The shots, taken by drone, show the 70 metre-high section of embankment at Eden Brows near Armathwaite in Cumbria which gave way and was repaired with 226 steel piles.
The track reopened last March but work will continue until next spring to pack vast boulders into the bank of the River Eden. The 20,000-tonne “rock armour” is designed to guard against erosion caused by swollen flows in the event of further floods.
Network Rail, which carried out the work, said that even if the ground gave way there in the future, the railway would not.
The job was the biggest ever undertaken by the company.
Martin Frobisher, managing director of its London North Western route, said: “It’s not until you see the aerial shots that you appreciate the sheer scale of this repair. The landscape is as rugged as it is beautiful. The Victorians certainly did choose a wonderful spot to build a railway.”
The Settle to Carlisle line, opened in 1876, attracts tourists from around the world. It is also seen as a key freight route.
It survived an earlier threat in the 1980s when British Rail deemed it uneconomic. Officials were eventually defeated by local pressure groups, supported by the then transport secretary, Michael Portillo.
Mark Rand, of the Friends of Settle Carlisle Line, said: “Eden Brows suffered a massive landslip when the line was being built in the 1870s. History repeated itself in 2016.
“That work of this scale has been done in such fine style underlines the strategic importance, and tremendous potential of this line.”