly doubt they would use their competitors products.
The bridge was built using spans relocated from Dubuque, Iowa. They were originally fabricated 1868.
Keystone is unlikely as the builder as the bridge was made using Phoenix Columns. Also, the build date is considerably earlier than 1900.