[2] Later models of the launcher also had flame deflectors to help prevent rocket exhaust from entering the engine compartment.

[3] Although Calliopes were originally manufactured before D-Day and were envisioned for bunker-busting duties on the beaches, the proposal was dropped due to the tank's high center of gravity which made its transportation unsteady.

Thirty M4s of the 743rd Tank Battalion had the T34 launchers installed to assist a planned push by the 30th Infantry Division in December 1944.

The German Ardennes offensive stopped this plan, and the launchers were subsequently removed and not reinstalled on tanks until February 1945 with General Patton's army.

In March 1945, when Patton's army was pushing through the Saarland in western Germany, the launchers did manage to see some usage in armored divisions.