CHAPTER VIII

MODERN FIREWORK MANUFACTURE

Fireworks are now manufactured under the Explosives Act of 1875 and Orders in Council No. 2 and No. 4 under that Act.

Order in Council No. 4 deals with small Firework Factories, the total contents of which, either finished or in course of construction, do not exceed 500 lbs. This class of factory presents little of interest for consideration; and is governed by practically the same rules as are the larger establishments of the kind, with such modifications as are justified by the small quantity of explosive material involved.

Order in Council No. 2 sets out the general rules to be observed in factories licensed under the Act, the leading points of which are as follows:

The absence of iron or steel in any workshop, carriage, or boat; cleanliness and absence of grit; care as to material liable to spontaneous ignition; provision of lightning conductors on magazines; tools and implements to be of soft metal; working clothes without pockets; shoes without nails; searching or means to prevent the introduction of matches or dangerous substances into the works; materials and finished work to be removed from working buildings and not allowed to accumulate when any particular process is completed; no person under sixteen years to be employed or enter any danger building. Every building to be provided with a set of these rules, and a statement of the quantities of explosives and ingredients, and the work to be carried on in it as allowed by the license.

The modern factory is generally situated in a rural district on account of the fact that it is more easy to observe the statutary distances from protected works. Protected works referred to in the Act include other workshops and magazines in the factory, and also dwelling-houses, factories, institutions, railways, highways, and various undertakings and buildings, the distances to be observed varying with the nature of the protected work from public highways to palaces or houses of residence of the King, his heirs and successors. In some cases, as with private dwelling-houses, the distance to be observed is about half, if the consent of the occupier to the erection of the factory building or magazine is obtained.

Firework factories, in fact all explosive factories, are constructed on the principle of limiting the scope and effect of any explosion that may take place to the smallest possible quantity of material and to the smallest possible risk to human life.

The working buildings are constructed with a door at either end to facilitate escape in case of danger; the quantity of chemicals and of partially or wholly finished fireworks is strictly limited, as is the number of persons employed in the building. This number varies with the nature of the operation being carried out, from one in the case of the most hazardous to six in some cases.

The working buildings are of light construction; the form most in use is a timber framing lined with matched boarding and covered externally with corrugated iron. No iron fittings are used, or iron nails left exposed in the interior. The floor is covered with linoleum, which is secured by copper tacks.

The distance separating working buildings is, generally speaking, twenty-five yards, or if a suitable screen is placed between two such buildings, this distance may be reduced to twelve yards.

The workpeople are provided with non-inflammable outer garments, no pockets are allowed, and suitable overshoes of sewn leather or indiarubber are provided.

All tools are of soft metal, such as brass or copper, or of wood.

The regulations refer, of course, only to those buildings in which explosive work is carried on, that is to say, buildings in the danger area as distinct from the non-danger area.

The buildings in the danger area are working buildings, drying-rooms, expense and factory magazines. Expense magazines are those which are licensed for a comparatively small quantity of explosives, and from which explosive material is drawn as the work of the factory demands, or into which is put partially or wholly finished work either awaiting completion or transference to the main or factory magazines.

The non-danger area includes stores for chemicals, paper, and other material, also case rolling and drying sheds, sawmill, wood-working and paper-cutting shops, offices, and similar buildings.

The manufacture of fireworks begins with the making of the case or container, which, with the exception of shells and Jacks-in-the-box, are cylindrical in form.

What are known as “small goods” are “dry-rolled,” that is, the outer edge of the paper only is pasted. They are then rolled up on a metal former on a slate slab.

The larger cases, such as rockets, gerbs, and Roman candles, have the paper pasted all over, which is rolled up on the former and consolidated by repeated rolling between the slate slab and a board provided with a handle.

There are two methods of introducing the composition into the cases—filling and charging.

Filling is used where the composition does not have to be consolidated, and is done with a wire and funnel, or as it was formerly called, a “tun dish.” The funnel has its outlet of such a size as to fit the case to be filled, the wire or rod is somewhat smaller than this outlet, and is provided at the upper end with a knob for the hand. The end of the funnel, which is filled with composition, is inserted in the upright case. The wire is then drawn up, thus freeing a small quantity of the composition which runs down into the case, the lowering of the wire pushing it into position. In order to render the downward movement more effective, the wire is often notched, but it is doubtful if this actually increases the efficiency. This action is rapidly repeated until the case is filled.

This method, although simple, is very effective, and in the hands of a practised worker is exceedingly quick.

Charging is adopted where the contents have to be solidified in the case. The composition is introduced in small quantities with a scoop of suitable size and consolidated by repeated blows with a wooden mallet on a “drift.” The drift is a cylindrical wooden tool of a size to fit the case, and an enlargement at the upper end to receive the blow of the mallet.

The methods of charging the various forms of fireworks will be dealt with later under their separate headings.

The method of charging rockets in use in the sixteenth century are those of to-day, and it is remarkable that no satisfactory alternative to hand charging has yet been devised. Mechanical hammering and hydraulic pressure have both been tried, but so far with limited success.

Stars which are used in Roman candles and as garniture for rockets and shells, are of many kinds and combinations, but with the exception of some which are in effect complete miniature fireworks, they are constructed on one of three methods—they are either “pumped,” “pinched” or “charged.”

The pump used in the first of these operations consists of a short metal tube, which fits exactly a short metal plunger provided with a knob for the hand, and a small metal stud at the side. The tube has a slot cut partially down the side to receive this stud.