The locomotive built by skipping the rules to beat the clock

Wars & Conflicts · Published 9 October 2026 · Updated 25 October 2026 Swipe more like this →

In short: In 1956, British Railways faced a crisis: they needed powerful new locomotives immediately to support a massive electrification scheme. To bypass standard competitive tendering and secure the fastest possible delivery, officials made a controversial executive decision to hand-pick a builder, sparking a corporate protest and a logistical marathon.

The British Rail Class 33, known as 'Cromptons,' were born from a logistical bottleneck. The Southern Region required a locomotive that could handle heavy summer tourist traffic without the need for steam heating, as carriage heating would be unnecessary in the warmer months. To achieve this, engineers took a 1,160 bhp Type 2 locomotive and swapped its 6-cylinder engine for a larger 8-cylinder version, boosting output to 1,550 bhp. This made them the most powerful Bo-Bo diesel locomotives in the British Rail fleet at the time.

The procurement process was fraught with tension. In December 1956, the British Transport Commission (BTC) decided to approach English Electric directly for the build. This move bypassed the standard competitive tendering policy, a decision justified by the urgent need for speed. However, the move backfired politically; Vickers-Armstrong, the manufacturer of the Sulzer engines used in the UK, filed a formal protest against the bypass. The BTC eventually relented and put the process out to tender in February 1957.

Despite the controversy, the Birmingham Railway Carriage and Wagon Company (BRCW) won the contract. The project was plagued by cascading delays. The first batch of 45 locomotives, intended to be in service by June 1959, saw its final delivery pushed back by 14 months. These delays were so significant that they forced the postponement of steam locomotive phase-outs and delayed the closure of the Ramsgate Motive Power Depot. Ultimately, 98 of these locomotives were built between 1960 and 1962 to bridge the gap during the Kent Coast electrification scheme.

The Class 33 serves as a case study in industrial trade-offs. By removing the unreliable steam heating boiler to gain power and reliability, the Southern Region optimized for specific seasonal demands. It highlights a recurring theme in infrastructure: the friction between bureaucratic protocol and the practical necessity of meeting looming deadlines.

General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.

Intellect Plus is a visual educational discovery platform for exploring fascinating facts and ideas. Brain Food, Not Brain Rot. What is Intellect Plus?

Related

• The diesel locomotive that became Britain's railway workhorse for over half a century
• How Britain’s InterCity 125 became the world’s fastest diesel train on a budget
• Britain's stopgap diesel train outlived the futuristic project it was meant to cover
• The British railway locomotive that survived by being the only one left.
• The versatile bi-mode locomotive that solved the Southern Region's electrification dilemma
• The 225 Rangers who scaled the cliffs of Pointe du Hoc
• The high-pitched engines that powered the Allied landings in WWII
• A division built from scratch, destroyed, and rebuilt through the Western Front
• How one British officer used fake armies to fool the Nazi high command
• The high-speed successor designed to fix the Typhoon's fatal flaws
• The meteorologist who promised sunshine for the D-Day invasion
• The strategist deciphering the legacy of her famous grandfather

More in D-Day & Normandy · More in Wars & Conflicts · Latest · A–Z · All topics