High on the moor at Silloans, within the Otterburn Training Area, lies the well-preserved remains of a trench system.
Seen from the air, it includes the classic layout of the First World War trench system, with front, support and reserve lines oriented to face the enemy, as well as communication trenches linking them to the rear areas.
The trenches posed a number of questions to the staff on the site about their origin, preservation and importance. As documentary research had failed to provide the answers, it was decided to conduct archaeological research. Defence Estates contracted the group No-Man’s-Land: The European Group for Great War Archaeology to work along side them in investigating the remains.
Superficially, the trenches are of Great War date (1914-1918), as they are of the right appearance; however, research elsewhere has shown that such fieldworks were being used for training until World War Two. There was no information available about specifically why they were dug, as training can take many forms: trenches could be dug for practice in construction, for combat training, as an exercise in surveying and siting, or as a way of raising levels of fitness and esprit de corps in the men. The appearance of the trenches was also a question: would the Silloans set conform to the plans proposed in the Army’s manuals? The raison d’etre of the trenches also raises the question of how they were used, since prolonged use in exercises would be expected to result in artefact scatters, including cartridge cases and grenade fragments, food tins and elements of uniforms and equipment. Finally, there was a question about the identity of the men who actually dug the trenches; would it be possible to identify the unit involved?
Five trenches were dug across the earthworks to see how they had been constructed and to seek evidence of use. The Front Line trench revealed a wide, deep trench with no obvious revetment to hold the sides in place. This area produced no significant finds to say anything about its usage. However, this trench has been altered in more recent years to create placements of training equipment on the ranges, so it is probable that it has been adapted and re-dug, obliterating earlier remains.
Works around the island traverse showed a very complete section of trench with evidence of well-made revetment, trench boards on the floor, and a fire step. The trench here was two metres deep, deeper if the parapets formed by upcast soil were taken into account. As such, they offered excellent cover but were too deep for defence; so, the fire step, dug out on the external face of the trench, allowed men to step up and both see and fire. Interestingly the step seemed to have been dug in yard-long sections (1 metre) as one section was slightly deeper than the others, shelving away from the edge. In the rain this formed a nice puddle, rendering this part of the step useless as a seat or shelf, which Great War photographs show that they became when not in more military usage.
This trench had also been very well-built, as a series of postholes and remains of thick twists of wire showed. These represented remains of the revetment of the trench sides to stop them falling in. There were numerous methods of supporting trench walls, but the method encountered at Silloans was identical to a method shown in the 1916 Field Fortification Manual. However, it was the only area excavated that was made to this standard. The posts were used to retain the walls and each one was tied back to its neighbour, before the uppermost post, which had been secured in a hole on the firestep, was tied back to a stake in the solid ground beyond the trench. The drawback to this method of construction was that it was both labour and resource intensive and required skilled soldiers, while one well-placed shell could undo hours of work.
Trench three proved disappointing in that the possible dugout was sectioned and shown to contain relatively modern ammunition and food wrappers. The suggestion from the soldiers working alongside the team was that it bore the hallmarks of an observation post, where troops had spent several days during an exercise. The location of the fourth trench had been chosen because it had an irregular profile in the earthwork. The feature was sectioned and was shown to extend back from the line of the trench, creating a recess some 4m wide. Remains of planking separated the trench from the feature. While nothing was found to confirm the origin of the feature, the presence of pieces of artillery shell suggested that it was damage caused by a shell and subsequent repair. In terms of training, repair of shell damage was a useful thing to learn, but it shows that the trench had multiple uses as infantry training and their use as an artillery target would not have happened at the same time.
Finally, the second or Support Line trench was investigated. Excavation showed it to be narrow, basic and without evidence of revetment. However, remains of a distinct firestep were revealed suggesting some engineering, at least to support a feature that could be easily eroded by the troops as they used the step.
For the full article, see CA 232