Gelatine explosive

Nitrogelatines. Fr term for Blasting Gelatin. Other terms include Gelatine Dynamite, Gelatine Explosible, Gelatine, Dynamite-Gelatine, etc Ref Daniel (1902), 325 523... 

Liquid nitroglycerine and gelatinous explosives made from it can exhibit two stable velocities of detonation, of approximately 2000 and 8000 m s 1 respectively. The phenomenon is complicated by the occurrence of air bubbles in such explosives and has not yet been completely explained. 

Semi-gelatine explosives (see p. 49) are manufactured and cartridged as powder explosives, although the presence of a thickened nitroglycerine base gives them properties which can approach those of gelatines. 

A recent cartridging machine is the Rollex, designed by the firm of Niepmann Sons. This operates on an entirely different principle in that the explosive is first rolled into a sheet and then portions of this sheet are cut off and automatically wrapped in paper. It can also be used for cartridging semi-gelatine explosives. 

Gelatine explosives are more costly in raw materials than the powder or semi-gelatine types, although this can to some extent be offset by greater ease, and therefore less expense, in manufacture. Their popularity throughout the world rests on a number of important advantages over other available explosives ... 

In designing a gelatine explosive, the same questions must first be answered as in the case of all other explosives, namely, the bulk strength required and the degree of resistance to water. Again the practical requirement is to provide these properties with the minimum proportion of nitroglycerine. 

Control of exudation depends mainly on the suitable choice of the nitrocellulose used. Some lack of uniformity in this product is certainly desirable. This offers no serious difficulty, although it is necessary to ensure a constant watch on manufacturing processes to see that quality is maintained. In other gelatine explosives, particularly those containing ammonium nitrate, exudation can be induced by slow chemical reaction. The addition of alkalis, for example, can liberate ammonia which in turn can react with nitrocellulose and cause it to lose its power of binding nitroglycerine. Such effects are accelerated at high temperatures and under wet conditions and it is usual practice to test all explosives under such adverse conditions before they are put on the market. 

In other explosives of a gelatine type some form of combustible is normally present. Most combustibles contain pores which hold air and they also assist mechanically in the trapping of air bubbles in the explosive. As a result, the lower the nitroglycerine content of a gelatine explosive, the easier it is to obtain adequate sensitiveness to commercial detonators. In the particularly difficult cases such as the higher strength gelignite... 

Gelatine explosives, initiated by commercial detonators, will normally fire at the low velocity of detonation initially, although this may well build up quite quickly into the high velocity. For some applications a high velocity of detonation is essential. This can be ensured by the addition of barium sulphate, or other material with density exceeding 2-8, in a fine form. Such additives have the property of ensuring rapid transition to the high velocity of detonation. This is, for example, of particular importance when the explosive is to be fired under a hydrostatic head, as in submarine work. 

Ammon gelignite. A nitroglycerine gelatine explosive containing ammonium nitrate as the main oxidising ingredient. 

Exudation. In nitroglycerine gelatine explosives, a liberation of nitroglycerine following breakdown of the gelatinous base. 

Gelignite. Originally a gelatine explosive containing potassium nitrate as oxidising material. Now often applied to any gelatine. 

Special gelatine. A gelatine explosive in which the main oxidising ingredient is ammonium nitrate. 

Detonation, "Space Catalysis Phenomenon in. See under "Detonation Velocity, Influence of Aging of Gelatin Explosives on ... 

Detonation Velocity, Influence of Ageing of Gelatin Explosives an. Ageing of dynamites and its influence on their sensitivity to detonation by influence was described in Vol 1 of Encycl, pp A110 to A112, but its influence on deton velocity was not discussed. Ageing of propellants was described on p A112... 

Gelatin explosive Nitro-glycol, Nitrocellulose, Potassium nitrate. Hour... 

Detonation Velocity, Influence of Ageing ia Gelatin Explosives (pp D666-L to D667-L) Detonation Velocity, Influence of Inert Components and Inert Additives (pp D667-R to D668-R)... 

GELATIN (Explosive). Amer name for Gelatin Dynamite Brit Gelatine Dynamite ... 

---