The instruction
SECRET typed instruction from 3rd Canadian Infantry Brigade headquarters, 7 August 1916, on holding the crater at 42
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3rd Canadian Infantry Brigade · the Ypres salient · 7 August 1916

Instructions for a Crater

1916–1917

Through the summer of 1916 the Canadian Corps held the southern edge of the Ypres salient, a stretch of front where much of the fighting had gone underground. Both sides tunnelled beneath the other’s line and fired charges; each “blow” left a crater that then had to be seized, drained and fortified before the enemy could do the same. The trench maps carried the larger craters as numbered features: here, 39, 40 and 42.

This is the brigade’s instruction to the 16th Battalion, holding those craters, with a copy sent to the officer commanding No. 3 Field Company, Canadian Engineers (Robertson’s company) because the engineers found the material and the men for the work it orders: clear the front lip of the crater at 42, wire its inside, build the rear parapet up into a fighting position, and keep counter-attack and consolidation parties standing by for the next blow at 39 or 42. The working party was to start at dusk and be carried on by the incoming battalion. The brigade was being relieved. Within days Robertson’s company had left the salient for the Somme; the diary picks the move up on 11 August.

Transcription
B.M.7-3. SECRET.
Headquarters, 3rd Canadian Infantry Brigade.
7th August 1916.
16th Bn.
1. Forwarded for your information and action.
2. As regards para (3)
(a) you will arrange to clear the front lip of the Crater at 42, leaving only 2 sentries at each corner of the front lip.
(b) wire the inside of the crater.
(c) make good the rear parapet of the crater as a fighting position, and place standard frame dugouts in rear of the parados for the garrison. Until these are completed the garrison will probably have to be reduced.
3. As regards para (4) separate counter-attack and consolidation parties with tools and material should be detailed in readiness for a “blow” at either 39 or 42.
4. Please hand over these instructions to the incoming unit, together with a detail of your arrangements.
A copy of the arrangements made by you, showing the altered distribution of the garrison of 39, 40 and 42 is to be forwarded to this office by 7 p.m. this evening.
A special working party [the typed word “wiring” struck through, “working” written above] should be detailed by you to start this work as soon as it is dusk. It will be carried on by the incoming Battalion.
The O.C., No. 3 Coy. C.E., has been given a copy of these instructions, and will supply such material as may be necessary.
[signature] — Major, Brigade Major, 3rd Canadian Infantry Brigade.
Copy forwarded to O.C. No. 3 Field Coy. for information.
The diary: the move south from the salient, 11 August 1916 →“A Wiring Party”: his own wiring scheme →

The original is in the Treherne family collection. It is the brigade’s covering instruction, passed between the relieved and relieving units; the underlying scheme for craters 39, 40 and 42, to which its paragraphs refer, is not among the papers. “SECRET” markings on operational papers of this period are historical. Records of this kind are held openly at Library and Archives Canada.