Since aircraft of the period were not yet capable of carrying large diameter bombs the burden of delivering heavy firepower fell on the artillery.

The combatants scrambled to find anything that could fire a heavy shell and that meant emptying the fortresses and scouring the depots for guns held in reserve.

[3] The Mk XIX was a breech-loaded design with a Welin interrupted screw breech and used separate-loading, bagged charges and projectiles.

The carriage was a box trail with two large spoked steel wheels, a hydro-pneumatic recoil mechanism, and no gun shield.

[6] Before the United States entered World War II, the US Army declared the M1917 obsolete and the 99 complete guns were transferred to Brazil as part of a package of military aid in exchange for bases, with deliveries beginning in October 1940.

In 1941, the United States began supplying Brazil with replacement wheels and pneumatic tires to allow the guns to be towed at higher speeds.

[6] Prior to the outbreak of World War II, the Union Defence Force had planned to use these guns in the fortification of Durban, Cape Town and Saldanha Bay.