Wrenchguy's on the right track, no pun intended. It's a track wrench. Brings back memories of a mispent summer on the railroad long, long ago. How long ago? It was on the Milwaukee Road. It's called a speed wrench. You put it on the track bolt nut, get as much of a turn as you can and slip it back until it grabs again. Repeat and repeat again until it's time to break for lunch. Turns out a company in Ohio, Railroad Tools and Solutions, still makes them. They call it a a speed wrench/ratchet action wrench.