Due to the particular time period in history and the nature of trench warfare in general, artillery played a hugely important role during World War 1 (1914-1918). As both sides dug in for the long conflict ahead, the trench networks began dotting the eastern and western countryside of Europe in number and laid the ground work for the war in which tens of thousands could be killed on any given day. Artillery accounted for many deaths and proved just as effective against the new-fangled tanks being deployed by the British. Artillery in World War 1 - along with such evolving developments as the machine gun and aircraft - formed the framework of one of the bloodiest conflicts in European history.
Like the other world powers of the time, the Imperial German Army fielded a large collection of in-direct fire artillery weapons - from more portable trench mortars to the classic large guns like "Big Bertha" that have since gone into legend. During 1916, the German Army unveiled its latest area weapon through the 21cm (210mm) Morser 16 series gun - a howitzer essentially born from the existing 21cm Morser 10 series though now with a lengthened gun tube and protective shield. The type would serve into the post-war years after some use in World War 2. It was taken on in small numbers by both Sweden (12) and, later, Finland (4, by way of Sweden).
The design of the Morser 16 was based on a powerful 210mm (211mm officially, 8.3") barrel measuring 8 feet, 9 inches long. The original Morser 10s were short-barreled weapons with 8 foot, 5 inch barrels and, themselves, appeared as successors to the21cm Morser 99 line. The storied heavy metal works of Krupp once again worked on these newer German guns and added the longer barrel assemblies onto the requisite mounting hardware which was supported through a multi-spoked, two-wheeled carriage arrangement. The gunshield was added for some front protection for the gunnery crew. Like other artillery pieces, the gun became a heavy development - weighing some 14,730lb - and had to be towed either by "beasts of burden" or mover vehicles. This was facilitated some by the weapon being able to be broken down into two smaller, handier loads. The breech system was of a horizontal sliding wedge type and the recoil action handled through a hyropneumatic system. The carriage was of a box trail design and the gun mounting hardware held and inherent elevation span of -6 to +70 degrees. Traversal was limited to 4-degrees from centerline.
In practice, the guns gave the service expected of it. Each featured a muzzle velocity reaching 1,290 feet per second and area engagement ranges out to 12,100 yards. Each HE (High Explosive) projectile in use weighed 250lbs and "bunker-buster" concrete shells weighed as much as 270lbs. The projectiles carried a TNT filling for maximum firepower at the point of impact and shells used a separate-loading cased charge. Rate-of-fire reached up to two rounds per minute as reloading of the massive shells was a time consuming process. A gunnery crew would number many men and ammunition stocks had to be readily available prior to any planned offensive.
As production numbers and logistics allowed, Morser 16 series guns were in play wherever the German Army fought and stayed in circulation well after World War 1. The Swedish Army became an operator of the weapon through direct purchase during 1918 and eventually developed their own bunker-busting shells with better results at the point of impact. With the rise of the Nazi Party during the 1930s and the remerging Army service under Hitler, the guns were refurbished/modernized through implementation of steel wheels and trail limbers (additional wheeled support for the frame) for improved transport functionality. The gunshield was commonly removed to save on weight.
The renewed guns then fought under the Nazi flag for the first phase of the war before themselves being relegated to training and other second-line duties after the adoption of the massive 21cm Morser 18 series guns during 1939. During the 1939-1940 "Winter War" between Finland and the Soviet Union, the Finns purchased four Morser 16 guns from the neighboring Swedes but their inability to easily move the large weapons limited their usefulness in the conflict. It was not until the "Continuation War" of 1941-1944 that the guns were now made transportable within the Finnish Army inventory that the weapons were brought to bear on the Soviets.
Morser 16 guns managed only a short existence in the post-World War 2 years where they were all either retired, scrapped, or in storage by the 1960s. Final forms were Finnish-owned guns.