Turnbuckle adjustment to get the right tension on a cable is a pretty simple task.
With a wrench in the left hand place it on the left fork or eye fitting of the turnbuckle. With another wrench in the right hand, place it on the right fitting of the turnbuckle.
Now with the other hand, take a small rod, place it in the hole in the center of the turnbuckle barrel and turn it to get the proper tension.
What could be easier.
Wait a minute! If I count correctly that was three hands. The standard category hand count for the Stearman mechanic is two.
Not to worry. There is a tool out there that is called a “Turnbuckle Adjustment Rigging Wrench”.
This tool has a thumbscrew clamp mounted on each end of a 12 inch length of bicycle chain.
The clamps can move in and out from each other, but they can’t rotate with respect to one another.
So the procedure is to mount one clamp firmly on the left turnbuckle fitting and the other on the right turnbuckle fitting.
Now you can hold the loop of the chain in one hand and with the other (second) hand rotate the barrel with an appropriate tool.
This one was spotted and purchased on e-bay.
Aircraft Spruce has a similar tool in their catalog.
Worth looking into.