If, as seems not improbable, mining operations are likely to be frequently undertaken in future wars, I would suggest that the trade of miner should be re-introduced into the Corps of Royal Engineers.²²

The report of the exercise, printed at Chatham, contained many useful lessons, but as the Chief Instructor in Fortification at the School of Military Engineering on the outbreak of war, R.N. Harvey, recalled: ‘Unfortunately the report on these operations was treated as confidential and the lessons derived from the exercise were not generally known.’²³

Following the exercise the British War Office appointed a committee in 1908 ‘to consider and report as to the means for maintaining and improving the science of siege warfare.’ It recommended that Royal Engineer (RE) units be earmarked as Siege Companies and trained annually in siege exercises.²⁴ In line with this, the 20th and 42nd Fortress Companies Royal Engineers staged a siege exercise at Lulworth in June 1913, against an earthwork based on part of a fort at Port Arthur. Although not on the scale of the Chatham exercise, practical experience was again gained and a 250lb (113kg) gunpowder charge was blown. The detection of the opposing miners by listening was found to be highly subjective and means were tried to improve the effectiveness: ‘One method of listening is to drive a peg in, bite on it and stop your ears.’²⁵

A boring tool devised by Captain Rogers was tried, and found to be valuable in soft ground where the mines were within a few feet of one another, but on very stony ground it was said to be hardly worth trying.²⁶ After blowing a 100lb (45kg) camouflet the danger of carbon monoxide was a nasty revelation:

As soon as untamping began at the far end of the air space, the officer and men working began to feel giddy and faint; no fumes or smell were observable and a candle burned well; it was probable that carbon monoxide was present, and the Medical Officer and War Office Chemist, who were present confirmed this view. Work had to be stopped, it was resumed next morning, but had to be suspended at once. The Chemist gave it as his opinion that the poisonous gas might remain absorbed in the earth and sandbags for days and even weeks.²⁷

The camouflet not forming a crater, there was nowhere for the gas to vent and it remained trapped in the gallery and surrounding strata.

Renewed interest in the problems of siege warfare was reflected by the formation of a siege committee chaired by Major General Hickman, which sat in 1914 to consider the resources needed to attack a German fortress, in particular the heavy artillery requirements. It also considered engineering resources and recommended that gunpowder should remain the standard explosive for mining and that an apparatus for bored mines should be provided. The committee reported in December 1914, by which time events had overtaken it.²⁸ The war had been in progress four months and trench warfare was established along the Western Front. The impossibility of assailing field fortifications without very high casualties was proven beyond doubt and siege warfare techniques, including sapping and mining, were in progress against them.

The British issued new manuals on Mining and Demolitions and Attack and Defence of Fortresses in 1910. These incorporated some of the lessons of the 1907 exercise, but had not kept up with civilian practice in respect of technology, equipment and explosives. The authors also refused to anticipate that defensive works constructed in the field could be sufficient to stop a determined attack; defences were described as ‘storm-proof ’ where: ‘…attacking infantry can be destroyed as fast as they can approach, no matter how great their dash and determination.’²⁹

Such a work, according to the manual, could ‘only be rendered storm-proof by the construction of a deep ditch’ a notion later ridiculed by the Royal Engineer Corps History:

In short: by the methods of the eighteenth century! This too after the South African War, ten years earlier, in which Boer defensive positions consisting of simple trenches and barbed wire had proved themselves over and over again to be storm-proof! The general attitude taken up in regard to instruction in siege works was that operations in a European war would be so mobile that the necessity for siege operations would be most unlikely to arise.³⁰

This attitude extended to all the major belligerents. There were, however, some officers, mainly engineers, who recognised the difficulties that trenches and barbed wire could cause and that the attack might be held up to such an extent that mining would be necessary. A French army engineer, Captain Genez, in 1914 concluded in a historical study of underground warfare that the experience of the Russo-Japanese War suggested that mining might in future have to be used in the attack and defence of not only fortresses, but also defensive field works.³¹ This view was echoed by Lieutenant Colonel R.N. Harvey RE, the Chief Instructor in Fortification at the School of Military Engineering, who, in a lecture to senior officers in 1914 on the problem of attacking barbed wire, ended with a similar proposal:

There remains the way under, by which the entanglements may be destroyed by mining. This, I think, will be the way of the future, for it is difficult to imagine any troops again facing the carnage wrought at Port Arthur.³²

After the war Harvey described the pre-war training of RE units as:

…usually limited to 2 or 3 days and by special care this period could be so extended that a gallery of some 30ft could be completed and a mine laid and fired. The mines of course [were] driven in the most favourable soil available.

For the conditions that the British were to meet in 1914 he described this as ‘almost useless’.³³

In 1920 Toepfer, who as a Captain fourteen years before had hoped for more prominence for the technical troops, lamented the lack of preparation for mining on the outbreak of war:

When in the Russo-Japanese War the Russian Sappers advanced against individual Japanese strongpoints by mining, the fact was not really heeded that, as a development of defensive warfare, trench warfare was born.³⁴

In the world war, he said, the arena of combat for the miner shifted from the fortress to no man’s land, and mining became a weapon of major importance for commanders. Major deficiencies soon become apparent, however, with the German mining capability. There was a lack of proper principles for underground warfare and the tactical and technical training was inadequate, both at the level of command and among troops. The ‘high command frequently didn’t know where to start’. The miners were competent at sinking shafts and driving tunnels at shallow depths through easily workable soil, but ‘experience was lacking’ and the impact of geological strata and water levels were insufficiently studied or considered. Technologically the military had fallen behind the civilian mining industry and so the equipment available was not remotely adequate for a vigorous and intense mining programme: ‘It was not easy to find civilians with mining experience involved in the military effort.’ Finally, the pioneers alone could not deal with the situation:

The trained pioneer mining personnel were not numerous enough by far and the engineer field companies were by training and number unable properly to increase mine warfare to the full extent, so that professionally trained and also untrained auxiliary workers had to be called on.³⁵

Toepfer’s analysis of the shortcomings of German mining on the eve of the war also reflected the ability of the Germans to respond to the shortcomings. The assimilation of civilian mining experience and technology into the armed forces was to be a deciding factor in the coming struggle.