The armoury, which belongs to the 17th century, is a protected monument.
It is a rectangular stricture with a pyramid shape roof and one among the eight armouries of the same period in Srirangapatna town.
Similar armouries are also found in the Manjrabad fort in Sakleshpur.
The works on the bridges across the River Cauvery for the doubling of the track has been delayed since almost a decade due to the presence of the armoury.
Now, it has been decided to push the whole structure on railings, with the help of a French company, 50 metre to the North.
The State Archeology department has issued a no-objection certificate for the process, according to Assistant Archeologist N L Gowda.
Earlier, there had been two more proposals to shift the armoury.
One was to cut the monument into one metre cubes and reconstruct it at a farther place.
The other was to completely dismantle and reconstruct it completely.
Finally, it has been decided to retain the original structure as a whole and move it along with its foundation, by digging a trench and laying railings to move it.