In November 1944, prior to the rave USMC reviews of Iwo Jima, the Fleet Marine Force had requested 54 mechanized flame throwers, nine for each of the Marine Corps Divisions On Iwo the tanks all landed D-day and went into action on D+2, sparingly at first. As the battle progressed, portable flame units sustained casualty rates up to 92%, leaving few troops trained to use the weapon. More and more calls came for the Mark-1s to the point that the Marines became dependent upon the tanks and would hold up their assault until a flame tank was available. Since each tank battalion had only four they were not assigned. Rather, they were "pooled" and would dispatch from their respective refueling locations as the battle progressed. One the 4th Division tanks had a 50 cal. machine gun coaxial to the flamethrower as well as concrete armor to counter placement of magnetic charges. Towards the end of the battle, 5th Marine tanks used between gallons per day.