This is at the early portion of this FC list's era.
What were the advantages of clasp vs. more-modern FC brakes . . . over just adding fifty-percent more to doubling the pads? Many six-wheel trucked cars used these in the 1920s. When did they disappear on North American FCs (currently used on high-speed pass loco's)? Did the CD vs. AB brake schedule change their advantages? Did they made it harder or easier to balance clamping pressures. They appear to have violated the KISS principle, and made the truck assemblies longer and heavier.
