Complex sentence: The Réseau Breton 4-6-0 tank locomotives were a class of 12 metre gauge locomotives built in two batches by Franco-Belge, Raismes and SACM, Belfort for the Réseau Breton in France.
Split into simpler sentences: The Réseau Breton 4-6-0 tank locomotives were a class of metre gauge locomotives. The twelve class members were built in two batches by Franco-Belge, Raismes and SACM, Belfort for the Réseau Breton in France.