By Mack Barham, M.D.
With Notes on an Expedient Mount for the Japanese Type 92 Aircraft Lewis Gun
The 1933 film classic “King Kong” ends with the philosophical observation by Denham that “it was beauty killed the beast.” Close observation of the final scenes of the movie indicates that Lewis Guns firing from Scarff rings were intimately involved with Kong’s untimely fall from grace. Within a year, both the Japanese Army and navy independently adopted Lewis Guns into their arsenals. Mere coincidence? Probably so, as the date of adoption of the Lewis by the Japanese was actually 1932, a year before the movie “King Kong” was released. At least after the movie came out the Japanese were sure that their choice had substantial killing power!
Prior to WWI, in 1907, the Vickers and Armstrong Companies entered into an agreement with the powerful and influential Mitsui family in Japan to form Nippon Seikosho, or Japan Steel. It was created to produce ordinance in Japan. When Japan embarked on a program to develop a military air arm, they again relied heavily on their allies from WWI, the British. The Japanese Navy sent out competitive bids for aeronautical engineers to design a carrier-based fighter. Early on, the island nation of Japan envisioned a major role in their military future for a carrier based air arm. Herbert Smith, of the famous Sopwith firm in Great Britain, went to Japan in 1921 and led the development of the Type 10 Naval fighter. Carrier takeoffs and landings were completed by 1923.
Since the combination of forward mounted Vickers guns, firing through the propeller, combined with Lewis guns in flexible mounts, were battle proven and had served effectively and reliably in the First World War, both these guns were adopted by the nascent Japanese Naval Airforce and became the standard armament of a generation of Japanese Naval warplanes. The familiarity of the English engineers who were overseeing the project with the Lewis and Vickers was critical to their adoption. The Lewis clone was adopted as the Type 91 Navy Aircraft Machine Gun, Flexible (Kuni shiki kaigun senkai kikanju.) In 1932 production of the Lewis began in Japan. Parts from these guns will interchange with British Lewis Guns.
Some guns were issued with a barrel jacket, others without. Tripods were provided for the guns issued for shore or deck use that allowed elevation of 85 degree and depression of 80 degree. Lewis guns were frequently used on small ships in an anti-aircraft role. Some were issued with shoulder stocks while others were issued with spade grips. Many were used on flexible mounts in both carrier and land based aircraft.
Most of the aircraft guns were mounted on Scarff Rings (invented by Frederick W. Scarff) or on flexible mounts in turrets or ports. In some of these guns the trigger guard was removed, apparently to make them easier to operate while wearing gloves. The Scarff Rings and gun ports were open to the atmosphere, and could get quite cold. Conventional and wind vane sights were used on these guns, bit in air to air combat most gunners relied on the paths of the tracers that were loaded every fifth round. Most aircraft Type 92s were issued with 96 round drums, but the 47 round drums would also function.
The caliber was adopted unchanged – .303 British. By the time WWII started, Japan had 3 different 7.7mm rounds. This must have created a major headache for supply officers. The Army Type 92 HMG initially fired 7.7mm ‘semi-rimless’ Shiki 92 ammunition. This round was supplanted by the 7.7mm rimless Shiki 99 seven years later. Neither of these rounds would work in the navy Type 92 Lewis clones, because lacking rims, they would not stay in the drum magazines designed for the wide rimmed .303 British round.
Why Type 92? And why are there other Type 92s? In 1926 the reign of Emperior Hirohito began. His reign was known as the Showa Era, meaning ironically “enlightened peace”! A new system of ordinance model designation was adopted in Japan coincident with the start of the Showa Era. Weapon models were designated by the last two numbers of the year of adoption. The year in question was not the year on the Gregorian calendar, rather it was the year designated by the Japanese calendar. The Lewis was adopted by the Navy in the Japanese year 2592 (our 1932), hence it became the Type 92.
The Japanese Army and Navy were independent in their arms acquisition. Consequently, when weapons were adopted in the same year by both services, terminology became redundant and somewhat confusing. When the Army adopted a new heavy ground machine gun in 2592, it also was designated a Type 92. This “other” Japanese Type 92 machine gun (Shuki Kikanju), was an improved Taisho 3rd year heavy machine gun (3 Nen Shiki Kikanju, 1914.) designed by Lt. General Kijiro Nambu. It was a gas operated, air cooled Hotchkiss design. The only deviation from the Hotchkiss system was a Lewis style ejection system. Hence, some aspects of Issac Newton Lewis’ design are found in all Japanese Type 92s.
While not a common gun in collections in this country, original mounts are even less common. If you are like most people and lack a vintage Japanese aircraft in which to mount your Type 92, the following is a relatively easy and inexpensive way to create an expedient mount from which to shoot, assuming that the Type 92 in questions is equipped with the circular swivel and yolk mount like the one in the pictures in this article. An MG 34 Anti aircraft tripod (available from time to time from Sarco and IMA) can be used to mount the Jap Type 92 Lewis. All that is required is a simple adapter that can be assembled quickly from readily available components.
You will need a 4.25” x 0.43” bolt with a nut and two 1.7” washers with 0.5” holes (see drawing). Drill out a 0.45” hole in two pieces of bar stock 0.768” long and 0.89” in diameter to create bushings that will fit on the bolt. This apparatus is then bolted on to the ring mount on the Type 92 to function as a trunnion. After removing the MG 34 mounting bracket, the adapter will fit snugly into the MG 34 mount where it is secured by the clamps on the tripod head. You are now ready to rock and roll! The Type 92 pictured in this article was manufactured at the Nagoya Arsenal. Others were produced at the Tokyo Arsenal. It shoots at a cyclic rate of 600 rounds per minute.
If imitation is the sincerest form of flattery, then the Japanese were obviously impressed with Col. Lewis’ invention. It seems ironic that when WWII erupted, machine guns designed by an American and Introduced to the Japanese by a Briton, were used by Japan against Allied forces. This was transpiring some 30 years after the same weapon was rejected by General Croizer and the American Army Ordinance Board as being unsuitable for combat use! Readers interested in an in depth discussion of the checkered history of arms acquisition by the American Military are directed to the fascinating (and often frightening) book Misfire The History of How America’s Small Arms Have Failed Our Military by: William H. Hallahn.
Further Reading and References:
Military Aircraft 1914 – 1980,
The Military Press,
New York, NY 1988
Chinn, George M.,
The Machine Gun, Vol 1 1,
Ann Arbor, MI
Goldsmith, Dolf L.
The Grand old Lady of No Man’s Land – The Vickers Machine Guns,
Collector Grade Publications,
Cobourg, Ontario, Canada 1994
Hallahan, William H.,
Misfire, The History of how America’s Small Arms Have Failed Our Military,
Charles Schribner’s Sons,
New York, NY 1994
Aircraft in Warfare The Dawn
of the Fourth Arm,
Constable & Co.,
London, England, 1916
Japanese Infantry Weapons
of World War II,
Hippocren Books, Inc.,
New York, NY, 1976
Nakata, Tadao and Nelson, Thomas B., Imperial Japanese Army and Navy Uniforms and Equipment,
Chesa Ltd., Hong Kong, 1987
Vickers, A History,
Weidenfeld and Nicolson,
London, England, 1962
Machine Guns, a Pictoral, Tactical and Practical History,
Boulder, CO, 1989
Truby, J. David,
The Lewis Gun,
Boulder, CO., 1988
|This article first appeared in Small Arms Review V2N12 (September 1999)|
and was posted online on February 5, 2016