Our second Zoom meeting welcomed Mark from the National Coal Mining Museum. His subject, the flame safety lamp, has become an iconic image, a metaphor for the mining industry as a whole, but throughout its long development it has seen many changes to make it more safe and efficient.
With the increasing depth of underground workings in early mining, lighting gradually became more important. Oil lamps were used, but a light with a flame could be dangerous when pockets of accumulated gas were present, particularly methane, known as fire damp and the product of plant material decomposition. To pre-empt fires and explosions a fireman was sent ahead in the early years. He would be drenched in water and carried a candle on a wet stick in order to find these pockets. There were attempts to find alternative solutions. In the 1760s a machine which created flint sparks was invented but this still required a person to operate the machine.
The mining industry was growing rapidly in the first decade of the nineteenth century and there were technological developments in pumping and ventilation, but not at that time in the problem of safe lighting. It was a time of many mining disasters but these were not widely reported and there was almost no legislation relating to coal mining, although campaigning began in this decade from voices outside the industry. In contrast continental mining was already becoming subject to legislation. It was a disaster at the Felling Pit in Durham which made national coverage when 92 men and boys were lost to fire damp ignited by a naked flame. This led to the foundation of the Sunderland Society for the Prevention of Accidents in Coal Mines. Begun by the Rev John Hodgson the Society was supported by the Duke of Northumberland, a major mine owner in the area, among others. At the first meeting in 1813 a competition to design a lamp was initiated.
A Dr Clanny had already designed a lamp in 1811, but it was large and impractical. Sir Humphry Davy was then the most important scientist in Britain: President of the Royal Society, Lecturer at the Royal Institute, knighted at 33 and a baronet at 41. His discoveries of potassium, sodium and calcium had made him into a celebrated public figure and he was asked to consider the question of a miner’s lamp. George Stephenson also accepted the challenge: working as an engine wright at Killingworth Colliery and still unknown, he proceeded by trial and error, unlike Davy. All three men were studying the same problem, with the main competition between Davy and Stephenson who began to trial prototypes, for which they were quickly rewarded by mine owners and the scientific establishment.
As we know, Davy’s name is now associated with the lamp and this was because he introduced the use of gauze which contained the flame so that it could not ignite gases outside, although oxygen could come through the gauze to keep the flame alight.
These lamps were registered for use quickly on the continent but in Britain the take-up was most general in the North East but elsewhere very patchy. It was not until 1835 that Parliament stated that the lamps were to be used in mines as a precaution when gas pockets were being identified. There remained major shortcomings with the lamps being made at this time. It had been clear from 1816 that strong air currents might push the flame through the gauze and the gauze itself could overheat. No single design of lamp had been patented so that some makers used the wrong quality of gauze. Accidents were still happening.
In 1835 a Select Committee was set up to explore accidents in mines – the first time the government had looked fully at the problem. Their findings were that 447 lives had been lost before 1817 and since then 538 men and boys had died. It was noted that the lamp did not eliminate the hazard, and might encourage entry into more dangerous areas. The industry had been growing enormously; not all workmen had the experience of how the lamps worked. This expansion had also led to engineers not paying enough attention to good ventilation.
Thus the lamps continued to be redesigned in the 1830 and 40s. Light levels, dimmed by the gauze, were improved by the use of lenses; overheating of gauzes was addressed with double gauzes; and flames were protected from air currents by the increasing use of glass. In 1839 Clanny, who had continued to address lamp design, made a significant improvement by introducing a portion of glass to replace the gauze, although this brought its own problems with darkening glass. In 1740 Muesler’s lamp had an internal chimney, which was a major improvement except that it would go out if tilted. Gradually more successful lamps were being manufactured into the 1860s but in England there continued to be no control over the quality of many types of lamp manufactured or used.
From 1836 to 1841 a Belgian Commission approved 3 lamps to be used in Belgian mines. In England in 1839, following the death of 51 miners, the South Shields Committee found the Muesler lamp was the best available and suggested that a naked Davy was dangerous. As a result of Lord Shaftesbury’s Royal Commission investigating children’s employment the first national mining legislation was introduced, but this did not address the question of lamps. It was not until the 1870s that naked flames in mines were banned as a result of a Royal Commission into Accidents in Mines. This enquiry also linked poor lighting in mines with the eyesight problem of nystagmus. The brightest lamps still compared badly in light level with the naked flame. Another issue which worsened over time was the question of air currents in mines. Ventilation in deeper mines created much stronger air currents which would affect lamps. It was decided that unshielded lamps were unsafe and should be prohibited but no particular lamp was adopted. However by 1882 the Marsaut lamp, which was an adaptation of the Muesler lamp, was used as prototype for later lamps.
Even by 1886 the use of lamps was still left to individual managers of mines. However this was the period of the rise of electric lamps which gave a better light but lacked the gas testing facility. Eventually in 1911 precise laws were brought in stating exactly the circumstances in which safety lamps should be used. At the same time there was an overhaul in gas testing and Home Office approval was required for lamps testing for gas underground. This was a turning point in legislation and lamp design, reducing the number of types of lamp and streamlining their manufacture. From the 1880s to the 1920s was the peak period for the use of flame safety lamps. Electric lighting for mining was still large and cumbersome. However in 1920 the introduction of the cap lamp and battery was very popular with workers, and quickly became the norm.
Equipment for gas testing was still required and so the use of flame safety lamps has continued until the present. The main focus of lamp development was then to improve its capability as a gas tester so that there was a much-reduced market for the lamps. After nationalisation the Coal Board used only three lamp manufacturers.
In summary Mark outlined the impact of these lamps: they had never been a successful light, they were not universally embraced, and were never the perfect answer. It was however, the first and most accurate tool for detecting the presence of gas and it therefore saved many lives.
A variety of questions followed:
Were carbide lamps used? Carbide lamps were more prevalent in foreign mines where there is less need for safety lamps. British mines are very gassy with far more problems with methane.
How much were the lamps? The expense of the lamps was met by the colliery companies and therefore did not trouble the miner’s pocket. Later models were about £50- £75.
What sort of fuel was used? There was improvement in the oils used in the lamps for a clean burn and bright light, for example naptha.
When did the use of canaries end? The use of canaries only began at the beginning of the 20th century, and was only phased out in the 1990s. The local Mines Rescue team used canaries until the closure of the pits.
Where did the words describing gas originate? Damp comes from the German dampf and means air or gas. There were several descriptions of types of gas such as fire damp, usually methane, stink damp with a smell of rotten eggs, or white damp which was colourless. The terms came from the miners themselves. Lesley Taylor