In 1870 the first railway line between Estonia and St. Petersburg was opened and the post wagons 39 and 40 started running on October 24 between ГАТЧИНА (Gatchina) and БАЛТИЙСКИЙ ПОРТЪ (Baltiski Port, Paldiski) and vice versa via Narva, Taps, Revel and Kegel .
Literature, articles in Dutch, about: railway post in Estonia 1870-1918: lines, stations, postmarks:
Treinpost in Estland (1870-1918) / Alexander Epstein
In: HBG 2005 ; 46. – p. 46-62 (part 1) Download as pdf
Treinpost in Estland (1870-1918), deel 2 / Alexander Epstein
In: HBG 2005 ; 47. – p. 28-39 (part 2) Download as pdf