fractures were detected, or when converting the M107 to an M110. In U.S. Army Service, the lowest level of retube was done at the Artillery Battalion's maintenance shop. Retubing could also be done by Ordnance Depot Support Units or at fixed depots such as Anniston Army Depot, Picatinny Arsenal, or the Miesau Army Depot in Germany. When retubing was done at the battalion level, the M578 Light Recovery Vehicle was used. The barrels could not be replaced using a single M578 due to weight and the need for precise placement of the barrel into the cradle to prevent damaging the barrel brass runners. Two cranes were used, one on either end of the barrel. Retubing could also be used to convert the 175 mm M107 to the 203 mm (8 inch) M110. This retubing was usually accomplished by the supporting U.S. Army Ordnance Company or a fixed depot as it requires an overhead electric rail winch and chassis modifications for the E2 barrel. A single M578 was used to lift the engine or transmission from the hull once a month to clean the engine and transmission compartment, which was covered by two aluminum deck plates. Combat history Vietnam War The M107's combat experience with the US military was almost entirely limited to the Vietnam War. The Vietnamese words Sấm Sét ("Lightning") and Vua Chiến Trường ("King of the Battlefield") were often painted on the guns to commemorate its sheer firepower. There, it proved its effectiveness by having one of the longest ranges of any mobile artillery-piece operated during that theater of combat in the Cold War, outranging the Soviet 130mm M46 heavy field-guns employed by the People's Army of Vietnam (PAVN). Maximum range with M437A2 or M437A1 projectile is approximately 32,800 m. This long-range advantage, along with its ability to rapidly move from its previous position, made it an effective weapon for destroying North Vietnamese Army and Viet Cong command-and-control sites, communications facilities and supply-columns, while evading counter-battery fire from its Soviet counterparts in service with North Vietnam. This was proven in 1968 at the Battle of Khe Sanh, where American forces came under a long and intense siege by North Vietnamese troops and were constantly bombarded by accompanying artillery fire. The M107 also had its disadvantages. It was noted for its relative inaccuracy at longer ranges. The gun was assigned to corps-level artillery units and a number of M107/M110