Switchman attaching screw coupling on to hook, tightening coupling, and leaving vehicles. The coupling operation could be done in under 30 seconds; however, with a train of 60 wagons, that still entailed at least half an hour of work for coupling or uncoupling, which was an impetus towards using center-buffer couplers which could couple automatically, reducing the time to couple an entire train down to about 10 minutes (most of it being taken in coupling the brake pipes). "Railway and locomotive engineering : a practical journal of railway motive power and rolling stock" (1900s). Scan from the Internet Archive of Book Images. (Admin)