Lary Bates:
Where stranded steel cable was used for rigging turnbuckles were used. The turnbuckle were most often located on the end of the cable that was attached to the lower wing for easy access for tueing the rigging. The RFC/RAF aircraft were rigged with RAF Wires, which were steel rod swaged to a streamline shape. These had left and right-handed steel clevis universal fittings at each end. By turning the swaged rod (wire) one way would tight the wire the opposite direction would loosen the wire. These were superior to the round cable inasmuch as they had a lower drag. The S.E.5a, Camel, Dolphin, Deh.4, etc all had RAF wires.
Blue skies,
Dan-San Abbott