The contraption that uses a fixed bottom and sliding upper, be it chisel, shaper or etc. is called a guillotine tool. Did a quick google, saw a couple of likely things. The sliding upper uses a pair of guides, one on each side, with it open on top to change tools, so the tool has to protrude above the top plate. Overall they measure figure about 6-7 inches wide, and about 9 tall. It usually fits into the hardyhole, or in a pinch can be locked in a vise. Most guys make their own from 1/2in. plate. They arc weld the assembly together, because it does take a lot of beating. The splitting term, never heard it, is more likely called cutting, hot cuts or cold cuts. A well tempered cold cut can be used to cut up to 7/16 round stock, a lot faster than a hacksaw. Lay your piece on the mark, strike smartly, turn a quarter, strike again, about 3 hits and the piece can be separated.