Originally designed as a coastal defence gun, it was subsequently fitted to a ' De Stefano ' artillery carriage, named after the gun carriage's designer, and given the designation ' D.S. '.
June 1918, show front and back views of a massive Italian Army ' Obice da 305 D.S. ' standing on a road in the Italian town of Sandrigo in the Veneto region of N.E. Italy.
During the Obice's WW1 artillery service with the Italian Army, the De Stefano carriage's wheels were usually fitted with special tracks which were particularly beneficial in the snow and mud often encountered on the Italian Front. Those special tracks were ' Bonagente ' tracks, named after their inventor, an Italian Artillery Major, Crispino Bonagente.
The ' Bonagente ' tracks, first patented in September 1900, were fitted around the rim of the gun carriage's wheels, and were made up of a series of metallic plates on oscillating supports, with those plates greatly increasing the wheel's area of contact with the ground, thereby spreading the substantial weight of the gun over a much larger area, which was highly beneficial on soft muddy ground or in snow.
Another major feature of Bonagente's track invention, was that when the gun carriage's wheels came to a stop, the two plates closest to the ground came together to form a stable raised platform under the wheel, which allowed the gun to be immediately ready for firing, with the added benefit of the Bonagente track plates also absorbing some of the gun's recoil.
For more images of the Obice da 305 DS, see my post from a couple weeks ago http://justacarguy.blogspot.com/2018/01/many-years-ago-i-post-couple-photos-of.html