Although the early German "Panzerjäger" carried more effective weapons than the tanks on which they were based, they were generally lacking in protection for the crew, having thinly armored open-topped superstructures. The "open-topped" design format of the "Panzerjäger" vehicles was succeeded by the "Jagdpanzer" ("hunting tanks"), which mounted the gun in true casemate-style superstructures, completely enclosing the crew compartment in armor that was usually integral to the hull. The first of these "Jagdpanzer"s was the 70-ton "Ferdinand" (later renamed "Elefant"), based on the chassis, hulls, and drive systems of ninety-one Porsche VK4501 (P) heavy tanks, mounting a long-barreled 88 mm cannon in an added casemate, more like the earlier "Panzerjägers" had with their added-on armor shielding for the gun crew, but in the "Ferdinand" completely enclosing the gun and firing crew in the added casemate, as the later purpose-built "Jagdpanzers" would. However, the "Ferdinand" was mechanically unreliable and difficult to maneuver, and once all ninety-one unturreted "Porsche Tiger" hulls/drive systems were converted, no more were built. The German Army had more success with the Jagdpanther. Introduced in mid-1944, the Jagdpanther, of which some 415 examples were produced, was considered the best of the casemate-design Jagdpanzer designs. It featured the same powerful PaK 43 88 mm cannon used on the unwieldy "Elefant", now fitted to the chassis of the medium Panther tank, providing greatly improved armor-penetrating capability in a medium-weight vehicle.