The tracks are 950 mm apart, a size unique to the Italians. According to the 1952 200 Pagine sull' Eritrea, a book showing off the commercial wares of Eritrea, the line had 29 stone bridges, two metal ones, and 39 tunnels while 11 Littorinas and 23 steam and diesel locomotives provided its pulling power.
After the time I was there but surely part of the overall story, the Ethiopians dismantled the route in 1976 when it became apparent that they could not keep it running due to Eritrea's war for independence. Since Eritrea achieved independence in 1991, the Eritreans have been slowly rebuilding the route. They hope to reach Asmara in 2002.
For many more detailed specifications on this railroad and it's rolling stock see Ralph R. Reinhold's Eritrean Railway and Ropeway.