Making Dynamite Cartridges

The Cartridge Houses
After being rubbed through the sieves the dynamite becomes a finely divided greasy, coffee-colored earth. It is now the dynamite of commerce, and is ready to be made into cartridges. As you approach one of the cartridge houses, which are small white one-story buildings, you hear a tremendous thumping. You ask your guide in some perturbation if it is a good day to at cartridge houses, but he smiles and says that the noise is merely the cartridge machines.

The hut is about ten feet square, with a single door. Four girls are at work. Against the right and left walls are four spring pump-handles about the weight of a girl’s head. Each pump handle when pulled down forces a brass rod through a small conical hopper of loose dynamite fixed to the wall, and jams a portion of the dynamite down a brass tube at the bottom of the box.

The girl wraps a small square of branded parchment paper around the bottom of the tube, folding it at the lower end. Then holding the paper with one hand, and jumping up and down as she works the pumping-handle with the other, she pushes dynamite down the tube till the paper cylinder is filled to a depth of about three inches. She then removes it, folds down the top of it, drops it through a slide in the wall, whence it rolls down into her own special box a finished cartridge.

She replenishes her stock of dynamite with a scoop through a sliding door in the wall, from a box of loose dynamite which the runner has placed in a closet chest immediately outside. The girls work with the greatest rapidity. The sliding brass rod is actually lubricated with nitroglycerin. To see this operation – the brass rods flying up and down, damp with nitroglycerin, and dynamite being forcibly jammed down a brass tube – entirely destroys your appetite for further knowledge. It is incredible, and you want to go away, outside the "Danger Area," and think it over.

But your guide takes you instead to a blasting gelatine cartridge hut. Here blasting gelatin, a yellow, tough elastic paste, which consists of about seven per cent. Of nitro-cotton and ninety-three of nitroglycerin, is being forced through a sausage machine, chopped, by hand, into three-inch lengths with a wooden wedge upon a lead-covered table and wrapped into cartridges, at the greatest speed.

Blasting gelatin is fifty per cent. More powerful than dynamite, and the effect on your mind is to make you exactly fifty per cent. More uncomfortable than before; to multiply by one and one-half your desire to get away before any contretemps occurs which you would be in no position to either explain or avoid.

There are forty-five cartridge huts, all heated by steam to not less than fifty degrees Fahrenheit. Nitroglycerin congeals at forty-three Fahrenheit and freezes at forty, so the huts must be kept warm. If the dynamite were allowed to rest against a steam-pipe an explosion might follow, and the pipes are carefully boxed, and the thermometer is always watched by the eye of authority.

In addition to dynamite and blasting gelatin cartridges, the company manufacture cartridges of gelatine dynamite and gelignite, combinations of nitroglycerin, nitro-cotton, nitrate of potash, and wood meal. The gelatin explosives are specially adapted for use under water, being entirely unaffected by dampness of any kind. The company also make Ardeer powder and carbonite – explosives for blasting purposes in fiery coal mines, with a lower percentage of nitroglycerin than dynamite. The output of explosives of all kinds is an average of about one hundred tons per week.

Making nitro-cotton on a massive scale
Nitro-cotton, which by itself and in combination with nitroglycerin as cordite and Ballistite is rapidly displacing gunpowder in every direction, is made and used by the ton at Ardeer. It is made from cotton-waste, the waste left on the spindles in the cotton-mills. This comes to Ardeer in bales, like bales of finished cotton, and is first washed, to remove all grease and dirt, carded, and reduced to a homogeneous mass in a big mill devoted to these processes.

Then it goes to a great barn-like building where it is turned into soluble nitro-cotton or insoluble gun-cotton, as may be desired, the process taking place in small iron pans or hundreds of earthenware jars. Half the floor is taken up by the jars, which sit side by side in a shallow tank of cement about a foot deep. The object of this tank is to keep the jars cool by surrounding them with water during the nitration. Along one side of the room are the acid taps and lead pans.

Four pounds of cotton are placed in a pan, and one hundred and fifteen pounds of mixed sulphuric and nitric acid are added. In a few minutes the chemical combination takes place, the acid is poured off, and the nitro-cotton receives its first washing. From this point, until every particle of acid has been washed out of it, it is liable to burn spontaneously at any instant. As one of the workmen dumps the pan load into the centrifugal or acid separator, it may go up with a flash and a great column of yellow smoke; and this not unfrequently happens, but does no great harm except, perhaps, to beards and eyebrows.

It takes fire slowly and gives full warning. It now goes to another department and is washed repeatedly, kept for a week in water tanks, pulped in ordinary pulping-mills, and dried in rotary centrifugal machines until all but thirty per cent. Of the water is eliminated. The remainder is dried out of it on the shelves of a great drying-house, where a temperature of from 100 to 120 degrees Fahrenheit is maintained by hot air through fans.

At Ardeer this nitro-cotton is used in enormous quantities in combination with nitroglycerin to make blasting gelatin, of which it contributes seven per cent.; and Ballistite, which consists of sixty per cent. Of soluble nitro-cotton and forty per cent. Nitroglycerin. The extraordinary affinity of soluble nitro-cotton for nitroglycerin is a curious chemical fact.