When South Africa plunged into a recurring series of blackouts earlier this year, we posed the question: what is Metrorail – 100% dependent upon electricity but without a single diesel on its roster – going to do about it?  Will backup diesel locomotives be bought?

One memorable day in 2006, we recalled, no suburban trains whatever ran in Cape Town, thanks to a complete electricity shutdown. It came pretty close to a reprise on 1 February 2008, when a massive power failure not only stranded hapless people in lifts across a jammed city without traffic lights, but left tourists hanging in mid-air on the Table Mountain cableway.  On this occasion, fortunately, the trains had already gone to bed - for their customary (these days) early night.