Tiger I nickname "Tiger" by Ferdinand Porsche, and the Roman numeral was added after the later Tiger II entered production. The initial designation was "Panzerkampfwagen VI Ausführung H" (‘‘"Panzer VI version H"’’, abbreviated "PzKpfw VI Ausf. H") where 'H' denoted Henschel as the designer/manufacturer. It was classified with ordnance inventory designation "SdKfz 182". The tank was later re-designated as "PzKpfw VI Ausf. E" in March 1943, with ordnance inventory designation "SdKfz 181". Today, only seven Tiger I tanks survive in museums and private collections worldwide. The Tiger 131 at the UK's Tank Museum, which was captured during the North Africa Campaign, is
503rd Heavy Panzer Battalion brought back to Germany. In September 1944, the refitted 503rd took part in the Battle of Debrecen. In early-November, the battalion provided a mobile reserve for the 6th Army (Wehrmacht), re-designated as Army Group Hermann Balck. By mid-December, the German forces had been pushed back to Budapest. The unit took part in several failed attempts to relieve Budapest, codenamed Operation Konrad. 503rd Heavy Panzer Battalion The 503rd Heavy Panzer Battalion (; abbreviated: "s.Pz.Abt. 503") was a Nazi German heavy Panzer "Abteilung" (independent battalion-sized unit) equipped with Tiger I and Panzer III tanks. In 1944, it was re-equipped with the new