Automatische Übersetzung. Originaltext in: EN - Original anzeigen The Pacific 231 PO 3566, rebuilt by the renowned steam specialist André Chapelon, was transferred in 1931 to the Compagnie des chemins de fer de l’Est network to undergo a series of trials, which proved to be highly successful.

The operational condition and performance of the 231 PO 3701 - 3721 and 231 PO 3722 - 3731 series ultimately convinced the management of the Eastern Railway to place orders in May and October 1934 for 10 and 13 locomotives respectively, all built to the "Chapelon second-type" standard.

The rebuilding work, carried out on former 231 PO 3501 - 3590 locomotives, was undertaken at the Tours workshops of the Compagnie du chemin de fer de Paris à Orléans between April and October 1935.

Following completion, these locomotives were registered 231 Est 051 - 073. / Quellen: https://fr.wikipedia.org/wiki/231_Est_051_à_073