What is the top speed of the Class 37 locomotive?

The Enduring Power of the Class 37: More Than Just Speed

The British Rail Class 37 locomotive, affectionately known by some as “Tractors” due to their rugged dependability, is a workhorse of the UK railway network. While sleek high-speed trains capture the headlines, the Class 37’s enduring legacy is built on its raw power and versatility, making it a cornerstone of freight and passenger operations for decades. But what about its speed? How fast can these locomotives actually go?

The official top speed of a standard Class 37 is 90 mph (140 km/h). This figure, however, isn’t the whole story. A significant number of Class 37 locomotives were later re-geared, specifically by modifying their CP7 bogies. This alteration, while potentially impacting acceleration slightly, prioritized hauling heavier loads, which was crucial for many of their operational roles. This re-gearing reduced the maximum speed to 80 mph (130 km/h).

It’s important to understand that speed is just one piece of the puzzle when evaluating a locomotive’s capabilities. The Class 37 is less about breakneck speed and more about brute strength. Powered by an English Electric 12CSVT engine producing 1,750 bhp (1,305 kW), the locomotive boasts a maximum tractive effort of 55,500 lbf (247 kN). This impressive force allows it to pull heavy freight trains and navigate challenging gradients with relative ease. Further emphasizing its hauling capabilities is its continuous tractive effort of 35,000 lbf (156 kN) at 13.6 mph (22 km/h), highlighting its ability to maintain pulling power even at lower speeds.

Beyond its pulling prowess, the Class 37 is equipped with a robust braking system. This system is crucial for controlling heavy trains, especially when descending inclines. The brake system can deliver a significant 50 long tons-force (498 kN) of braking force, ensuring safe and reliable operation under demanding conditions.

In conclusion, while the Class 37’s top speed of either 90 mph or 80 mph might not rival modern high-speed trains, it’s the combination of power, tractive effort, and a reliable braking system that has cemented its place in railway history. The Class 37 is a testament to the fact that sometimes, it’s not just about how fast you go, but how much you can haul and how reliably you can do it. Its legacy continues to be written on the rails, a powerful reminder of a bygone era of British railway engineering.