This is seemingly highly uncommon in pony truss configurations like this, but it's much more common in deck trusses, particularly approach spans as on the BNSF's Rock Island Bridge:
The deck is on top of the structure rather than passing through it, but all in all, both structure types appear to be constructed to handle loads in exactly the same manner. Very cool to see this in a pony truss!
I totally agree Nathan...definitely not a bedstead.
This looks similar to an August Borneman 1879 patent that I believe was referred to as a "Suspension Truss". Several of these were built in and around Fairfield County, Ohio but I'm not sure that any remain.
Definitely very rare and unique!
This is a beautiful and fascinating bridge and one of the most interesting I have seen. However, I don't know that I would describe it as a bedstead. It appears to me to be the opposite of a bedstead truss. Instead of having a superstructure (end post) that extends below the roadway, reducing the size of the substructure, this bridge appears to have a superstructure that reduces the size of (actually eliminates) a traditional end post and instead has a substructure that extends above the deck to meet the bearing location which is well above the roadway.