Wall system

A wall structure comprising a plurality of courses of substantially rectangular building blocks of substantially uniform height, the blocks in each course being offset longitudinally a distance equal to one-half the length of a block with respect to blocks in adjacent courses, each block having means for use in interlocking the block to other blocks in the same course and to blocks in the adjacent lower course, the interlocking means being located in at least one endwall of the block and in the center of the block, and at both locations extending the full height of the block, the interlocking means in the endwall of each block comprising a vertical dovetail slot positioned centrally of the endwall and tapering uniformly down from the top to the bottom of the block, each slot being adapted to confront another, substantially identical slot in another block of the same course, and the interlocking means in the center of each block comprising a centrally positioned through vertical opening having the shape of two of said dovetail slots positioned in face to face relationship, said opening tapering down at the same angle from the top to the bottom of the blocks as said dovetail slot, the dovetail slot at the bottom of each block having a size equal to about one-half of the size of said slot at the top of the block, and said vertical opening having a size at the top of the block equal to about the size of two of said dovetail slots positioned in face to face relationship at the bottom of said block, said blocks, said slots and said openings being dimensioned so that when placed in adjacent courses the axis of each confronting pair of said slots in aligned with the axis of one of said vertical openings, and removable locking pins made from the same material as the blocks and having straight sidewalls tapering at the same angle as the interlocking means and cooperating therewith, each locking pin having the complementary shape of two dovetail slots positioned in face to face relationship and a length substantially equal to the height of two of said blocks, each locking pin having a size at its large end about equal to the size of two of said dovetail slots in face to face relationship at the top of said block, and a size at its small end substantially equal to the size of the opening at the bottom of the block, said tapering locking pins being adapted to be inserted into said aligned tapered slots and openings and driven home to form a wedge fit, with the straight sidewalls of said pins in frictional engagement with the walls defining said aligned slots and openings.