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Barlow Bomb

Army experts who had experimented with a score or more of aerial bombs in a search for the most effective form of explosive for use in war aeroplanes, were reported by The New York Times in September 1916 to have found a bomb of high explosive power which was said to excel in destructiveness any similar weapon known here or in Europe. Tests concluded in September 1916 were said to have proved so satisfactory that a report would be presented to the War Department advising the use of the bomb in the aviation service.

The inventor was Lester Pence Barlow [not Harlow Barlow, mentioned in United States, Congress, House - 1920 or F.E. Barlow, mentioned in The New York Times and The International Military Digest Annual], said to be an employe of the Frankfort Arsenal in Philadelphia. When he was a soldier of fortune in Pancho Villa's revolutionary army, Mr. Barlow began inventing bombs. After his discharge from the Navy in 1908, Mr. Barlow learned to fly. He joined the insurgent forces of Pancho Villa in Mexico in 1914 and there he first experimented with aerial bombs. The weapons were also being developed in France and Germany. Mr. Barlow's bombs, which he dropped on trains carrying Federal troops, were small and not very effective, but they launched him on his career as an inventor.

Barlow offered its exclusive use to the United States Government. Experts estimated that the bomb has a fatal destructive radius of at least 100 yards. With the use of minimum explosive charges, at elevations of 200 to 2,000 feet, the tests were said to be most satisfactory. The Barlow bomb was six feet in length, and five inches in diameter, and shaped like a torpedo. In addition to a charge of TNT, it contained a new and secret combination of gas. Subsequently, the term "Barlow Bomb" was applied to a mixture of liquid oxygen with a fuel.

One of the chief features of the bomb in which it differed radically from bombs which depend for bursting force on contact with the earth or other objects, is that it may be exploded in the air with full power. The Barlow bomb was supposed to explode on contact, and the explosion occurred 6 feet from the ground. The plan of the bomb was that the shell itself was demolished, and the shell being demolished and scattered by the explosive force was really the missle. This is said to enhance the destructive power to a much larger degree than any known form of contact bomb, as it may be exploded over the heads of troops and spread gases over a larger surface. By means of an electric timing device the operator will be able to regulate to a second the time of the explosion of the bomb.

These contemporaneous descriptions are of two different and unrelated bombs. The first is of a bomb in which the oxidizer is liquid oxygen, and the second is a bomb that can be detonated slightly above ground. Barlow held several patents covering the later type of bomb [assigned to the Marlin-Rockwell Corporation], but not relating to the former [McCloud et al. were granted patent #2,295,671 on 15 September 1942 for a liquid oxygen bomb]. Liquid oxygen in combination with a combustible absorbent agent had long been recognized as an efficient high explosive in the mining and similar industries and its use has been proposed for military purposes heretofore. There are, however, several obstacles in the convenient and safe use of liquid oxygen explosive and these are coupled with the inherent characteristic of liquid oxygen, namely; to rapidly evaporate when subjected to a temperature above its boiling point of -182 degrees centigrade and its tendency or ability of being easily detonated when incorporated with a combustible ingredient and brought into contact with a ferrous metal container. These obstacles present a serious problem in connection with the employment of liquid oxygen explosive as the explosive charge in a demolition bomb as they place limitations upon the use of the explosive, that is, limitations upon the time within which the bomb must be used after being charged with the liquid oxygen explosive and manner in handling, which are in direct conflict with military requirements.

John Mahlon Marlin, who opened his New Haven gun shop for business in 1870, manufactured the the oldest shoulder arm designs in the world still being produced. Originally introduced as Models 1891 and 1893 respectively, they still mirror the original designs. Marlin was the largest manufacturer of .22 rifles in America. Prior to WWI, Albert Rockwell formed the Rockwell Drake Corporation in Plainville, CT. In 1915 Rockwell combined several companies including Marlin Arms Corporation, Rockwell Drake and Standard Roller Bearing to form Marlin Rockwell Corporation (MRC). The non firearm portion of the business was manufacturing ball bearings and other non friction products. The company made machine guns for the US and its allies and became one of the largest machine gun producers in the world. The Marlin-Rockwell Corporation owned patent rights on a certain bomb, called the Barlow Bomb, a demolition bomb. There had been some tests made of it by the Ordnance Department experts, and at that time it was very highly regarded.

The US Army Ordnance Department came out the latter part of 1917 or early in 1918 and said that they proposed to conduct operations for the manufacture of aerial bombs, and rather desired the Marlin-Rockwell Corporation to take it up, the reason being that the Marlin-Rockwell Corporation had done a great deal of work for the Government up to that time. The Marlin-Rockwell Corporation's business with the Government had been entirely upon a fixed-price basis of contract, and they said that if they did take up this other work they wanted to do it through a subsidiary company, if, as the Government then stated, they wanted this work done on an agency basis. Negotiations were carried on - and the inception thereof was around the first of the year 1918 - which resulted in the incorporation of the Marlin-Rockwell Loading Co. about April 1, 1918, and the actual execution of a contract by the United States Government with the Marlin-Rockwell Loading Co. was made on May 22, 1918.

The plant was to be for the loading of aerial munitions with high explosives, and for assembling and packing the same, and to provide proper shipping facilities for water transportation of loaded aerial munitions, such aerial munitions to consist of bombs known as the Barlow heavy drop bombs, demolition bombs, Mark I, II, III, IV, and V, or such additional bombs or types of bombs as the agent's capacity and facilities may permit. Such plant was to have a daily capacity for the loading, assembling, packing, and shipping of approximately 500 Barlow heavy-drop bombs, 1,000 Mark I high-capacity drop bombs, 500 Mark II high-capacity drop bombs, 3.000 Mark III high-capacity drop bombs, together with estimated future requirements of 500 Mark IV high-capacity drop bombs, 250 Mark V high-capacity drop bombs (loaded with trinitrotoluol or other explosive) per day of 24 hours.

The Marlin-Rockwell Corporation was directed to manufacture that bomb so far as the shell itself was concerned, but not as to loading it with ingredients. They took the contract for the manufacture of shells, and that operation was carried on in the Philadelphia plant of the Marlin-Rockwell Corporation.

The Barlow bomb was destined never to cut any figure in our fighting in France. The production was slow, because of the necessity of constant experimentation to simplify a firing mechanism which was regarded as too complicated by the experts of the War Department. Finally, in June 1918, [some time from the 8th to the 15th of June 1918] when 9,000 of these bombs and 250 sets of release mechanisms had been produced, a cablegram came from the American Expeditionary Forces canceling the entire contract. The reason assigned for abandoning the bomb was that certain British bombs, the 25-lb Cooper bomb, was regarded as better, because of cheaper construction and the hazard of the missle functioning was regarded as less by the officers on the other side.

Barlow died on 05 September 1967. His New York Times obituary reports that "The patents on the Barlow bombs and torpedoes were kept secret during the war. They were made public in the mid-nineteen twenties." This is not quite accurate, since some of Barlow's patents were granted during the War, while others were granted in late 1919, about a year after the War's end. In the 1930s Barlow brought suit against the Government for infringement of six bomb patents [hed held at least nine such patents]. After Barlow's testimony in this matter, Senator Nye, handsomely announced: "Never in 15 years have I seen a Senate committee so thoroughly impressed." He was convinced that Mr. Barlow's bomb would give any nation an "incomparable advantage." In 1936 the US Court of Claims decided five of his six patent claims were valid, and in 1940 the Congress decided the Government owed him approximately half a million dollars.

In 1940 Lester Pence Barlow demonstrated a liquid oxygen-carbon explosive that he called "Glmite" [GLMite - Glenn L. Martin]. Barlow staged the demonstration at the Glenn L. Martin aircraft plant. Time Magazine reported that "The force of the explosion was felt 1,000 feet away. The new test will show Army and Navy men whether a bigger charge can, like Joshua's trumpet, make armies tremble and cities crumble."

The blasting or breaking of rock has become relatively less expensive as cheaper, and sometimes more effective, blasting agents have been developed. Black powders were used before the advent of nitroglycerine and, later, the less sensitive form of nitroglycerine, "dynamite," was introduced. In the 1950's, blasting agents composed of "prills" and oil, i.e., dehydrated ammonium nitrate (fertilizer) and oil, were developed and have become the cheapest and most commonly used blasting agent, particularly in open pit mining. The hazards of conventional explosives led to the use in the early 20th century of mixed liquid oxygen and a solid fuel, such as carbon black or sawdust. The heat loss in the hole in the time interval between filling and detonation, as well as other cryogenic problems, caused the abandonment of that development. In mixing with liquid oxygen ambient temperature fuel, fuel oil or powdered coal in the hole, the liquid oxygen (hereinafter referred to as "LOX") boiled off in cooling the fuel alone will be roughly 1.5 times the LOX required for the explosive, so that cooling and mixing in the hole is economically unattractive.

In L.P. Barlow's Patent No. 2,704,515 issued March 22, 1955, he disclosed the use of such LOX explosives wherein a blast hole is drilled, the hole partially filled with the mixture of combustible material and a liquified inert gas having a boiling point preferably no higher than that of oxygen, such as nitrogen, the nitrogen permitted to vaporize with the accompanying freezing of the ground around the blast hole and liquid oxygen subsequently introduced into the blast hole. On May 22, 1962 L.P. Barlow was granted US Patent 3,035,519 for one such method.

Marlin Rockwell Corporation was purchased in 1964 by TRW Inc.

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