I just puchased a '75 Solcat 18 for parts for a '78. It has a third cross beam between the hulls forward of the mast and just aft of the bridle. Does anyone know what this is for? And was it original or something installed later?

Thought maybe it was for a forward tramp, spray shield, hull stiffener in the surf, or maybe just somewhere to step while raising the jib. Let me know.