Howrah-Chennai Mail is a very important superfast mail train of Indian railways connecting two metropolitan cities of India, Kolkata and Chennai, and Bhubhaneswar, capital of Odisha. It made its inaugural run on 15 August 1900,(source Indian Railinfo.com time table) which makes it one of the oldest running trains on Indian Railways. It rightly deserves to be categorised as one of the classic trains of India,having run and served the country on this route from very early days of Indian Railways through all its stages of development(over 112 years),first hauled by steam engines, including the WP class engines, then by diesel, and now by electric locomotives. It was the first passenger train to be dieselised on South Eastern Railway, in 1964/65. Till the introduction of the Coromandal Express in the mid seventies, it was the main and fastest train link between Howrah and Chennai (then Madras) with much less number of halts. Presently, this train is the second most important train on the Howrah-Chennai main line after the faster Coromandal Express. It covers 1661 Kilometers at an average speed of 59 km/h. This train has Ac first, Ac two tier, AC three tier, Sleeper, General classes. A Pantry car facility is available in it. All its classes except General require prior reservation; General class coaches of this train are usually crowded, and can be boarded with a general daily ticket.Tatkal scheme is available in this train. It shares rakes with Coromandal Express. Important stations through which it passes are Kharagpur, Balasore, Cuttack, Bhubaneswar, Berhampur, Visakhapatnam, Rajahmundry, Vijayawada. 12839 Howrah Chennai Mail leaves Howrah at 11:45 P.M. everyday and reaches Chennai Central on second day early morning at 3:50 A.M. 12840 Chennai Howrah Mail leaves Chennai Central at 11:40 P.M. everyday and reaches Howrah at 4:10 A.M. second day. Throughout its journey it is hauled by WAP 4 class electric locomotives of Indian railways.