The heaviest piece of artillery available to the American Army, the 240mm was a titanic gun capable of levelling any fortification to dust. It was also capable of engaging naval warships with great effectiveness. Soviet combat engineers learned to fear the M1, for its batteries could reduce even the heaviest fortifications and deny them of this advantage. Some were simply left in the Pacific's islands at the end of the war due to the costs of moving them, and were stolen by Oceanykan pirates.