Sir - I was interested to read of the proposed construction of a railway from Wau to Juba and Torit in Sudan, to be met by an extension of Ugandan Railways northwards to Torit (RG 12.05 p757).
This would of course create, albeit indirectly, a through rail link from Egypt to South Africa, something dreamed of for decades. However, such a journey would be interrupted by changes in track gauges. As is well known, whereas Egyptian railways are laid to standard gauge, railways in the Sudan are Cape gauge, as is the line southward from Dar-es-Salaam to Cape Town. As if that were not enough, the East African railways are built to metre gauge - only 67mm narrower than Cape gauge, but enough to prevent through running.
I should be interested to know what arrangements are envisaged to overcome this gauge difference. Gauge changing techniques are now widespread and efficient, though they usually require specially-built rolling stock. Whether the cost of this could be justified remains to be seen.
Presumably the long-term aim would be to convert the East African railways to Cape gauge, but that is a vast enterprise requiring funds on a heroic scale! Moreover, there would surely be a case for some north-south construction to avoid the general east-west trend of railways in those countries.
An alternative line through the Democratic Republic of Congo to the west of the Great Rift Valley reaches further north than Dar-es-Salaam, and is Cape gauge. But there is still a long distance between its railhead and Wau, and DR Congo is hardly the most politically stable region in central Africa, with railways still very un-refurbished.