16. WORKING PARTIES.—(a) All work on a fire trench will be carried out by the garrison of the trench, assisted, if necessary, by the garrison of the support and reserve trenches.
(b) All work in rear of fire trenches will be carried out by the garrison of the support and reserve trenches.
(c) If possible, working parties will consist of complete units, i.e., section, platoon, or company. Each unit will be commanded by its own commander.
(d) Even when working under engineer supervision, Infantry officers in charge of working parties will be responsible that the work done satisfies tactical requirements.
17. WORKING PARTIES OUTSIDE THE FRONT TRENCH.—(a) A covering party will always be provided for digging and wiring parties outside the front trenches.
18. PRECAUTION WHEN ONE OF OUR MINES IS EXPLODED.—In the event of one of our own mines being exploded, a clear space of 5 yards will be kept on either side of the mouth of the mine shaft.
19. RATION PARTIES WHEN FOUND FROM FRONT TRENCHES.—Usually, rations and stores will be carried up to the trenches by supports and reserves. If this is not possible and it is necessary that men from the front trenches have to be employed, not more than 10 per cent of the men in the firing line are to be away from the trenches at the same time.
20. RATIONS AND COOKING.—(a) Ration parties from the support and reserve trenches will be made up in complete units as in 16 (c).
(b) The company quartermaster sergeant will accompany the ration parties for his company and report his arrival to the company commanders.
(c) Great care is to be taken that ration and carrying parties make as little noise as possible.