Here we concentrate on the information about the railway stations on this route.
In 1935, distances are given in miles:
1935 | Miles | Miles from | |
previous | |||
Nandyal | 0 | ||
Gazulapalli | 9 | 9 | |
Chelama | 20 | 11 | |
Diguvametta | 35 | 15 | |
Giddalur | 42 | 7 |
In 1976, the route is still metre gauge but distances are in kilometres:
1976 | Km | Km from | |
previous | |||
Nandyal | 0 | ||
Gazulapalli | 14 | 14 | |
Chelama | 32 | 18 | |
Diguvametta | 57 | 25 | |
Giddalur | 68 | 11 | |
This matches the miles from 1935. | |||
After conversion to BG, these are the distances in kilometres:
2021 | Km | Km from | |
previous | |||
Nandyal | 0 | ||
Gazulapalli | 14.6 | 14.6 | |
Chelama* | 25.4 | 10.8 | |
Diguvametta | 42.1 | 16.7 | |
Giddalur | 53.6 | 11.5 | |
* At new location |
Note that Basavapuram and Bogara stations were not listed in the timetables in 1935 and later.
Comparing 1976 and 2021:
Distance from Nandyal to Gazulapalli practically same. (2021 data is more accurate).
Distance from Gazulapalli to Chelama* is 10.8 km vs 18 km to old Chelama.
Distance from Chelama* to Diguvametta is 16.7 km vs 25 km from Old Chelama
Distance from Diguvametta to Giddalur is 11.5 km is practically the same.
Thus, in the entire Nandyal-Giddalur section there is a saving of about 14.4 km.
Many of the curves have been removed.
The line is BG and electrified, but not doubled yet.
A sketch of the new and old alignments (based on the Great Indian Railway Atlas, 2015):

I have tried to fit in the most relevant items.
Dorabavi viaduct (about 1 km) between Chelama (old) and Bogara, near the latter.
Bogada tunnel on BG, about 1.6 km long, between Chelama (new) and Diguvametta.
Chelama tunnel on BG , about 0.28 km long, a little west of Chelama (new).
The old and new alignments diverge west of Gazulapalli, and east of Diguvametta. However, the pillars of the Dorabavi viaduct can be seen to the north just west of the Bogada tunnel on the BG line.
Here is a video taken from the brake van of a west-bound goods train starting from a point near Diguvametta, passing through the Bogada tunnel, Chelama (new) station and the shorter Chelama tunnel. It ends short of Gazulapalli. From around 4.15 to 4.50 (just after the tunnel) you can see the pillars of the viaduct. Also note the musical accompaniment.
Enjoy this:
Will wrap up with some more details in the next instalment.