The recent decision of the BBC to ditch shortwave for North America and the Pacific reminded me of some documents I unearthed a few years ago in the Public Record Office at Kew in London. At the time I was supposed to be writing a Ph.D thesis on a completely unrelated topic, but my talent for being sidetracked by more interesting subjects contributed in large part to the fact that the thesis remains unfinished.
Anyway, originally in the early and mid 1960s, when Ascension was first chosen as a relay site, it seems that various senior people in the BBC External Services had already decided that shortwave was a thing of the past, and the original correspondence between them and the Foreign Office (which would be paying the bills) assumed that Ascension Island would be using mediumwave. Yes, mediumwave.
Of course, the island's position in the middle of a rather wide ocean meant that they would need quite a lot of power, and 20 megawatts was the figure being worked on. That was the actual transmitter power, not ERP, and would be fed into a high-gain antenna beamed northeast towards West Africa. The official concern was to ensure coverage for listeners with new-fangled transistor radios in countries which were gaining independence around that time, especially Nigeria and Ghana. In order to provide the huge amount of electricity needed by this setup, a floating nuclear power plant would be manufactured in the UK, shipped out with enough fuel rods to last a decade or two, and moored off the coast of Ascension.
Needless to say, saner minds eventually prevailed after pointing out the huge technical and security problems with this idea, which if ever realized would only provide mediocre night-time coverage with a single programming stream, and, according to projections, would only cover areas very close to the West African coast. Also, it would have been very easy for a hostile government to jam. So in the end it was decided that perhaps shortwave was not such a bad thing after all, and first two, then four, and in the 1990s six 250 kw. units were installed on Ascension. Another advantage, of course, was that this also permitted coverage of Central and Southern Africa, South America and the Caribbean.
At about the same time it was decided that the BBC also needed a stronger signal in East Africa. It did at one point have a MW facility in Somaliland, which I believe was later moved to Masirah Island in Oman, but the site selected to replace it for coverage of Africa was the island of Aldabra in the Indian Ocean. Mediumwave was also chosen, but this time it was felt that a mere 10 megawatts of transmitter power would probably be adequate, although the nuclear power option would also be necessary. In this case the plan was metaphorically torpedoed not only by the saner minds at the BBC, but also by ecological worries about the rare Aldabra turtle whose survival would have been jeopardized by any kind of relay station, whether on mediumwave or shortwave. Of course, eventually the seeds planted in the 1960s germinated in the mid 80s with the Indian Ocean Relay Station in the Seychelles.