British Steam Railways & Locomotives: Pocket Encyclopaedia by O. S. Nock is a compact illustrated reference book that surveys the development of British steam railways and locomotive design.

Written by railway historian O. S. Nock, it combines technical explanations with photographs and diagrams to cover key locomotive classes, railway engineering developments, and the evolution of steam traction in Britain.

It is designed as a “pocket encyclopaedia,” making it a concise, accessible guide for enthusiasts rather than an in-depth academic history.