Sumpter appeared to have a single blade semaphore...this could be used to signal in either direction, I suppose...Interesting.
It also appears to be the "cable operated" type where the counterweight held it in the horizontal or "stop" position, and the operator hauled down on the cable and hooked it somehow to move it to the "clear" position
I find old depot pictures showing the various types of train order semaphores fascinating.
There were all kinds of devices used...upper quadrant, lower quadrant, The "swift" type of
rotating signals, and all that. Some places just used colored lights for T.O. signals mounted on a "target" mast like other similar trackside signals.