There is almost no wind in the Mauritanian desert as the about two-kilometre-long empty train from the port of Nouadhibou to the ore mine near Zouérate approaches Pk 404 between Ben Amira and Choum after 9.30 am. Above the train, which is traveling at a good 50 km/h, a clearly visible cloud of diesel exhaust fumes, the finest swirls of desert sand and powdery remnants of iron ore has formed. Train V5 (Vide # 5) is more than halfway through its 652-kilometer journey after the crew change in Tmeimichat at PK 318.