Initially the smoke-filled stations and carriages did not deter passengers and the ventilation was later improved by making an opening in the tunnel between Gower Street and King's Cross and removing glazing in the station roofs.
I starten afskrækkede de røgfyldte stationer og vogne ikke passagerer, og ventilationen blev senere forbedret ved at lave en åbning i tunnelen mellem Gower Street og King's Cross og fjerne ruderne i stationslofterne.