Three X Types were built: L70 was Zeppelin build number LZ 112; her sister ship L71 was LZ113; and what was to have been L72, build number LZ114, was not completed until after the Armistice and was awarded to France as war reparations. The French named LZ114 "Dixmude".
L70 and L71 as built were identical with seven Maybach MB IVa "altitude motors", including two in the rear car driving a single propeller. There were six propellers in total: one on the control car, one on each of the four "wing" cars and the one on the rear car (driven by two engines). This arrangement made them the most powerful and fastest Zeppelins so far built, but by this late stage in the war it was the ability to reach ever higher altitudes that had become the most important performance feature. And so just two months after L71 was commissioned, she was lengthened by the addition of one 15 meter gas cell bay and lightened by being given a smaller, single engined rear car, thereby reducing the engines to six, still with six propellers . LZ114, the Dixmude was completed with the 15 meter extension and the same single engine rear car as L71. A particularly noticeable feature of the X Type design was that the tail-fins and tail-planes were self-supporting, cantilever structures. This innovation had been prototyped on LZ111 (L65), the last of the V Types built.
L70 was an outstanding airship and with her, Friedrichshafen attained the peak in military airship performance. But fate dealt the airship a cruel blow: the Commander and driving spirit of the German naval airship fleet, Frigate-Captain Peter Strasser himself, was on board L70 for what was to be the last airship raid against England of World War 1. On the night of 6 August 1918 a British DH4 two-seater biplane caught L70 unawares at lower than her normal attack altitude. The plane's machine gun ammunition was the "Pomeroy" exploding bullet type and it was seen to blow a fiery hole in the fabric of the lower hull of L70 about 3/4 of the way aft. In under a minute the entire ship was engulfed in flames, her nose reached into the sky before she fell tail-first, blazing from stem to stern into the North Sea off the English Norfolk coast, killing everyone on board.