British Rail Class 37

The British Rail Class 37 is a diesel-electric locomotive. It is also known as the English Electric Type 3. The Class was ordered as part of the British Rail modernisation plan.
The Class 37 became a familiar sight on many parts of the British Rail network. They were on Inter-City services in East Anglia and within Scotland. They also performed well on secondary and inter-regional services for many years. The Class 37 is known by railway enthusiasts as a "Tractor". This nickname came from the similarity of the sound of the locomotive.