A US Army's M4 High Speed Tractor towing a 155 mm howitzer M2 "Long Tom"; France, July 1944.

Long Tom howitzer in tow

US soldiers load shell cassettes and clean the barrel of a captured German 20mm FlaK 38 anti-aircraft gun mounted on an Sd.Kfz.10/4 half-track tractor.

Captured anti-aircraft gun

M4A3 Sherman firing rockets from the mounted T34 Calliope rocket launcher in France, February/March 1945.

The T34 Calliope was a tank mounted multi-barrelled rocket launcher. It was also known as the steam organ due to its shape. It fired 4.5 inch rockets from 60 tubes.

Developed in 1943, it first saw active service in late 1944/early 1945. It had been planned to use them in both Normandy and during an offensive in the winter of 1944, but these plans were interrupted for various reasons.