A working party, 1916 (c).

A working party, 1916 (c).

Royal Engineers repairing a bridge.

Royal Engineers repairing a bridge.

Hauling a 60-pounder on the Somme, October 1916.

Hauling a 60-pounder on the Somme, October 1916.

A British Army wiring party, 1917 (c).

A British Army wiring party, 1917 (c).

Royal Engineers repairing a bridge.

Royal Engineers repairing a bridge.

Sappers and miners at work on a tunnel, April 1915.

Sappers and miners at work on a tunnel, April 1915.

Scottish troops carrying out road repairs on the Somme, 1916.

Scottish troops carrying out road repairs on the Somme, 1916.

Soldiers dug in at Chocolate Hill, Suvla Bay, Gallipoli, 1915.

Soldiers dug in at Chocolate Hill, Suvla Bay, Gallipoli, 1915.

R.E.'s mine and counter-mine Messines Ridge, 1917.

R.E.’s mine and counter-mine Messines Ridge, 1917.

Royal Engineers bridging a stream, 1917 (c).

Royal Engineers bridging a stream, 1917 (c).