8-inch gun M1888

After the American entry into World War I, the United States needed a medium-range heavy artillery piece that could be transported easily. The quick solution was to take the existing 8-inch coast artillery guns from the fixed mountings or from storage and mount them on a drop bed rail car.[7] This was also done with a number of other weapons, including 10-inch (254 mm) guns, 12-inch (305 mm) guns, and 12-inch mortars. The 7-inch (178 mm) guns, 8-inch guns, and 12-inch mortars used a common carriage, with a depressed center and two 4-wheel or 6-wheel bogies. The bogies were interchangeable for standard gauge or (with 12-wheel bogies) 60 cm (23.6 in) gauge track. Outriggers and a rotating mount allowed all-around fire. This allowed the weapons to be used in coast defense against moving targets. A detailed description of the railway mounting is given in Railway Artillery, Vol. I by Lt. Col. H. W. Miller, USA.[8] A total of 96 8-inch guns (reportedly including spare Navy Marks 1 through 4 as well as M1888 guns) were considered available for railway mounting, and 47 were ordered to be mounted on railcars. Twenty-four were produced before the Armistice, and three of these had been shipped to France by that time.[2][9][10] These three and several 10-inch guns were the only US Army railway guns shipped to France in World War I, although five US Navy 14"/50 caliber railway guns (356 mm) saw action.

Since the railway weapons were on the M1918 carriage and railway car, some references erroneously refer to them as M1918 weapons.

All (or perhaps 37, references vary) of the 47 ordered were completed by the end of 1919 and the contract was cancelled at that point.[9] Unlike almost all other US railway weapons, the 8-inch guns were widely deployed in the inter-war years, and by 1942 were augmented by 32 ex-Navy Mark VI guns. Approximately twelve M1888 guns were deployed for the defense of Oahu, Hawaii. Others were stationed for the coastal defense of Manila, eventually one each on Corregidor and Bataan (dismounted from the railway carriage), with batteries at Newfoundland, Bermuda, Puget Sound, Chesapeake Bay, Delaware River, and Fort Hancock, New Jersey (near New York City).[11][12] Some 8-inch disappearing guns remained in fixed emplacements in the US until late in World War II, when they were scrapped as 16-inch guns and 6-inch guns on long-range mountings replaced all previous coast defense weapons.

An anecdotal account of the 8-inch M1888 railway guns in the Japanese invasion of the Philippines in 1941–42 states that eight guns (another account says seven guns) were shipped to Manila in late 1940, as part of the Inland Seas Defense Project. Initially, difficulties were encountered because the railway carriages were 36-inch (914 mm) gauge and the Philippines used a 42-inch (1,067 mm) gauge. In late December 1941 all eight guns were sent north in one train to oppose the Japanese landings at Lingayen Gulf, but six guns were damaged beyond repair by enemy air attack. The remaining two guns (possibly only one) were eventually shipped to Corregidor and Bataan by early March 1942, where they were mounted on improvised pedestal mounts. The account states that the one gun that information is available on fired only five proof rounds and sat idle for want of a crew until it was destroyed by air and/or artillery attack.[13][14] One reference states that the other gun was mounted near Bagac, Bataan.[15]