The old MK 9 guns on the town green
Here we have the two U.S. Navy Mark IX guns installed in the city park in Pass Christian, Mississippi. The US Mk 9 4-inch gun (102mm) /50-caliber was one of those things that was great when designed in 1909 but within just a few years was obsolete.
A naval rifle with a Smith-Asbury type side swing breech mechanism with a Welin block, it was chrome lined, an interesting feat at the time to help prevent coppering and steel choke issues. Designed around 1910, they were popular with small warships of the US Navy for about twenty years, being installed on the Wickes and Clemson class destroyers (almost three hundred vessels) as well as several 1920s era US submarines as deck guns. They weighed about 5400-pounds and are 17-feet long overall. A well-trained 9-man crew could ram, lay, and fire as many as 8 aimed shells per minute at a target nearly 15,000 yards away. When you take into account that these shells were 60+ pounds, you see that as a feat.
By WWII, these guns were being removed from the fleet at a very fast clip, although one example did fire the first American shot of the Pacific war. Used to arm merchant ships and given away as military aid, most of these old remaining Mark 9s were scrapped in the 1950s, and a few, such as these in PC, are all that are left.
These are Mk 9 Mod 5 guns made in 1919 at Bridgeport, according to their breeches. The first gun is numbered No.674 while the second’s barrel number is unreadable. Any information as to which hull they came from would be interesting.