|Allan C Wirkkala posted|
Cable work. They did much with very limited equipment.
[This allows them to build the bents with the safety of being closer to the ground. I'm trying to figure out if it also allows some of the bents to be built in parallel, thus reducing the construction interval.]
[We can see the base of the boom of the travelling derrick at the top of the photo.]
[It is not clear to me how they raised the timbers up into position for this trestle.]
[Replacing or adding timbers would have to be done as "stick work."]