On the Cassino front the Allied forces had by 22 February 1944 in addition to sixty 155-mm. Long Toms, twelve 240-mm. howitzers, which had a range slightly less than the Long Tom but a projectile more than three times as powerful. The 240-mm. howitzer and the 8-inch gun were the heaviest mobile U.S. artillery weapons.
The heavy howitzers were ideal for the main Fifth Army front, which was "howitzer country," because they could deliver a heavy weight of explosive on the reverse slopes of mountains. In operations in the high Apennines after the capture of Rome, Maj. Gen. Alfred M. Gruenther considered the 240-mm. howitzer the most generally satisfactory artillery weapon Fifth Army had.
Caption: 240-MM. HOWITZER IN THE SAN VITTORE AREA
Image on page 23 of Mayo, Lida. THE ORDNANCE DEPARTMENT: ON BEACHHEAD AND BATTLEFRONT. Washington, DC: CENTER OF MILITARY HISTORY UNITED STATES ARMY, 1968. Accessed March 21, 2018. https://history.army.mil/books/wwii/Beachhd_Btlefrnt/index.html#contents.