The design of the giant howitzer was started by Skoda Works in 1915. In 1914, to defeat the Belgian forts, the Monarchy sent 30.5 cm mortars to the Western Front. These were generally well-proven, but one of the armor domes withstood a direct hit. Therefore, it was decided to increase the barrel size and penetrating strength of the projectile. Although, by this time the 42cm howitzer was ready, but it was designed to be built into fixed position. Thus, plans were made for a large-caliber mobile cannon. Under the leadership of Ferdinand Porsche, a special petrol and electric driven vehicle was designed to transport the 4-part cannon, which was suitable for both road and rail transport. Construction of the first two cannons began in June 1915. The name of the top secret development program was BHL / 17 as it is seen on the badge. The first test shots were fired in January 1916 with the new artillery device.
In 1916, during the Tyrolean offensive of the Monarchy, the first two guns saw first action. These were the cannons named Gudrun and Barbara. Barbara was on the Costalta Plateau and Gudrun in the Etsch Valley near Rovereto. The main target of the Barbara cannon was the armor of Punta Corbin, Gudrun’s were Coni Zugna and Col Santo. The cannons were used successfully in the attack. Later a total of 10 38 cm siege guns were built at Skoda Works in Plzen. The later devices were also intended primarily for the Italian front. More details about the cannon can be read here.
Technical data: barrel length 646 cm, caliber 38 cm, fire rate: one shot every 5 minutes, angle of vertical movement: + 40- + 75 degrees, maximum shooting distance 15 km. The cannons were organized in pairs per battery. There were 8 officers and 210 handlers in each battery.
The photo attached to the post shows one of the first two cannons installed. In the color picture we see a the gun exhibited at the Museum of Military History in Vienna. The inscriptions on the two named cap badges show that the they also depict the first two howitzers. The gun chassis of the cannon depicted on the BHL 17 badge differs from the first two. The later-produced specimens were mounted on a cannon base similar of the 24 cm heavy howitzer. This can be seen on this badge.