It is thought possible that Louis Renault began working on the idea as early as 21 December 1915, after a visit from Colonel J. B. E. Estienne. Estienne had drawn up plans for a tracked armoured vehicle based on the Holt caterpillar tractor, and, with permission from General Joffre, approached Renault as a possible manufacturer. Renault declined, saying that his company was operating at full capacity producing war materiel and that he had no experience of tracked vehicles. Estienne took his plans to the Schneider company, where they became France's first operational tank, the Schneider CA.