In the early 1950′s Tow motor (later Caterpillar) developed a machine to rotate the load a full 90 degrees much in the same way as modern articulated trucks. However, the truck retained all other counterbalance design characteristics so it required two rotating hydraulic support legs that were activated when stacking on either side of the truck. The “Narrow Aisle Stack” was a relatively successful machine as it facilitated 6′ aisles. Linde and Still were amongst others that had filed patents on articulated machines.