How Did Steam Engine Drivers Know Their Speed?

Did British steam locomotives have speedometers? For over a century, most British Railways and GWR engines carried no speed gauge at all. Instead, steam engine drivers had to calculate speed using a stopwatch, track mileposts, and mental arithmetic. This railway engineering documentary investigates how steam locomotive speed was actually measured before modern instruments. We cover everything from the 1904 City of Truro 100 mph run on Wellington Bank to early mechanical instruments like the rare story of the French Flaman speed recorder ("le mouchard") and William Stroudley’s water-gauge speed indicator. We also examine why Britain resisted cab speedometers until the catastrophic 1955 Milton train derailment forced a regulatory overhaul. Support the Channel: Support future rail engineering documentaries on Ko-Fi (every supporter is credited in upcoming videos): https://ko-fi.com/marcflint Follow on X: https://x.com/MarcFlintYT Chapters & Topics Covered: 00:00 - The Mystery of the Missing Speedometer 01:15 - City of Truro & The 102 MPH Stopwatch Dispute (1904) 03:10 - Mileposts, Quarter Posts, and Driver Calculations 05:00 - The French Flaman Speed Recorder & Paper Rolls 06:45 - William Stroudley's 1874 Water Gauge 08:20 - The Milton Derailment (1955) & Langley Report -- DEUTSCHE ZUSAMMENFASSUNG -- Hatten britische Dampflokomotiven Tachometer? Über ein Jahrhundert lang besaßen die meisten Lokomotiven von British Railways und der GWR überhaupt keinen Geschwindigkeitsmesser. Lokführer mussten das Tempo anhand von Stoppuhren, Meilensteinen und Kopfrechnen ermitteln. Diese Doku beleuchtet die historische Messtechnik vor modernen Instrumenten: von der 100-mph-Rekordfahrt der „City of Truro“ (1904) über frühe mechanische Geräte wie den französischen Flaman-Fahrtenschreiber („le mouchard“) bis hin zu William Stroudleys Wasserstandsmesser. Außerdem klären wir, warum Großbritannien erst nach der folgenschweren Entgleisung von Milton 1955 flächendeckend Führerstand-Tachometer einführte. -- RÉSUMÉ EN FRANÇAIS -- Les locomotives à vapeur britanniques avaient-elles des compteurs de vitesse ? Pendant plus d'un siècle, la plupart des motrices de British Railways et du GWR ne disposaient d'aucun indicateur. Les mécaniciens devaient estimer l'allure du train à l'aide d'un chronomètre, des bornes milliaires et du calcul mental. Ce documentaire examine la mesure de la vitesse à l'ère de la vapeur : du record à 100 mph de la « City of Truro » en 1904 aux premiers instruments mécaniques comme le célèbre indicateur Flaman (« le mouchard ») ou le système hydraulique de Stroudley. Nous retraçons également pourquoi la Grande-Bretagne a attendu le grave déraillement de Milton en 1955 pour rendre le tachymètre obligatoire. Reference Archive & Sources: Railway Museum: Loco Speedometers & History: https://blog.railwaymuseum.org.uk/loc... The Flaman Speed Recorder: https://blog.railwaymuseum.org.uk/my-... Ministry of Transport Milton Report (1955): https://www.railwaysarchive.co.uk/doc... Locomotive Engine Driving (Reynolds): https://archive.org/details/locomotiv... British Railways Speedometer Fitting History: https://www.rmweb.co.uk/topic/137062-... Recommended Reading (Amazon Affiliate Links): How a Steam Locomotive Works (Dominic Wells): https://link.amazon/B0dtWc78C (#ad) How Steam Locomotives Really Work (Semmens & Goldfinch): https://link.amazon/B01LfoLUm (#ad) The Engine Driver's Manual (Brian Topping): https://link.amazon/B0azM0biy (#ad) How to Own a Steam Engine (David Bramhall): https://link.amazon/B0aowC43g (#ad) Video Archive Credits: 3440 City of Truro at 100 Documentary (Wonderful Railway Videos) City Of Truro 2005 (Neil Mundy) 45305 + 70013 Oliver Cromwell at Clinnick Viaduct (Classic Traction) Deltic Diesel Powered Train 1962 (British Pathé)