The 28 cm Kanone 5 (E) (nicknamed "Schlanke Bertha" or 'Slender Bertha' by its German crews and "Anzio Annie" by American troops who faced it) was a large railway gun produced by Krupp during World War II.
The K5 was capable of firing its 28 centimeter shells at a maximum range of up to 64 kilometers. Due to the nature of the weapon, the gun had a traverse range of only 2˚ and an elevation range of +50˚. In order to turn the weapon to a greater degree, special curved track sections or even an entire turntable had to be constructed at pre-determined locations well ahead of any combat operations. As the locations from which the gun was used were chosen ahead of time, oftentimes they possessed tunnels or shelters for storing the gun in between fire missions.
The gun itself had a total weight of 197,766 kilograms and overall length of 32 meters. 3 meters wide and 3.96 meters tall, the K5 gun was operated on by a crew of 42 artillery officers and enlisted men. The gun itself rested on a gondola atop two six-axle, twelve-wheel bogies, one set at either end of the gun.
Each shell fired by the gun weighed about 255.5 kilograms and exited the barrel at a muzzle velocity of close to 1,128 meters per second. During combat operations, all ammunition and cordite powder bags were stored separately for the purpose of safety. Batteries of K5 guns were organized into two guns per battery, with three locomotives assigned to the battery, along with accompanying security and miscellaneous personnel. Two types of locomotive were allocated to transport the K5, one powered by diesel and the other powered by steam. Though steam power was preferred initially for being cheaper and more available, the identifiable white smoke produced was a clear identifier to Allied aircraft of a potential target.
- K5 Tiefzug 7 mm: K5 Rail gun with the rifling grooves reduced to 7 mm deep from 10 mm to prevent cracking
- K5Vz: Experiment to allow the gun to fire rocket-assisted shells
- K5 Glatt: Experiment to rebore the gun to 310 mm to fire Peenemünder Pfeilgeschoss shells
HistoryThe K5 was developed in the early 1930s to correct some of the faults in earlier World War I-era rail guns. Guns like the famous 'Paris gun' for example had incredible range, yet had very little accuracy. By 1934, Krupp had developed a prototype weapon with a bore of 120 mm. This weapon was designed to take advantage of the good German railway system already in place, allowing for it to be able to be transported relatively easily. Eight guns had been produced by the Invasion of France, and following the campaign, were installed into the Atlantic Wall. From there, they fired upon British shipping, forcing merchant ships to operate only at night, and into the operating area of German U-boats.
Famously, two K5s were sent to Italy in 1944 to help repel the American landings at Anzio. These two were nicknamed "Leopold" and "Robert" by their crews and "Anzio Annie" and "Anzio Express" by Allied soldiers. The two guns were captured on June 7, 1944, and though one was damaged by its crew, the other was deemed in good shape and shipped back to the United States at Aberdeen. In all, some 25 examples had been built during World War II.