(2) _An attack against trenches without an artillery barrage_ (see diagram 14).--One tank in advance, followed at a distance of 100 to 150 yards by two others at 200 to 300 yards’ interval, and one tank in support. The infantry should be disposed of as before. The advanced tank to a certain extent replaces the artillery barrage and acts as a scout to the two behind, which form part of the infantry firing line.
(3) _The field warfare attack_ (see diagram 15).--In the field attack the action of the tanks must be adapted to circumstances. This action falls under three headings:
(i) Moving in front of the infantry firing line.
(ii) Moving with the infantry firing line.
(iii) Moving behind the infantry firing line.
When moving with the infantry firing line, which will generally be the most suitable formation to adopt, tank sections should form mobile strong points or bastions, which will not only reduce the number of infantry required for the firing line, but which will be able to bring oblique and cross fire to bear in front of the advancing infantry. In order to reduce the human target as much as possible without reducing fire effect, Lewis-gun sections should freely be used to cover by fire the intervals between tank sections. These Lewis-gun sections should be followed by rifle sections which, directly opposition is broken down by the tanks and the Lewis gunners, should move rapidly forward several hundred yards in front of the tank and infantry firing line, forming to it a protective screen of sharpshooters. This formation should then be maintained until the rifle sections get hung up, when the tank and Lewis-gun firing line should pass through them to renew the attack, the rifle sections forming up in support in rear. Curiously enough this formation resembles very closely that generally adopted by the Roman Velites and Hastati (riflemen), Principes (Lewis gunners), Triarii (tanks), and Napoleon’s Light Infantry (riflemen), Infantry of the Line (Lewis gunners), Old Guard and Heavy Cavalry (tanks).
As an infantry attack depends on the following principles--the objective, the offensive, security, mass, economy of force, surprise, movement, and co-operation--so does a tank attack. The tank must know what it is after, it must act vigorously, it must be protected by artillery just like infantry, it must attack in mass, that is in strength and numbers, but not, necessarily, all in one place; it must surprise the enemy, move as rapidly as it can, and work hand in glove with the other arms. On the application of these principles to the conditions which will be met with will depend the success or failure of the tank attack.