EXPLOSIVES.
Working Knowledge.
Handling. In moving cases containing explosives great care should be taken that they are not placed on anything or in such a position that they might topple over or be knocked over, or placed in such a position that other objects might fall on them. Men who are entrusted with the handling of these materials should be most reliable and careful.
The Thawing of Frozen Explosives. Some explosives freeze in a temperature considerably above freezing point, and it is necessary that they be thawed before using. The two recognized methods of thawing frozen explosives are as follows:
1. Place in a steam heated room, but not on the steam pipes. It is desirable that the room have an even temperature.
2. By the use of a double heater; the outer vessel to contain water at a temperature of 125 deg. F., or not hotter than can be borne by the hand; the inner vessel contains the explosive, care being taken that there is no fire in the vicinity.
A Few Causes of Accidents with Dynamite. The following are a few of the causes of accidents with explosives, as taken from statistical information compiled by the Ontario Bureau of Mines, and circulated for the purpose of preventing accidents:—
Dynamite.
1. Forcing primer into hole which is too small for it.
2. Presuming that the charge has a mis-fire, and going too soon to investigate it.
3. Tamping too tightly near the explosive charge.
4. Forcing cartridge into too small a hole or using a metal tamping rod.
5. Thawing dynamite before an open fire, blacksmith’s forge, in an oven, or by the heat of the sun’s rays through window glass.
Detonators.
A Few Causes of Accidents with Detonators.
1. Attempting to draw a wire from an electric detonator.
2. Attaching a fuse to a detonator carelessly.
3. Trying to destroy a detonator by striking it with a stone.
4. Finding a detonator and tapping it to see if it is good.
5. Holding an electric detonator in a gas flame.
6. By treading on a detonator a number of them have been known to be exploded in the same room.
7. By pricking the composition in a detonator with a pin.
8. A spark from a miner’s lamp falling into a box containing fuses and detonators has been known to explode them.
Shipping. When it is desired to ship explosives from point to point by wagons or other vehicles, it is necessary to inspect the wagons and ascertain that everything is in order and good repair, to make sure that the platforms of the wagons and inside of the wagon-boxes are free from protruding nails or pieces of metal that would tend to cause friction on the cases. A bed of straw should be prepared and the cases placed on their flat side, right side up, without any space left between that would permit of displacement or cause friction by the moving of the wagon in transportation. Horses used for this purpose should be quiet and well broken, and care taken that harness and accoutrements are in a good state of repair. Roads should be chosen as far as possible that do not lead through towns or thickly inhabited parts of the country. In wet weather it is necessary that the load be covered with tarpaulin, and in hot weather with white canvas to minimize the effect of the sun’s rays. On reaching the destination, wagons should be carefully unloaded and straw removed to a safe distance and burned. In arranging for transportation by rail or boat, the car or the boat, as the case may be, should be thoroughly examined and not entrusted to the dangerous load unless you are absolutely sure it is in good order. In unloading make sure that no vacant spaces occur between cases that would permit of shifting or friction, and should the entire floor of the car or boat be not occupied with the cases the load should be fenced or blocked in such a way as to prevent it shifting and ensure against friction. Should any packages of explosives, when offered for shipment, show outward signs of oily stain or other indications that the absorption of the liquid part of the explosive in the absorbent material is not perfect, or that the amount of liquid part is greater than the absorbent can carry, these packages must under no consideration be loaded, and must be immediately removed to a place of safety and the parties who supplied them immediately notified thereof. The car containing explosives must be labelled as such in a conspicuous manner and must be hauled as near the middle of the train as possible, and must not be placed next to a car containing oil or inflammable material. A flying switch must not be taken with explosives. In case of a wreck every precaution must be taken to prevent fire. While most of the high explosives burn quietly when lighted in small quantities, and without causing disastrous explosions, it must be remembered that it is not a safe experiment.
Storage. Local conditions have much to do with the type of structure to be built for an explosives’ magazine. In general, it may be said that the lighter the construction the better. The laws of some countries require that all magazines be built of such material, and in such a manner, that in the event of an explosion the building will be completely disintegrated and no pieces thrown to any great distance. Storage in caves, tunnels, earth or stone-covered vaults, and in log structures, should under no circumstances be tolerated. The chief objection in all these cases is that the structure will hold dampness, and any dampness in a magazine containing explosives into which nitrates enter as an essential or accessory ingredient, is certain to affect its quality and render it more or less dangerous in subsequent use. This applies to gunpowder and to practically all dynamites, especially those made in America. It does not apply to Kieselguhr Dynamite of foreign manufacture. When it is desired to protect a magazine from rifle fire, the magazine may be banked with earth to an extent that would be proof against bullets, and to a height well above the cases as arranged in the magazine; arrangements being made for perpendicular air-shafts through the embankment next to the outer wall at intervals necessary to give the required ventilation; ventilating shafts being screened with fine wire netting to exclude vermin and constructed in such a manner that water cannot enter. Explosives should be stored in tiers, box on box, with laths between to prevent dampness accumulating. No cases must be opened in the magazines, a separate building being provided at a safe distance for that purpose. Gunpowder and dynamites in unopened cases, and fuses securely boxed, may be stored in the same magazine, but no fulminates in the form of caps, or otherwise, or loose coils of fuse, should ever be stored in the same building with gunpowder and high explosives. It is important that the magazine be kept clean, and that no men with nails in their boots be allowed to work in a magazine. No fires should be lighted or smoking allowed in or about a magazine containing high explosives.
