One fact, often ignored when considering rival claims, is that Gresley and the LNER had just one serious attempt at the record, which was far from a perfect run with a 15 mph permanent way check just north of Grantham. Despite this a record was set. Gresley planned another attempt in September 1939, but was prevented by the outbreak of World War II. Prior to the record run on 3 July 1938, it was calculated that was possible, and Driver Duddington and LNER Inspector Sid Jenkins both said they might well have achieved this figure had they not had to slow for the Essendine junctions.