After a bit off woodwork I've made a start on the shipboard derricks. These are just a 6mm main mast, with 4mm booms pinned to the mast with short bits of bras rod.
Now to answer the question in the last posts comments.
I'm not planning to have is visible from the backside as I have a plan to put the point throws in the guts of the ship and run the wire through to under the wharf.
Now, if I could just find a local supplier of 3-4 bags of Pecos track pins (they are useful for so many more things than pinning track).