Dr. John Darrell Sherwood is a historian with the Naval History & Heritage Command and the author of four books on the Vietnam War.
April 26, 2010 - The iconic river craft of the Vietnam War was unquestionably the PBR—a boat made famous by the film Apocalypse Now (1979). The Navy employed the PBR (Patrol Boat River) to patrol the rivers and canals of South Vietnam and to search river traffic for insurgents, arms, and ammunition.
The PBR’s life began at Hatteras Yacht Company in North Carolina in 1965. Responding to a request for a small patrol boat, Hatteras proposed a 28-foot fiberglass hull powered by water-jet pumps. As opposed to propellers, water pumps would allow the new boat to operate in extremely shallow water. Enthusiastic about the proposal, the Bureau of Ships asked for a prototype that could not only achieve speeds of 25 to 30 knots and draw just nine inches of water, but also accommodate a crew of four along with extensive equipment and weaponry, including a twin .50-caliber machine gun in an armored turret forward and a .30-caliber gun (later replaced by a .50-caliber) aft.
Impressed with the prototype, the Navy requested 120 such boats in less than 6 months. United Boatbuilders of Washington State ultimately won the contract with the lowest bid. The eventual Mark-I design incorporated a 31-foot fiberglass cruiser hull along with a completely new, Navy-designed superstructure. Twin General Motors 216 horsepower diesel engines powered the boat’s water propulsion system. Fully loaded, the boat weighed 14,600 pounds and could reach speeds of up to 25.7 knots. The original boats cost just $75,000 each.
The beauty of the PBR design was its innovative application of commercial technology to a military role. The boat’s Styrofoam-filled fiberglass hull, for example, did not rust or corrode and was strong enough to withstand beaching. It was also easy to repair. Most remarkably, shaped warheads often did not trigger on it but rather went right through the boat without exploding because there was no solid target to detonate. The PBR’s water jet propulsion system allowed the boat to travel on virtually any waterway in the Mekong Delta and perform maneuvers impossible for traditional screw-driven boats. A PBR could run over a sandbar or beach itself on dry land and could stop or turn 180 degrees in its own length.
The PBR, however, was not immune to problems. Fully loaded, the Mark I PBR ultimately drew 22.5 inches of water—far more than the nine inches planners had originally requested. The Mark I boats deployed to Vietnam also never attained the trial speed of 25 knots. At the heart of the PBR’s speed shortfalls were the Jacuzzi pumps, which greatly reduced the efficiency of the GM engines—with screws instead of water jets the boat probably would have achieved speeds in excess of 40 knots.
Despite these issues, the PBR performed better than expected. Developed in urgency, the PBR proved a fierce warrior in combat, useful not only for river patrols but for interdicting Viet Cong river crossings and special operations. The most decorated Sailor in Navy history, Boatswain’s Mate First Class James Elliott Williams served on PBRs and the Navy’s River Patrol Force (Task Force 116) received Presidential Unit Citation for its role in interdicting enemy forces moving into the upper Mekong Delta from Cambodia in 1969.
Posts
No comments:
Post a Comment