This film profiles Dr. Otto Reitlinger and the Otto Fuel II monopropellant he developed, which is used to drive torpedoes and other weapon systems. The film touches on the safety issues affiliated with the fuel and potential ill effects from exposure to the product. It features extensive footage inside the Naval Propellants Plant of the Bureau of Naval Weapons, located at Indian Head, Maryland.

Otto fuel II, or just ‘Otto fuel,’ was a mixture of propylene glycol dinitrate (the explosive fuel), dibutyl sebacate (a desensitizing additive) and 2-nitrodiphenylamine (a stabilizer). Mixed together, they form a relatively stable (if toxic) oily substance. It does not throw off fumes, being oily (sebacate) and in liquid form is resistant to fire. However, if the fuel is vaporized, the stabilizer and desensitizer will separate from the propellant, which is then unstable enough to decompose violently, releasing energy. One of its reaction products is hydrogen cyanide, which is horribly toxic; as a result, torpedos which accidentally ‘run hot’ inside submarines will release highly toxic fumes into the boat which must be contained and vented.

At 2:43, various weapons that use the Otto Fuel II are shown including submarine dropped torpedoes at 3:00.

At 3:10 a rocket motor is tested at the Naval Propellant Lab. At 4:30, torpedo fuel tanks are shock tested to show the stability of Otto Fuel, and at 4:51 it proves difficult to ignite when contacted with open flames. At 8:00, Otto Fuel is loaded into a steel pipe and subjected to heat, effectively making a bomb. To make sure that this does not occur in proper working conditions all containers must have safety release valves.At 9:00 workers are shown being careless — and smoking around the fuel.

At 9:14 the Naval Hospital at Bethesda, Maryland is shown, where Otto Fuel is tested for human health effects. The Naval Medical Research Institute is shown where rabbits are tested for exposure to toxic levels of fuel. At 9:47, personnel are shown wearing breathing apparatus to clean areas contaminated with fuel. At 11:00, a man takes a shower after coming into contact with Otto Fuel. At 13:15, proper handling of Otto Fuel is shown at a transfer station, with polyester liners shown inside fuel drums, and all equipped with safety release valves. At 15:30, an Otto Fuel II fire is fought with water, which is quite in contrast to diesel fuel or gasoline.

This distinct-smelling, reddish-orange, oily liquid is a mixture of three synthetic substances: propylene glycol dinitrate (the major component), 2-nitrodiphenylamine, and dibutyl sebacate. It does not need exposure to any oxidant to ignite and release energy, as its three components will react among themselves whenever vaporised and heated. Needing no oxidants and being a stable substance makes Otto Fuel II ideal for use in the constrained environment of a submarine. Although the fuel can be made to explode, this requires extreme conditions (such that it can be regarded as practically stable). The vapour pressure of the fuel is low (i.e., it is not volatile), minimising toxic hazards. Finally, the fuel’s energy density far surpasses the capacity of the electric battery used in other torpedoes, maximising range.

Named after its inventor, Otto Reitlinger, Otto Fuel II consists of the nitrated ester explosive propellant propylene glycol dinitrate (PGDN), to which a desensitizer (dibutyl sebacate) and a stabilizer (2-nitrodiphenylamine) have been added. The chief component, propylene glycol dinitrate, accounts for approximately 76% of the mixture, while dibutyl sebacate and 2-nitrodiphenylamine account for approximately 22.5% and 1.5% (by weight), respectively.

The principal current use of propylene glycol dinitrate is as a propellant in Otto Fuel II. Nitrates of polyhydric alcohols such as this have been used in medicine for the treatment of angina pectoris, and as explosives since the mid-nineteenth century.

In addition to its use by the United States Navy as a stabilizer in the manufacture of Otto Fuel II, 2-nitrodiphenylamine is employed for similar purposes by the United States Army in the manufacture of double base solid propellants. It also has civilian applications as a solvent dye.

Dibutyl sebacate is a desensitizer in Otto Fuel II. However, its major use is as a plasticizer in production of plastics, namely cellulose acetate butyrate, cellulose acetate propionate, polyvinyl butyral, polystyrene, and many synthetic rubbers. It can be used for plastics in use in the food packaging industry. It is also used as a lubricating ingredient in shaving lotions, and a flavoring additive in non-alcoholic beverages, ice cream, ices, candy, and baked goods.

The Naval Surface Warfare Center, Indian Head Division (NSWC) has the longest running history of any Naval ordnance facility in the United States. The Navy has conducted munitions-related activities on the property continuously since 1890. These activities have evolved from the historical testing of guns, gunpowder, and other explosives to current activities in the manufacture and testing of propellants and propulsion systems for missiles and other weapons. Established in 1890 as the Naval Proving Ground, it became the Naval Powder Factory in 1932, the Naval Propellant Plant in 1958, the Naval Ordnance Station in 1966, and the Indian Head Division, Naval Surface Warfare Center in 1992. The changes in name have accompanied changes in the mission of the station as it transitions from a proving ground/production facility, to an engineering and technical center.

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This film is part of the Periscope Film LLC archive, one of the largest historic military, transportation, and aviation stock footage collections in the USA. Entirely film backed, this material is available for licensing in 24p HD, 2k and 4k. For more information visit http://www.PeriscopeFilm.com