 With the vesting of the Watford and Rickmansworth Railway in the London, Midland and Scottish Railway (LMSR) in 1923, the nine joint LNWR/LER electric tube cars became known as "watercress trains" due to the volume of watercress gathered in the Chess Valley that the trains often carried in their luggage compartments.The stock was finally withdrawn in 1939 with the introduction of emergency war timetables and replaced with main line size electric stock.Notwithstanding the introduction of electric services, the Rickmansworth branch suffered in the face of the more direct services to London provided by the Metropolitan.