Much before even a brick was laid at the site that is now New Delhi, the architects of the new city had to fight an interesting bureaucratic battle with the railways to secure two crucial things, without which the new Capital would not have been a reality.
Firstly, they needed a host of
new lines to be laid on the rocky ridges of Raisina Hill to transport men and material for 20 years. And secondly, they needed the railways to remove the crucial Delhi-Agra Chord line, which then ran across the site earmarked for the hexagonal All-India War Memorial (India Gate), Kingsway (which later became Rajpath), and much of the present Lutyens' Bunglow Zone area.
The first was an engineering feat considering the rocky terrain, and it was achieved over a long period as construction work expanded. A special railway line, called the 'Imperial Delhi Railway', was built to transport construction material and workers. A circular track ran around the entire length of the Council House (now Parliament House). But it was the second task that proved to be a bit of a stumbling block in the initial years.
Correspondences between the architects and officials of East Indian Railway Board reveal that the railway brass came up with every reason, technical or otherwise, they could find to keep the Delhi-Agra Chord line where it was. 
The Delhi Lines Committee set up after World War I to advise the government on the pace and nature of growth of the railways in the new Capital, proposed a grand scheme to this effect, suggesting even the location of a new railway station for the city.
The Board in its reply said while it "generally agreed" with the scheme proposed, it favoured a "gradual" pace of investment "based on requirement and experience" and that it would be "necessary to modify the scheme from time to time".
The prevailing theory was that since (Old) Delhi already worked as a busy junction in the area, hosting four zonal railways, the new capital city did not need to overhaul the whole network around it.
"The line was of course realigned after a few years, but initially the Board appeared a bit cautious in its response to the whole plan," said Vinoo Narain Mathur, former Member Traffic, Indian Railways, and author of Bridges, Buildings and Black Beauties of Northern Railway.
The Minto and Hardinge rail bridges came up for this realigned line, which was shifted along Yamuna and was open in 1924. It stays that way even today.