A system of brake rigging where a brake block is applied to each side of a wheel tread. In essence, the wheel is "clasped" by a pair of brake blocks. Sometimes referred to as "double-block" braking. Normally such designs are arranged so that the two blocks are linked by the rigging and act together but some have individual brake cylinders for each block. In such a case, a 4-wheeled bogie would have eight brake cylinders and a 6-wheeled bogie would have twelve brake cylinders.