Marines from Bridge Company, 7th Engineer Support Battalion, Combat Logistics Regiment 1, 1st Marine Logistics Group toss lines across a body of water to tow in two Mark III Improved Ribbon Bridges. The battalion trained in tandem with Marines from 6th ESB out of Battle Creek, Mich., aboard Marine Corps Base Camp Pendleton, Dec. 12, 2015. The IRB is a more improved version of the original and is used to move personnel and tactical vehicles over non-passable waterways. - Marines from Bridge Company, 7th Engineer Support Battalion, Combat Logistics Regiment 1, 1st Marine Logistics Group toss lines across a body of water to tow in two Mark III Improved Ribbon Bridges. The battalion trained in tandem with Marines from 6th ESB out of Battle Creek, Mich., aboard Marine Corps Base Camp Pendleton, Dec. 12, 2015. The IRB is a more improved version of the original and is used to move personnel and tactical vehicles over non-passable waterways.