The Bexleyheath Line leaves the North Kent Line immediately on the Down side of Blackheath railway station and travels due east for 8 miles (13 km) to a junction with the same line south of Slade Green. There was a line to the south (the Dartford Loop Line) but, in spite of public pressure in the 1880s, the South Eastern Railway (SER) refused to build a line to serve the area between the two lines.
It was therefore another company – the Bexley Heath Railway (BHR), led by railway engineer Alfred Bean (owner of Danson House) – who put forward a scheme for this line, securing the necessary Act of Parliament in 1883. But it took a further twelve years for the scheme to be realised, and it was not until 1 May 1895 that the Bexleyheath Line was finally opened. The BHR soon went into bankruptcy, and the SER were forced to take over the line.
There were originally six stations on the line; one was added subsequently with the growth of the suburban area served by the line.
The stations, starting at the North Kent line, and with notable features listed underneath, are:
- — junction with the North Kent Line east of Blackheath
- — near Kidbrooke Tunnel (c. 400 yd / 360 m)
- Eltham, which was built to replace both:
- — opened in 1936
- — triangular junction with the North Kent Line linking trains with Slade Green carriage sidings and Dartford
Most trains using the line call at all stations (apart from weekday busy periods) and terminate at Dartford.