🚂 The Mighty Little Class 03 Shunter 🚂 Sometimes the smallest locomotives leave the biggest impression — and the British Rail Class 03 is a perfect example. Built between 1957 and 1962, these compact 0-6-0 diesel-mechanical shunters became the unsung heroes of Britain’s railway yards, quietly working away behind the scenes. With just 204 horsepower, they were never designed for speed or glamour. Instead, their strengths were simplicity, reliability, and incredible agility — perfect for docks,