V Amphibious Corps (VAC) wanted mechanized flamethrowing capabilities for the Marianas operations. VAC had ordered and received two shipments of Canadian Ronson F.U.L. Mk IV flamethrowers (30 flamethrowers in total) to field modify tanks. With a war to wage field modification was much quicker than going through official military procurement channels. The 117th CB was assigned to the upcoming Saipan operation. Col Unmacht worked out an arrangement to not only keep the 117th Seabees he had, but get more. Augmented by the additional Seabees, the group worked sun up to sundown and, with Seabee Can-do twenty-four M3s were modified to start the campaign. The very first, made by the 43rd Co, was christened "Hells Afire". The installation configuration of the flamethrower components limited the turret's traverse to 180°. As Satans were produced Colonel Unmacht had the Seabees conduct a comprehensive series of 40-hour classes on flame tank operation with first and second eschelon maintenance. First, for officers and enlisted of the Marine Corps and then later for the Army. The Satans had a range of and were the first tanks to have the main armament swapped for flame throwers. They were divided between the 2nd and 4th Marine Divisions for Siapan and Tinian with Tinian being more favorable to their use.