21cm Lange MORSER M-16/ L14.5
Based on the previous models of 21cm howitzers, (mortars in german terminology), the 1916 model “21cm Lange Morser M.16 / L14.5” was a new design made jointly by Rheinmetall and Krupp to get more range lengthening the tube from 12 to 14.5 calibers. The range was improved in about 800 meters only, because one of the main objectives was not to increase the total weight of the piece, objective met with the increase of only 177kgs. The 14.5 caliber tubes were mounted on more than two hundred 21cm Morsers that German Army had at the beginning of WWI. It was still in use when WWII broke up and 28 examples were modernized with rubber tyres to facilitate its movement on the battlefield.
Lange MORSER M-16 gallery and more info