At the beginning of the war, the German long 15 cm tubes were reserved mainly to the Navy or the fortress artillery.The improvised long range guns, such as the '15 cm i.R. L/40', that were developped with these tubes in 1915 were so successful that it was asked to both companies Krupp and Rheinmetall to propose new long range heavy 15cm guns.

Tested in 1915, the proposals of the both companies were adopted and delivered to the front from 1917. At the end of the war, although, only 32 15cm Rheinmetall had been produced, compared to the 214 Krupp '15 cm Kanone M16'.

Krupp design was directly made for a mechanical towing in a single load, while the Rheinmetall gun could be transported either in a single load by a mechanical tractor, or in two separate loads with horses.

Main characteristics :

• Weight in firing position : 10140 kg
• Calibre : 149.3 mm
• Tube length : 42.7 calibres
• Projectile weight : 52.5 kg
• Initial velocity : 749 m/s
• Maximum range : 22800 m
• Elevation range : +42 degrees
• Direction range : 8 degrees