In the 1930s the City’s Engineer’s Department built this substation in warm red brick laid in Dutch-bond, replacing an earlier building. It also served the tram net-work that ran from town to Zoo Lake and Rosebank between 1906 and 1961. Its transformation by studioMAS and JCAF in 2018 was achieved by subtle means and with only two significant additions: a glass box linking two buildings, and a dramatic steel portico that rises from the tracks on which trans were once guided into it.  Johannesburg Heritage Foundation. logo.