The first entry is always the pin's source. Overall confidence is a weighted average of how firmly each reference supports the start and end times used above; a reference counts half as much for every 180 days older than the newest.
French railway history sources (docrail.fr[2], Wikipedia’s[3] SNCF Class CC 7100 article) date the 331 km/h record run to March 28-29, 1955, crediting both the CC 7107 and BB 9004.
A French rail-history site corroborates the exact March 28-29, 1955 dates and locomotive identities for the record.[1]
The Wikipedia article on the CC 7100 class documents the March 1955 world speed record runs, including the 325 km/h and 331 km/h results on successive days, matching the "Quest for Speed" claim in the documentary.
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