Note the lower spreader lifts and down-hauls, the double jumper struts and the diamond rig (the upper shroud returned to the mast). This photograph and the one on the opposite page were taken from the deck.
Note on the opposite page that the spreader lifts and diamond rig have been discarded, and that a single jumper strut has replaced the double one. The tracks and blocks on the lower part of the metal mast are for raising the inboard end of the spinnaker boom.
Compare the slimness of the metal mast and spreaders with the wooden one. Note particularly the difference in the small horizontal stays between the starboard and port spreaders. These stays hold the spreaders fixed to the wooden mast, but in the case of the metal mast they connect the spreaders to each other, leaving them free to swing together fore and aft.

From the book :

Enterprise : the story of the defense of the America's cup in 1930