The assembly positions from north to south of the various units were as follows:
| 3rd Heavy Tank Battalion | Ravine south-west of Montigny-Lengrain. |
| 12th Heavy Tank Battalion | Ravine north of Mortefontaine. |
| 11th Heavy Tank Battalion | Two Companies Ravine Longavesne and Lepine farm, 1 Company ravine 1 kilometre north of Soucy. |
| 4th Heavy Tank Battalion | Northern fringes of the forest of Villers-Cotterets south-east of Vivières. |
| 1st Heavy Tank Battalion | Maison Forestière, 200 metres north of the railway on the road from Villers to Soissons. |
| 10th Heavy Tank Battalion | Cross-roads south-east of the Cordeliers cross in Villers-Cotterets forest. |
| 1st Light Tank Battalion | Northern edge of Villers-Cotterets south-west of Vivières, ready to attack in the wake of the Moroccan Division. |
| 2nd Light Tank Battalion | Northern edge of forest south-west of Vivières ready to follow 2nd American Division. |
| 3rd Light Tank Battalion | St. George’s cross, ready to support either the 48th Division or the XIth Corps. |
Owing to the failure of the Military Transportation Authorities great delay was occasioned in the arrival of several units, and in some cases tanks had to be left behind. Generally speaking, detraining stations were not far enough forward; this resulted in the 1st and 3rd Light Battalions arriving late at their destinations.
During the night of July 17–18, the various units proceeded to their starting-points in rear of their respective lines of attack.
| 3rd Heavy Tank Battalion | } | St. Bandry—Saconin et Breuil—Vauxbuin. |
| 153rd Division | ||
| 11th Heavy Tank Battalion | } | Cutry—Missy aux Bois Ploisy. |
| 12th Heavy Tank Battalion | ||
| 1st American Division | ||
| 4th Heavy Tank Battalion | } | St. Pierre Aigle—Chaudun—Villemontoire. |
| Moroccan Division | ||
| 1st Heavy Tank Battalion | } | Chavigny—Beaurepaire Forest—Vierzy—Tigny. |
| 2nd American Division | ||
| 10th Heavy Tank Battalion | } | Longpont—Villers Helon—Le Plessier Huleu. |
| 38th and 48th Divisions |
The attack was launched at 4.35 a.m. in a slight fog which accentuated its surprise. There was no artillery bombardment. At 7.30 a.m., owing to the difficulties in communication and the rapidity of the advance, the Light Tank Battalions in Army reserve were placed at the disposal of the XXth and XXXth Corps in order to support the Divisions which had penetrated the deepest.
In this attack the enemy’s resistance was not unusually stubborn and the tanks and infantry advanced to a considerable depth without difficulty. Several tanks of the 12th Heavy Battalion fell out by the way, but those of the 10th succeeded beyond expectation in negotiating the difficult ground in the neighbourhood of Longpont. Of the Renault battalions only the first came into action, being launched at 7 p.m. in an attack on Vauxcastille ravin in which it succeeded in leading the infantry forward to a depth of three to four kilometres.
BATTLE OF SOISSONS
July 18th 1918.
Of the 324 tanks which were concentrated in the Tenth French Army Sector, 225 were engaged on July 18. Of these 102 became casualties, 62 being put out of action by artillery fire. In personnel the losses were about 25 per cent. of the effectives engaged.