The first step is to overcome a man’s natural fear of the grenade itself. This is only done by explaining how it is to be used, the method of lighting and the length of time taken for the fuse to burn. A good idea is to have some of the fuses of the length used lighted and the men told to count while the fuse burns out. Dummy grenades with fuses attached can then be introduced and the men taught to light them, observing carefully how long it takes for the fuse to burn down to the grenade.

The second step is to develop accuracy in throwing. Normally, the bomb should be bowled overhand, although it is certainly not wrong to throw, but it has been found in tests that a man throwing bombs has tired a great deal quicker than a man bowling them overhand.

Stick grenades may be thrown over short distances like a dart, although this is unhandy and can only be done by a carefully trained man. Great care must be taken while in the trenches in throwing percussion bombs, as very often a man swinging his arm back to throw such a bomb has exploded it in the trench, with disaster to himself and those near him.

Men should be taught to throw standing, kneeling and prone. It should be impressed upon them from the beginning that if a grenade with a time fuse is dropped in the act of throwing there is ample time to pick it up and throw it out of the trench before it explodes, but this must be done immediately.

A is a diagram of a bombing field where men are trained in practice with dummy bombs. 1 is the target marked on the ground and having the same general plan as a firing target, with Bull, Inner, Magpie, and Outer, the score counting 5, 4, 3, & 2 respectively, or according to the instructor’s taste. 2 is the first line, 20 yards from the center of the inner ring. The men must be trained to a high degree of accuracy at this range. 3 is the second line, 25 yards from the center of target. There are lines every five yards back until the 40 yard line is reached, which latter is the extreme range for bombing practice.

At each range the men should practice standing, kneeling, and prone. At 35 and 40 yards bombing from the kneeling and prone positions is very difficult and the time spent on practice here should not interfere with the obtaining of great accuracy at the shorter ranges.

At all ranges the men should be allowed to throw any number of dummy bombs, but should not be permitted to fatigue their arms.

B is a diagram showing the arrangement for trench practice with dummy bombs. Small trenches are built on the surface of the ground by screens of wire mesh covered with burlap or other similar material. 1 is the thrower’s trench and is built so high that he cannot see over the top. From this he throws, using a periscope for observation. 2 represents part of a traverse and fire-bay, the front part of which is about 20 yards from the throwing trench. 3 is a section of straight trench about 25 yards half right from the thrower’s front. 4 is a section of curved trench about 20 yards half left from the thrower’s front.

The general custom in the practice trenches is to give the man any desirable number of dummy bombs, say 18; 6 for each trench. Four out of six are required to be put in No. 2, and 3 out of 6 in Nos. 3 & 4. Men must not be kept at bombing practice too long at a time as it spoils both their interest and their aim.

In taking a line of trenches, it is well to remember that the attack will take place on a relatively small front by a large number of men, and therefore when the trenches are finally reached, there is liable to be great overcrowding in them. This can only be prevented by extending them along the trenches as quickly as possible, and is of the utmost importance as heavy casualties will result from allowing this overcrowding. To make this extending possible, it is the duty of the bombing parties to work along to both flanks of the trenches and take advantage of the temporary confusion of the enemy by obtaining as much of his trenches as possible, thus allowing for the extension of men. In a narrow trench the only portion of an attacking party coming into contact with the enemy is the head, or what is known as the Bayonet Man. The bombing party is composed of the following:

1. Bayonet man,
2. First thrower,
3. First carrier,
4. First spade man,
5. N.C.O. first squad,
6. Second bayonet man,
7. Second thrower,
8. Second carrier,
9. Spade man, in charge of second party.

These parties will work up a trench until they come to a junction, when the first party in charge of the N.C.O. will continue straight on and the second party branch to the right or left, as the case may be, and as they come on other parties keep working up behind them, and the infantry gradually following taking possession of the line and starting consolidation work at once.

Communication throughout these lengths of grenade parties is very difficult with men extended in single file, and the attendant confusion which accompanies such a stand.

A system is required which will enable supplies of bombs to be passed up and casualties replaced automatically. This system cannot be laid down on any cut and dried lines, but must be figured out before the attack, with due consideration being given to the line of trenches to be attacked and the difficulties which will be encountered in getting supplies to that line, and it is only on the spot that such a system can be worked out.

During an attack three grenades per man are issued to each unit detailed to open the attack, and these grenades are turned over to the bombers or used by the men themselves if necessary. When out of grenades themselves, the men take over the casualty’s, and it is the duty of a casualty when he is so able to, to leave his grenades and ammunition to the care of some other man before “going down.” Small depots should be established at frequent intervals along the trenches from which the attack starts, with careful consideration given to their safety from shell fire, if at all possible. Other depots must be established in the support and assembly trenches, and these will generally be supplied through a central station probably controlled by a brigade or division.

Before starting the attack, every man and party should have had explained them in detail exactly what is required of them, and generally the following system is adopted:

First bombing party of group—

Two bayonet men to protect grenade throwers,

First bomber,

First carrier,

Second bomber,

Second carrier,

Group leader (N.C.O.),

Two bayonet men to protect the group leader and the rear of party.

* * * * *

Second bombing party—

Formation as above. The head of the party must be in touch with the rear of the first party. Officer commanding in rear of second party.

* * * * *

Third and fourth bombing party—

Formation as above. Second in command in touch with rear of fourth party.

Machine gun detachment, if available or considered necessary.

The machine gunners are generally used at the rear of a party, so that they can bring their guns into action from behind and sweep the top of the ground around the trenches being attacked, in order to prevent an overland attack on the bombing party. In all these formations the number of men detailed must allow for casualties. Rapidity of movement is essential, as crawling and stalking will give the waiting enemy an advantage. The leading bayonet men generally move along the trench, from corner to corner, in a succession of rushes, followed by first bomber, and the thrower hurls as directed by the bayonet man. The duty of the bayonet man is to protect the thrower and carrier at all costs. Second bomber and carrier follow the leader, keeping one corner behind to replace casualties. Each party must be regarded as reserves to the party in front, and some method must be found every time a new attack is carried out for giving the aerial service notice of trenches occupied. If the head of a party is checked, that which has been gained must be held by throwing up a barricade. In all attacks bombing parties are supported by a party of sandbag men, under an experienced N.C.O., so that while bombers keep the enemy at bay a strong barracade may be put up as quickly as possible.

This is generally done by placing what is known as a demolition tube about 1½ feet from the bottom of the trench and in each side of the trench. This will bring down enough of the sides of the trench to make a good enough barricade for the moment, but great care must be taken that while watching and protecting the barricade the enemy do not come overland and drop in behind the barricade, with disastrous results to the garrison.

Although the main defense of a line of trenches is infantry supported by artillery and machine gun fire, parties of bombers should be distributed throughout the front system of trenches. The best position is in the support trenches close to the main communication trenches, where they can make an immediate counter-attack should the enemy succeed in gaining a footing. A bombing trench back about 20 yards in the rear from which bombs may be thrown into the front trench, is a distinct advantage.

The bombs stored in the trench should be kept ready-fused and with detonators inserted. They must be distributed in a number of dry, enclosed, as nearly as bomb-proof depots as possible, established at frequent intervals along the trenches. A good type of grenade depot is one built in a “T” shaped trench, slightly off the main trench.