The Versuchsträger 1-2 (abbreviated: VT, meaning "test-beds" or "experiment carrier") were two German prototype twin gun turretless main battle tanks. Since the early 1970s a number of West German companies have been working on conceptual designs for a successor to the Leopard 1. This project had the name Kampfpanzer 3 (KPz 3). The KPz 3 project was temporarily a British-German joint project, until the UK withdrew because they wanted a turreted tank.