Books by War Department

The Bailey Bridge is a type of portable, pre-fabricated, truss bridge. It was developed by the British during World War II and saw extensive use by both British and American military engineering units. It had the advantages of requiring no special tools or heavy equipment to construct. The wood and steel structural elements were small and light enough to be carried in trucks, and lifted without requiring the use of a crane. The bridges were strong enough to carry any military load, including tanks. Stories of Bailey Bridges being built and erected during the Second World War are legendary. By the end of the war, the US Fifth Army and British 8th Army had built over 3,000 in Sicily and Italy alone. Today, they continue to be vastly used in civil engineering construction projects and to provide temporary crossings for people and vehicles. Created in 1943, this technical manual reveals a great deal about the Bailey Bridge's design and capabilities. Intended as a manual for those charged with bridge construction, it also details many aspects of bridge maintenance and traffic control. Originally labeled restricted, this manual was declassified long ago and is here reprinted in book form. Care has been taken to preserve the integrity of the text.

A modification of the 2-ton "deuce", the DUKW amphibious truck was designed in 1942 by a team that included a British sailor, an American yacht builder and an MIT engineer. Powered by a GMC Straight-6, 270 cubic inch engine, the DUKW's six drive wheels allowed it to move up to 50 mph on the road and at roughly 6 mph in water. It was the first vehicle ever designed to allow tire pressure to be adjusted from inside the cab, allowing it to operate easily and efficiently on sand, rock, gravel and paved roads. The vehicle lacked armor, but one in every four produced came equipped with a machine gun ring mount. Overall, the DUKW weighed 6.5 short tons empty and could carry 2.5 short tons or twelve soldiers. The DUKW's career in combat was unique, being used to ferry supplies and men from ship to shore, and operating in flooded environments. It was used in landings in the Pacific and European Theaters, including at D-Day, and many were also used during the Korean War at Inchon. Incidentally, the term "DUKW" is not a military term, but rather an acronym coined by General Motors. "D" stood for the year it was designed, 1942. "U" stood for "Utility", "K" for front wheel drive, and "W" for two powered rear axles. Over 21,000 DUKWs were built during WWII. Some remain in use today as amphibious tour buses. Originally created in 1945, this War Department technical manual contains a full description of the DUKW and shows how to operate and maintain it. Originally restricted, this manual was declassified long ago and is here reprinted in book form. Care has been taken to preserve the integrity of the text.

Designed by Swedish cryptographer Boris Hagelin, the M-209 Converter was a portable, mechanical cipher machine. Used extensively during WWII and the Korean conflict by both the Army Signal Corps and the U.S. Navy (which designated it the CSP-1500), Hagelin's device allowed a rapid and secure means of communication. The lunchbox-sized machine was so simple that little training was required to use it, yet its cipher scheme proved very difficult - but not impossible - for the Germans to crack. The M-209's elegant design uses six adjustable key wheelsor rotors to produce a reciprocal substitution - also known as a Beaufort cipher. The effect was that of sliding a normal alphabet sequence against the same sequence reversed, with a high degree of irregularity in the shifting process brought about by a train of gears. In the train of gears, the number of teeth on the driving number was also varied by the use of keying elements. Prepared by the War Department for the Signal Corps and other users, this M-209 technical manual describes the operation and care of this fascinating device. Originally printed in 1942 and classified restricted, it was declassified long ago and is here available in book form.

The 155-mm Howitzer M1 was first produced in 1942 as a medium artillery piece. It saw service with the US Army during World War II, the Korean War, and the Vietnam War, before being replaced by the M198 Howitzer. The gun was used by the armed forces of many nations, and in some countries, it still remains in service. The 155-mm Howitzer was developed as an afterthought. A new carriage was under development for much of the 1930s for the existing World War I era M1918 until 1939 when it was realized that it did not seem logical to put a new carriage underneath an obsolete howitzer. Consequently, development began anew with a carriage designed to be used for the 155-mm Howitzer. This was completed by May 15th, 1941 when the Howitzer M1 on the Carriage M1 was standardized. The howitzer itself differed from the older model by a lengthened barrel of twenty calibers and a new breech mechanism. Uniquely, it was the sole 'slow-cone' interrupted screw mechanism to enter service after 1920. This meant that two separate movements were necessary to open the breech, versus the single movement of the 'steep cone' mechanism that simultaneously rotated and withdrew the breech. Created in 1943, this technical manual reveals a great deal about the 155-mm Howitzer M1's design and capabilities. Intended as a manual for those charged with operation and maintenance, it details many aspects of its assembly, ammunition, and accessories. Originally labeled restricted, this manual was declassified long ago and is here reprinted in book form. Care has been taken to preserve the integrity of the text.

The Light Tank M24 was an American tank used during the later part of World War II and in postwar conflicts including the Korean War and, with the French, in the War in Algeria and the First Indochina War. In British service it was given the service name Chaffee, after the United States Army General Adna R. Chaffee, Jr., who helped develop the use of tanks in the United States armed forces. In April 1943, the Ordnance Corps, together with Cadillac division of General Motors, started work on the new project, designated Light Tank T24. Every effort was made to keep the weight of the vehicle under twenty tons. The armor was kept light, with the glacis plate only twenty five mm thick (but sloped at sixty degrees from the vertical). A new lightweight 75 mm gun was developed, a derivative of the gun used in the B-25H Mitchell bomber. The gun had the same ballistics as the M3, but used a thinly walled barrel and different recoil mechanism. The design also featured wider (sixteen inch) tracks and torsion bar suspension. It had a relatively low silhouette and a three-man turret. On October 15, 1943 the first pilot vehicle was delivered and production began in 1944 under the designation Light Tank M24. By the time production was stopped in August 1945, 4,731 M24s had left the assembly lines. The M41 155-mm Howitzer Motor Carriage was based on the M24 Chaffee Light Tank fitted with an M1 155-mm Howitzer. In addition to the Howitzer, the M41 carried twenty two rounds of 155-mm ammunition. Also known as the Gorilla, the M41 eventually saw action in Korea. Created in 1947, this technical manual reveals a great deal about both the Chaffee's and M41's design and capabilities. Intended as a manual for those charged with maintenance, it details many aspects of the Chaffee's track and suspension, hull, turret and other systems. Originally labeled restricted, this manual was declassified long ago and is here reprinted in book form. Care has been taken to preserve the integrity of the text.