Most powerful UK passenger / test consist

[randyrippley]

Back in the late 70's I saw a test train at Galgate on the WCML consisting of two APT-P power cars, led by one of the HST prototype power cars with four test cars. As far as I could tell all three were under power.
Hard to think of a more powerful test rig

I once found film on youtube of it going through Preston, but never been able to locate it again

 

[Grannyjoans]

Why didn't Kestral get beyond prototype stage ? A large fleet of these would have been very useful on both heavy freight and express passenger. 4000hp+ diesels are what was really needed.

 

[JohnMcL7]

Why didn't Kestral get beyond prototype stage ? A large fleet of these would have been very useful on both heavy freight and express passenger. 4000hp+ diesels are what was really needed.

I believe the main issue was it was too heavy and over the 20 ton axle loading limit BR had set, they did attempt to reduce the weight but also reduced the power.

 

[randyrippley]

Why didn't Kestral get beyond prototype stage ? A large fleet of these would have been very useful on both heavy freight and express passenger. 4000hp+ diesels are what was really needed.

It was too heavy and so had major route restrictions even after swapping the bogies for those off a 47.
More importantly Sulzer lost interest in locomotive diesels and sold the intellectual rights to the LV v-engine range to GEC.
The Ruston-Paxman engines in the class 56 and 58 are said to owe more to Sulzer technology than EE. You could say the 56 and 58 ARE the productionised version of Kestrel