The wooden tower in pic 91 is called a telltail and you are close in your guess as to it's purpose though it's not rolling stock related.
A telltail goes back to the days before the early 1970's when freight cars had roofwalks along the top of the cars.
Anywhere the tracks might pass under a low overhead clearance such as a tunnel or in this case the bridge trusses the railroad would erect a telltail, if a brakeman happened to be walking along the top of the train and he felt the ropes of a telltail hit him he knew he had seconds to either climb down between the cars or to flatten himself out on the roof.
FRA (Federal Railroad Administration)regs where changed back in the very late 60's/early 70's to ban roofwalks thus relegating the telltail to a historical oddity.
Took pictures I believe last November. As for responses from historical societies and or the Library, nothing going so far, I have called and left messages and sent emails kind of annoying. I actually got most my Info from a L&N Railroad Forum board in the last few days. They found the bridge interesting even though it turned out it was not L&N, but Elizabethtown Paducah Railroad and Illinois Central Railroad. I have been hitting the Google Books looking for information and nothing really. I did find another bridge built in the 1930's on the same line that replaced a bridge built in the 1870's over the green river in ohio county, that is now on the Paducah Louisville line. So that confirmed the age range. But really looking for that builder.
Totally unique find guys!! Hey J.P. when did you take those pictures? Also hows the wait for responses going? I haven't seen a bridge like that before...it's built so differently...I think your right two different companies built this bridge...it doesn't seem to have the same design as other trestles in Kentucky or Virgina either...Nice Find!!
I have contacted every possible historical society in Hardin County looking for information on this bridge. Now the wait for the answers. Now as for info i think i might have figured out. First im going this bridge was built during the 1880's mainly after the civil war and retreat of the south from kentucky. As they destroyed every bridge on the L&N railroad between louisville and Tennessee. Next I have noticed usually the Phoenix Iron company just provides the columns, so i bet there is a second company involved in the building of this bridge. As i said these are guesses, ill know more when i get some answers. As you can see i found the patent information from 1862
And the floorbeams are back-to-back channels with v-lacing?! Never seen such a thing.
That bottom chord is built up like a girder! Very impressive.
WOW!!!! I have never seen a bottom chord, floorbeam, and deck system like this! The bottom chord is more massive than the floorbeams.
I, and fellow Bridgehunter J.P., just happened to find this wonderful "Pheonix" bridge almost by accident.