History of Laying of tracks in Mumbai Western Division:
Churchgate - Surat (Down & Up line)
• Surat to Valsad in 1861
• Valsad to Grant Road in 1864
• Grant Road...
more...

to Charni Road in 1868
• Charni Road to Marine Lines in 1869
• Marine Lines to Church Gate in 1870
• Churchgate to Colaba in 1896 (Closed on 31.12.1930)
Churchgate - Borivali (Down & Up Local line)
• Borivali to Grant Road in 1954
• Grant Road to Churchgate in 1974
Mumbai Central - Borivali (Fifth line)
• Mumbai Central to Bandra Terminus in 1993
• Santacruz to Borivali in 2002
Quadrupling of section between Borivali - Virar
• Vasai road – Virar in 2004
• Borivali - Vasai road in 2007
Udhna - Jalgaon (Single Line Section)
• Udhna to Vyara in 1898
• Vyara to Nardana in 1899
• Nardana to Jalgaon in 1900
• Udhna Bye-Pass line in 2004
Bilimora - Waghai (Narrow Gauge)
• Bilimora – Waghai in 1937
Source: One of the PDF in Google.(Picture Attached)