The station at Workington is within the block section between Workington Main No.2 and Workington Main No.3 signal boxes. Since its absolute block, each line is only signalled in one direction.
Trains will be entering the down platform, and being allowed forward to signal 24 (which protects the bridge). They can then use the crossover (31 and 28 points) under the authority of shunt disc 34 to head to the up platform.
Here's a diagram that was within the 1984 resignalling of Workington Main No.2 signal box, its still quite accurate but much of the infastructure has been disconnected.
View attachment 153628
I suppose one of the issues with the closure of the bridge is that it means Workington No.3 signal box needs to be staffed outside of its usual hours - its normally switched out in the early morning and late nights, and on Sundays!