According to Wikipedia, there were various proposals -
this link is to the page dedicated to them.
The Southern Heights Light Railway (SHLR) was to have been a speculative London area suburban electric railway between Orpington, Kent and Sanderstead, Surrey. It was authorised in 1928 under the Light Railways Act 1896, but ultimately not constructed. The engineer was to have been Colonel Holman Fred Stephens, heavily involved in the promotion of light railways.
It appears that Colonel Stephens was brought in to promote an early scheme around 1900, known as the Orpington, Cudham, and Tatsfield Light Railway. Although most of the references in the Wikipedia article are outdated,
this is an up-to-date link to a series of blog posts about Biggin Hill, now on the University of Greenwich website, which delivers the following potted history of Biggin Hill railways:
Biggin Hill's major drawback has always been its poor transport links: one road in and one road out. Set on the top of the North Downs it was never going to be a candidate for a main line railway. It was this remoteness that resulted in the low land prices that enabled Frederick Dougal to offer his plots so cheaply. Even so, he realised that Biggin Hill would benefit greatly from a railway and supported the plans for the Tatsfield Light Railway which were developed in 1898.
By this date most of the accessible parts of the country were within easy reach of a railway, but some areas, especially in hilly regions, were prohibitively expensive to serve. The Light Railways Act of 1896 changed this, allowing lower cost railways to be built in return for lower maximum running speeds. The Tatsfield Light was to run from Orpington station via Green Street Green, Cudham and Biggin Hill to Tatsfield. Following a public enquiry it gained approval to proceed but the company was unable to raise the £70 000 required and the idea was quietly dropped.
This original plan came before Parliament on 22 July 1902, as per
Hansard:
Copy presented, of Order made by the Light Railway Commissioners, and modified and confirmed by the Board of Trade, authorising the construction of a light railway in the counties of Kent and Surrey from Orpington to Tatsfield (Orpington, Gudham, and Tatsfield Light Railway Order, 1902) [by Command]; to lie upon the Table.
After the collapse of the first scheme, Colonel Stephens did, as per the opening paragraph of the Wikipedia article, come back for a more ambitious scheme in the 1920s. T
his brief article is still up on the Chelsham Bus Garage website, which contains more details of the proposed route:
Plans were well under way in the 1920's between Colonel Holman Fred Stephens of Light Railway fame and the Southern Railway to construct a light railway from Orpington to Sanderstead with stations at :-
ORPINGTON
GREEN ST. GREEN for FARNBOROUGH
DOWNE & KESTON
CUDHAM & BIGGIN HILL
WESTERHAM HILL
TATSFIELD
CHELSHAM for WARLINGHAM
HAMSEY GREEN
MITCHLEY WOOD
SANDERSTEAD
The proposed passenger train service would have been operated by Electric trains with steam locomotives hauling the freight trains The timetable would have shown trains running in a circular service in each direction starting from Charing Cross and running via Waterloo East, London Bridge, Orpington, Green St. Green for Farnborough, Downe & Keston, Cudham & Biggin Hill, Westerham Hill, Tatsfield, Chelsham for Warlingham, Hamsey Green, Mitchley Wood, Sanderstead, Selsdon, Coombe Road, Woodside, Elmers End, Clock House, Lewisham, London Bridge, Waterloo East and Charing Cross. It is of interest to note that the section between Coombe Road, Woodside and Elmers End is now part of Croydon Tramlink. Agreement could not be reached and the plans were finally dropped in the early 1930's.
This was known as the Southern Heights Light Railway - a counterpoint to the Northern Heights railway I guess. Although there isn't a Jay Foreman video about this particular route, there is the next best thing - a video from Jago Hazzard:
Let me introduce you to the Colonel.
(Sorry, that's the fullest description of the video I can see, although it's slightly too early in the morning for me to be fully
compos mentis. I did think of the Northern Heights joke before finding the video, by the way, before anybody accuses me of stealing Mr Hazzard's wit.)
That neatly saves me from having to include any more research, so I guess I'll stop there. I suppose the shortest summary I can offer is that the settlement is not known as Biggin Hill for no reason, that Colonel Stephens was and is the only man ambitious enough to decide that trains and hills do mix, and that, for all the Colonel's effervescence, his first plan was quite a bit too early, and his second plan was slightly too late.
Incidentally the blogs about Biggin Hill's history are fascinating.