In the 30s the LMS on the West Coast Main Line, and the LNER on the East Coast Main Line used to battle for prestige, publicity, supremacy and speed records. Today, Saturday 28th June, we almost had a repeat, with the ECML and the WCML playing host to main line stream. Vintage Trains with the LMS Coronation Class 8P 4-6-2 no 46233 Duchess of Sutherland heading "The Midlander" Birmingham to Euston on the West Coast Main Line, and The Railway Touring company with BR Britannia Class 7MT 4-6-2 no 70013 Oliver Cromwell hauling "The East Riding" Kings Cross to Scarborough on the East Coast Main Line. A fine morning of mainline steam, but Ollie takes the crown easily for a faster noisier more robust performance.

https://www.youtube.com/watch?v=vqe6NV58wyk

Looks to me like a bad steam blow somewhere on Cromwell's starboard cylinder. Have there been any comments on what that might be?