Largest UK locomotive

[matchmaker]

I know we're in danger of drifting but 40s were really just 10203 without any real mechanical improvements. I believe EE offered to uprate them to 2400hp in later builds but BR declined as wanted reliability. To be fair, they may have been big and heavy but we're pretty bulletproof. I understand it was rare for one to fail.

40s were also notorious for having a handbrake that wouldn't hold them on any remotely serious gradient - wheel scotches had to be used.

 

[ac6000cw]

There was a performance report D200's vs kettles, didn't bode well for the 40's if I remember.

I think the Eastern Region regarded them as no better than a Britannia and inferior to a decent ex-LNER Pacific on passenger trains. They wanted something with enough power to seriously accelerate the ECML services, hence declining to take any more D200s (which made more available to the LMR) and twisting the arm of BR/BTC to buy the Deltics.

Richard Scott said:
I know we're in danger of drifting but 40s were really just 10203 without any real mechanical improvements. I believe EE offered to uprate them to 2400hp in later builds but BR declined as wanted reliability. To be fair, they may have been big and heavy but we're pretty bulletproof. I understand it was rare for one to fail.

I think EE's previous experience in building diesel-electric locos and applying the 'keep it simple' principle is what made their locos of the late 50's/early 60's reliable (and also keeping as much as possible 'in house', using diesel engines and electrical equipment of their own design and manufacture).