At the beginning of the XXth century, a new technologic revolution shakes the artillery science, with the apparition of brake / recuperator systems 'on board' allowing to considerably increase the fire rates by avoiding to re-aim the guns after each shot. germany quickly understand the importance of this evolution and modernises most of its weapons with the help of the powerful Krupp and Ehrardt companies.

But this technology is coplex, and requires numerous tests and settings. In the case of the 21 cm mortars, not less than 3 Krupp prototypes produced from 1903 will be needed before transitioning from the 'old' 21cm Morser M1899 to the famous 'Morser', 21cm Morser M1910. The last of these prototypes, 21cm VersuchMorser L/10 Nr 3, , also named 'Vers. Mrs. Nr. 3 ständig langer Rücklauf' appeared in 1906 and is produced in a small serie of 8 specimens for the creation of 2 batteries that will be tested 'live' during peace time manoeuvres and perhaps used during the war.

The insufficient range (7000 m) of this prototype will be increased up to 9400 m and its impressive weight of almost 8 tons lowered to 7380 kg with the 21cm morser 1910 that equipped the German FussArtillerie in 1914.

Main characteristics :

• Weight in firing position : 7943 kg
• Calibre : 211 mm
• Tube length : 10 calibres
• Projectile weight: 120 kg
• Initial velocity : 367 m/s
• Maximum range : 7000 m
• Elevation range : +6 / +70 degrees
• Direction range : none