The Fd. 5.5 Gun is a light artillery piece in service with the Imperial Navy, 10 cm in caliber. The original Fd. 5.5 Gun was introduced in 1900, the current models being the Modell 18 and the Modell 26, the latter in a dual-purpose mount enabling it to act both as an anti-surface and an anti-aircraft gun.
The Imperial Army uses a howitzer of a similar caliber, the Fd. 5.5 Howitzer. Neither gun uses similar ammunition. Modell 11 and Modell 18 guns use the same ammunition, while Modell 26 guns use a new type of shell.
The Modell 11 is the successor to the original Modell 1900. As a quick-loading gun, it fired fixed 5.5 Faden (or 10 cm) shells of 17.5 kg over a distance of 13 km at 30 degrees of elevation - the gun can be elevated from -10 degrees to +35 degrees.
Currently, old Modell 11 guns and mounts are used up on auxiliary vessels and in coastal defenses.
Modell 18
The Modell 18 was basically the same gun as the Modell 11, but in a new mount, which allowed the gun to be elevated to +75 degrees, technically a dual-purpose mount, but not yet. The Modell 18 is also used on submarines as a deck gun.
Modell 26
The Modell 26 is a 3 ton heavy (barrel and breech) gun firing a 13 kg shell over a distance of 14 km or 11 km upwards effectively (the shells can reach ranges up to 20 km and 13 km respectively). The gun has a high muzzle velocity, shortening the service life of the 6.8 meter long barrel to between 350 and 400 effective full charges.
Mounts
The Fd. 5.5 Gun is available in single and double mounts as secondary artillery for larger cruisers and battleships, as single-mount main artillery for destroyers and torpedo boats and in casemates for fortresses.