British Rail Class 73: Difference between revisions

Although successful this system did require considerable extra cost, and maintenance, and still limited freight operations with the new locomotives to those goods yards fitted with the catenary. Something more versatile was needed. Development and advances in both electric locomotive and diesel engine design in the early 1960s resulted in the Southern Region engineers beginning to consider the possibility of a [[electro-diesel locomotive|combined electric and diesel locomotive]]. The requirement was for an electric locomotive with a similar power when using the electrified third rail to the already successful Type 3 Birmingham Railway Carriage and Wagon (BRCW) built diesel locomotives (later [[British Rail Class 33|Class 33]]) then entering service on the Southern. This would be supported by adding a small diesel, engine powerful enough to move reasonable freight loads at slow speed within goods yards. The new locomotive design would also need retractable third rail [[contact shoe|pick up shoes]]. This was for two reasons: the first was safety in connection with track relaying jobs, avoiding the problem of bridging a gap and energising a dead section of third rail, and electrocuting track workers who might be in contact with the dead third rail section. The second was to allow locomotives under diesel power to move off and back onto third rail areas without risk of damaging "fixed" third rail pick up shoes.

 

 

== Accidents and incidents ==