Armstrong gun

An Armstrong gun was a type of rifled breech-loading field and heavy artillery piece designed by Sir William Armstrong. It was first manufactured in England starting in 1855 by the Elswick Ordnance Company and the Royal Arsenal at Woolwich.

The Armstrong gun employed a distinctive built-up gun construction method. The core of the gun consisted of a wrought iron (and later, mild steel) inner tube, which was reinforced by a series of wrought-iron coils shrunk over it. This design kept the inner tube under constant compression, increasing its strength and resistance to internal pressure generated during firing.