Construction this week on the new Tacoma Narrows bridge:
Spinning crews finished up the south cable Tuesday and are preparing for the next phase of construction: compacting and binding.
First, though, Tacoma Narrows Constructors crews will finish swapping out tower cranes on both towers. The big cranes that have been in place since tower construction began are attached to the tops of the caissons. They need to be moved to make room for erection of the bridge deck.
The new cranes are being attached to the top struts of the towers. Crews put the new crane on the Tacoma tower last week.
This week, if the wind stops long enough, they’ll dismantle the old Tacoma crane and set it up on top of the Gig Harbor tower. The existing Gig Harbor crane will be dismantled and hauled off to another job.
Crews have taken out the tram rope that ran the cable-spinning wheel on the south side, and this week they’ll finish taking out the steel cable formers that allowed them to put the wires into the right positions as they built up the cable.
The new cable wire is on track to be delivered in March. Spinning the north cable will resume then.
I’ve been reading about the cable for the bridge and there hasn’t been a word about twisting the cable. In all the pictures the wires are straight. When does it get twisted into a cable? A cable in my mind has to be twisted for strength.
The 8,816 wires in the main cables don’t need to be twisted to attain their strength. They’ll run parallel to each other and be wrapped to form the cable.