Coehorn

A Coehorn /ˈkoʊhɔːrn/ (also spelled cohorn) is a lightweight mortar originally designed by Dutch military engineer Menno van Coehoorn.

Van Coehoorn came to prominence during the 1688–1697 Nine Years War, whose tactics have been summarised by historian John Childs: "The majority of infantrymen never fired their muskets in anger; ... armies were consciously geared towards the dominant forms of warfare: manoeuvre and the siege.

The low muzzle velocity meant the shell's high, arching flight could be easily observed from ground level, but this was not necessarily a problem, since the gun's original purpose was to provide cover rather than inflict casualties.

At the siege of Vicksburg in 1863, the Union forces had so little artillery that "wooden [coehorns] were made by taking logs of the toughest wood that could be found, boring them out for six or twelve pound shells and binding them with strong iron bands".

Range required adjustment in the size of the powder charge; the 24-pounder version could theoretically fire a 17 lb shell (5.82 in) up to 1,200 yards (1,100 metres), but this was optimistic.