CHAPTER IX

FIREWORK ACCIDENTS

The record of firework accidents until the date of the Explosives Act, 1875, is very meagre, not in subject matter, as reference to Chapter VI will show, for the history of the industry up to that time appears to have been one catalogue of accidents; the only cause for wonder when one considers the conditions then prevailing is that there were not more. But in detail, the only records are more or less sensational reports of the event, and such explanation of the cause as the reporter could pick up from some bystander.

In some cases where the workers were not killed the explanation was found to be simple; as for instance, the accident at Mortram’s works in 1821. Here a boy who was making stars in a room with several other workers and other composition present, put some of his work to dry before the open fire, and as if this was not a sufficiently reckless proceeding, lit one on the hob, with the consequences that were to be expected.

In most cases, however, the cause seems to have been obscure, and little or no trouble appears to have been taken to discover the cause with a view to prevention of a repetition.

Since the Explosives Act careful record is kept of all accidents; the scene of the accident is inspected, and a report printed, setting out the cause, so far as can be ascertained.

Until the introduction of chlorate of potash about 1830, if even reasonable care had been used the chances of spontaneous ignition were very small, and it is reasonable to suppose that such accidents as did take place were in the majority due to such incidents as the above.

After that date, however, it is not too much to say that quite as large a proportion of accidents were due to the admixture of chlorate of potash and sulphur.

We are, of course, now speaking of accidents during manufacture, although to the same cause may be attributed many of the numerous cases of bursting mortars during displays which were so frequent until the prohibition of this mixture in 1894 by Order in Council 15.

Dr. Browne, of Hull, a consulting chemist, published in 1884 a book entitled, “Firework Accidents, their cause and prevention,” in which he divides accidents into three classes: mechanical, chemical (spontaneous combustion), and mechano-chemical.

Such a classification seems to the writer misleading, as all accidents must of necessity be chemical; that is to say, for combustion chemical action must take place; and with the exception of cases where ignition has taken place quite spontaneously, that is where the composition has ignited when lying perfectly undisturbed, all must be considered mechanical.

Almost any composition used in pyrotechny, however stable, can be ignited by a violent blow between two hard surfaces, but some compositions are so unstable as to be ignited by very slight friction.

It is therefore a question of degree, or whether the mechanical factor is most to blame or the chemical. A better classification would be:

I. Ignition caused by violence, friction or heat.

II. Accidents caused by the state, condition or quality of the composition or ingredients.

If the accident be included in the class which gives the fundamental cause of the accident, it will be found that the greatest number fall in Class II, even though they may at first glance appear to belong to the first class.

Class I includes accidents caused by the accidental presence of fire and accidents caused by necessarily more or less violent action in manufacture, that is to say, in charging.

Ignition during charging may be caused in two ways, either by a blow on composition between the charging tool or drift and the spindle or other hard surface, or by heat generated by repeated blows on the consolidated composition.

In this class also should be put accidents, of which there are many, caused by playing or scuffing by the workpeople, the absence of safety overshoes, the presence of grit or iron or steel implements, in fact those caused by misconduct or negligence on the part of the workers, also the rare occasions where lightning has been the cause.

Accidents caused by slight friction have to a great extent ceased to exist owing to the elimination of chlorate and sulphur compositions. Where accidents arise owing to instability of the composition, they most frequently at the present time fall within Class II, as the instability of the composition is generally due to the presence of some impurity in one or more of the ingredients.

Another source of accident of this class is the use of violence in emergency with a composition which, although not sufficiently stable for heavy charging, is quite safe for careful manipulation; as for instance, where force is exerted to clear a funnel which has become blocked with composition, or some similar action.

As regards the part played by heat in accidents of this class, a study of the records clearly indicates how great is the influence of weather. By far the greatest number of accidents take place in the summer months; hot weather and a heavy atmosphere are the most likely conditions to produce trouble for the pyrotechnist, although whether the primary cause is heat or owing to an electrical condition of the atmosphere it is difficult to say, probably it is the two conditions in conjunction. Sulphur and shellac, two very important ingredients in the art, are both capable of holding an electric charge, and it seems not unlikely that they may be so charged in an electric atmosphere during the process of mixing.

Accidents in Class II are generally less easily explained than those in the former class and have occurred in many forms. As has been said, during the period (about sixty-five years) from the introduction of chlorate of potash to the Order in Council forbidding its use with sulphur, numerous accidents occurred; spontaneous ignition, both whilst drying during manufacture and even during mixing, ignition from very slight friction, and for a time a frequent occurrence the detonation of the contents of shell by the lifting charge. During the period of seventeen years between the date of the Explosives Act and the prohibition of chlorate sulphur mixture, twenty-eight accidents are recorded, resulting in eleven deaths attributable to the use of such mixtures.

The instability of chlorate sulphur compositions, however, does not appear to be so much due to the presence of these two chemicals themselves, but rather to the presence of impurity in conjunction with them.

Commercial sulphur often contains free sulphurous acid, which acting upon the chlorate produces chlorine tetroxide, which rapidly decomposes and ignites the mass of the composition.

Other acids which produce decomposition of the chlorate are equally likely to produce ignition. Of such cases, examples may be mentioned of acid being present in the paste used for case and box-making, also in gumwater which has been kept some time before using, and in starch paste similarly treated. Spontaneous ignition has also been caused by the contact of oil with finely divided carbon such as lampblack or finely divided metals, such as magnesium and aluminium, which are so largely used at the present time.

Another case of this nature is the heating up of cases after charging with gerb composition, two of the ingredients of which are sulphur and iron borings, this heating sometimes being sufficient to cause combustion. The cause of this phenomenon is the combination of the iron with sulphur to form sulphide of iron, this action being accompanied by heat. In fact, it is the same as that producing the experiment known as Lemery’s volcano. As far as the knowledge of the writer extends, however, no occurrence of ignition has been definitely traced to this phenomenon, although it seems highly probable that even if ignition of the actual composition has not taken place, cases have occurred where more sensitive compositions have been fired by heat so generated where fireworks have been stored together.

The annual reports of H.M. Inspectors of Explosives published since 1876 form an interesting and instructive summary of accidents in explosive trades, an examination of which throws considerable light on our subject.

One is struck by the frequency with which explosions occur as a result of ignorance, generally on the part of amateur firework makers. In many cases, as where children are concerned, this ignorance is natural, but the want of knowledge and even reasonable care displayed by individuals whose occupation suggests at least some knowledge of the risk is indeed often extraordinary.

Such a case occurred in 1884 in Devonshire, when a local chemist who was illegally manufacturing coloured fire, instructed an assistant to grind in an iron mortar a mixture containing chlorate of potash and sulphur. The lad was killed in the resulting explosion.

Even more remarkable was an explosion which took place in a railway carriage in 1893. This was due to the spontaneous ignition of a quantity of chlorate and sulphur coloured fire, which was being carried in an ordinary handbag by a gentleman whose occupation in life was that of professor of chemistry.

An accident presenting considerable interest took place in 1885 at Mitcham. The cause of this occurrence was quite simple. A man was fixing the curved stick which forms the pivot upon which a tourbillion rotates to one of those fireworks. The wire nail used for the purpose penetrated the composition and fired it. The remaining goods in the shed were ignited, and communicated to the neighbouring buildings, one of which was a magazine containing 3,000 lbs. of partially manufactured fireworks, including a number of rockets. These being without sticks and becoming ignited flew in all directions, setting fire to other buildings. The result was that ten buildings and an air drying rack were totally destroyed, and three buildings and three racks partially so.

This would seem a very serious matter as far as monetary damage is concerned, but as regards the chief consideration in accidents of this kind, that is to say damage to human life and limb, the result was almost negligible; two persons were slightly injured.

This accident, which was the most extensive in any firework factory since the Explosives Act came into operation, afforded striking proof of the efficiency of the precautions instituted under that Act.

It is indeed extraordinary that in an explosive factory of considerable size, employing many workpeople, during working hours it should be possible to destroy more or less completely seventeen buildings and only slightly injure two persons.

It may be contended that the number of buildings damaged was very high, but it must be remembered that rockets without sticks take a most erratic course in their flight, rendering the effective screening of other buildings most difficult, if not impossible.

However, there is evidence that many rockets were stopped by the screens, and that without their interposition the number of buildings destroyed might have been many times greater.

The other Explosives Act requirements of which the efficiency was demonstrated by this accident, are the dividing of sheds into compartments with a limited number of workpeople in each, easy means of escape from working buildings, and the value of uninflammable clothing.

It was also shown that a large quantity of fireworks might be burnt in mass without causing a veritable explosion; as in the case of the magazine containing 3,000 lbs.

Contrasting with this occurrence are the reports of accidents in firework factories both on the Continent and in America.

The same year, at Civita Vecchia, ten persons were killed and twice that number injured in one accident at a firework factory.

Four years later, in Paris, seven girls were killed out of the eighteen employed in one compartment. The material being used was red phosphorus and chlorate. In 1882 fourteen persons were killed and no fewer than seventy injured at Chester, Pennsylvania.

From 1891 to 1894 eight accidents in the United States are reported, resulting in a total of twenty-three deaths and injury to more than fifty persons. In 1894, at New Haven, Con., damage to the extent of 125,000 dollars was done, and at Dallas a considerable part of the city was destroyed.

These are, of course, not a complete list, but only such cases as are brought to the notice of the English Home Office, but the extent of these clearly illustrates the value of the restrictions in force in this country.

During the same years the total of firework factory accidents in this country was thirteen, in which three persons lost their lives, and in no case was more than one person killed in any one accident. Indeed, in one instance only since 1875 has the number of deaths resulting from any accident exceeded two—on that occasion four deaths resulted.

An interesting type of accident, examples of which have taken place on several occasions, is that in which two compositions, one containing sulphur and the other chlorate of potash, are placed in contact in the paper case of a firework, and produce spontaneous combustion.

In one case a lance containing white and green composition burst into flame on the work bench. This provided an explanation to an explosion at the same factory which had taken place ten days before in a magazine containing between 6,000 and 7,000 lbs. of display fireworks.

An occurrence of a similar nature was observed at Brighton in 1903, when some changing coloured lights which had been removed from a building where a fire had taken place (the fireworks not being involved in any way) ignited some days afterwards.

It is thought that the lights may have been wetted during the fire, and upon drying out some days later the different compositions in contact in the case or cases set up chemical action, which resulted in spontaneous ignition. It was found on examination that a blue containing sulphur was in contact with a green containing chlorate. It may be noted here that mixtures which are damped during manufacture are more liable to spontaneous ignition than those manipulated in a dry state.

Many accidents and explosions are left unexplained, either because the evidence is destroyed by the resulting fire or by the death of the witness or witnesses, or because of the difficulty often experienced in getting the workpeople to give a full and faithful account of what occurred, fearing to cause trouble for themselves or others concerned.

There can be no doubt that the cause is frequently carelessness or mistakes on the part of workers. In a large number of cases, however, this explanation gives no help and the cause remains obscure. One such may be mentioned:

In 1902 an explosion occurred in a store for non-explosive ingredients, in which were kept the chemicals used in a firework factory. In the building at the time was a workman who appears to have been engaged in sifting chlorate of potash, and the technical manager of the factory who seems to have been weighing out ingredients. There is no doubt that he was a man of very considerable experience, and from his responsible position unlikely either to take risks or be guilty of carelessness.

An explosion occurred in the building, killing both occupants, and of so violent a nature as to sever the foot of the manager and to project one of the sheets of corrugated iron with which the roof was covered a distance of thirty yards.

No explanation of this occurrence was arrived at other than that in some way some of the chemicals must have become mixed to form a sensitive and violent explosive; so much is obvious, but how the chemicals became so mixed remains a mystery, as no mixing was actually done in the building. The ignition of such a mixture is less obscure as magazine boots were not necessary in the building owing to the non-hazardous nature of the work carried on there, and sufficient friction would be produced to fire even a fairly sensitive mixture between a nailed boot sole and a wood floor.

An occurrence of considerable interest in this direction took place in a warehouse at Manchester in 1908. In the building were stored several tons of chemicals, among which were twelve tons of chlorate of potash and thirty-two of chlorate of soda.

A workman stepping down from a barrel struck fire, and saw a flame, which he tried to extinguish by rubbing with his foot. This, however, had the opposite effect. He then tried a bucket of water, which failed to put it out; he left the building and heard an explosion, followed by a second and a third, all apparently of a violent nature, all three being heard nearly ten miles away, and glass broken throughout a considerable area round the warehouse.

The cause appears to have been as follows: During the conveyance of the chlorate into the building leakings took place, and a certain quantity remained on the floor, this mixing with dust and other organic matter would prove a highly sensitive composition. This was ignited by the man’s foot and rapidly spread, probably a deposit which had accumulated under the floor became involved. The woodwork of the building and the wooden barrels then became ignited. The rapid decomposition of the chlorate caused by the heat liberated large quantities of free oxygen, which united with carbon in the smoke to form gas, which exploded upon reaching the correct proportion for so doing.

The writer has chiefly confined himself to accidents in firework factories; those occurring during the illegal manufacture of fireworks in premises unlicensed for the purpose present no further interest, and are generally caused by ignorance on the part of the participant of the often extremely dangerous nature of the material he is handling. To take an example:

Two boys were engaged in grinding in a mortar a “small quantity” of chlorate of potash and sugar. An explosion resulted which blew out the entire window frames of the room, destroyed the partition between the room and the passage, considerably damaged the other wall, and projected the pestle into the ceiling, where it remained embedded.

Accidents at displays are now happily rare; the most fruitful cause of such happenings was the detonation of shell in the mortar, that is, the detonation of the contents or “garniture” by the explosion of the propellant charge.

The elimination of chlorate-sulphur composition has reduced the chances of this to a minimum, and the compulsory burying of mortars up to the muzzle has practically eliminated the danger to either firers or spectators.

Apart from slight injuries caused by falling rocket sticks and mishaps of a similar nature, accidents to the public at firework displays are things of the past.