Being at the end of the quadruple-track section of the Tonbridge cut-off line, in addition to forming the southern limit of the intensive commuter operation, the range of facilities on offer at Orpington were extensive. The goods yard of the original station, which merely consisted of a single northward-facing siding trailing off the ‘’up’’ line, was retained, but significantly enlarged. In total, eight sidings came into use on the ‘’up’’ side of the running lines: three of these trailed off at the same angle of ten degrees, as per the old layout, with one track of the trio passing through a single-track goods shed. The latter was a solidly-built brick structure, being two-storeys in height with a slated pitched roof, and was identical in appearance to the example which emerged at the rebuilt Chislehurst station. The goods yard was also host to a long line of coal staithes and a group of cattle pens (all descriptions thus far are later illustrated in diagram form). The ‘’down’’ side of the layout boasted an even greater range of tracks: three carriage sidings were laid alongside the bay line, virtually matching the latter in length. Furthermore, four southward-facing carriage sidings, of considerable size, came into use to the north of the platforms. The cutting at this point was accommodating nine parallel tracks: four were the aforementioned ‘’down’’ carriage sidings, another four formed the main line, and a single southward-facing siding was in evidence on the ‘’up’’ side, seemingly existing as an extension of the goods yard. Since the railway incurred on a public footpath here, a lattice footbridge of over 200-feet in length was erected across the tracks. Finally, although covered in a separate dedicated section, worthy of mention is the engine shed which was established here. This was a brick-built through affair, comprising a slated pitched roof and accommodating two northward-facing tracks. The depot complex was positioned on the ‘’down’’ side, upon a site situated in-between the bay platform sidings and the four southward-facing carriage sidings, and was intended to serve those tank engines – particularly classes ‘’H’’ and ‘’R’’ – which were deployed on commuter services. The engine shed layout was equipped with a 55-foot turntable, which could not only rotate those terminating tank engines of the suburban services, but was also large enough to accommodate the majority of the existing SE&CR tender engine fleet.

When built, signalling of the Tonbridge cut-off line was undertaken in-house by the SER, but later works saw the involvement of outside contractors. The 1881 opening of the Dunton Green to Westerham branch saw the emergence of Stevens & Sons’ signal boxes at both these stations, and the quadrupling works of the SE&CR used the services of Saxby & Farmer at a number of locations. The SE&CR took it upon itself to complete the signalling of the new Orpington layout, and the infrastructure employed very much reflected that this was a station on ex-SER territory. The layout was controlled from two mechanical cabins, ‘’A’’ and ‘’B’’ boxes, situated to the north and south of the platforms respectively. Evidently, SER standardisation was still in force, for both signal boxes were built to this company’s typical pre-1899 design, with pyramid-shaped slated roofs, complete with clapboard sides, and sash-style windows. ‘’B’’ box was situated within the fork created by the converging tracks beyond the southern ends of the platform surfaces. ‘’A’’ box was of considerable architectural note, but was by no means unique on the SE&CR system: it was an elongated all-timber two-storey high signal cabin suspended directly over one of the ‘’up’’ sidings upon a pair of brick walls, affording the signalmen an unrivalled and spectacular panorama across the entire layout. Signal boxes of this nature also came into use at Tonbridge and Paddock Wood.

Shortly before the Grouping, the SE&CR had proposed electrifying its suburban network by means of a fourth rail system rated at 1500 Volts. The company had been slower than its LB&SCR and LSWR counterparts in procuring any form of electric service on its network, simply because it did not have the financial means. On absorption into the Southern Railway, the entire ex-SE&CR network remained steam operated, but change was afoot. The newly-formed SR Board was dominated by members of the ex-LSWR, the largest of the constituent companies, and consequently, it was decided that this company’s 600 Volts D.C. third rail system would become the standard for future electrification projects. The SR was swift to electrify ex-SE&CR suburban lines, to provide a faster, more frequent, and more reliable service on those intensively used routes into the capital. Orpington has the distinction of being the first station on the whole of the Tonbridge cut-off line to be served by scheduled electric trains and, furthermore, marked the end point of the Eastern Section’s first electrified route. The initial lines to receive third rail were the former ‘’Chatham’’ metals emanating from Holborn Viaduct and Victoria: the routes converged at Herne Hill, and the very first bout of electrification was implemented along the line via Shortlands and Bromley South. Third rail was taken round the Bickley Loops to reach Orpington on the ex-SER cut-off line. Scheduled electric working to the station commenced from London on 12th July 1925. Electrification of the cut-off line’s northern half followed soon afterwards, and from 28th February 1926, scheduled electric trains were running from Orpington to Charing Cross, Cannon Street, and London Bridge. The SR’s service improvements instigated considerable housing development a mile north of Orpington, at Petts Wood, and consequently, a station was opened at the latter during July 1928.

Significant alterations were made at Orpington in conjunction with the aforementioned electrification. The engine shed was closed to steam traction and given over to the Permanent Way Department, with necessary track revisions being made to provide the depot with just a single trailing connection with the ‘’down’’ side bay line sidings. The station marked the end point of the electric system’s scope, and to accommodate terminating EMU stock, a huge carriage-cleaning shed was erected. This covered the four lengthy sidings which lied to the north of the station site, on the ‘’down’’ side of the running lines. The structure measured 1050-feet in length, becoming the largest carriage shed on the SR, and was constituted of a pitched-roof steel frame clad with asbestos. Each road was capable of accommodating thirty-two vehicles (of main line proportions), and third rail existed only for a short distance into the building for safety reasons. The carriage shed interrupted the course of the lengthy lattice public footbridge; the latter was subsequently modified to pass through the roof of the former. The four roads of the building were ultimately fed by a single track connected to the ‘’down’’ side bay line and sidings, and upon this short stretch of line existed a mechanical carriage washer – thus, any formation which arrived or departed the shed would receive a clean. Replacing the mess rooms of the closed engine shed were new crew rooms situated alongside the carriage washer, these being housed within a thin and lengthy single-storey brick-built pitched roof structure. Finally, the 1925 electrification had also seen third rail continue for a short way along the double-track section of route south of the station. This was to permit EMUs to perform platform changes at the southern end of the layout, avoiding the need to negotiate the busier crossovers which flanked ‘’A’’ box.

In January 1935, the SR completed the extension of third rail from Orpington to Sevenoaks, this being undertaken in conjunction with further electrification on the ‘’Chatham’’ main line between Bickley and Sevenoaks (Tubs Hill), via Swanley and the Bat & Ball branch. Scheduled electric services along these routes commenced on the 6th of that month. Running-in name boards with prefabricated concrete surrounds were installed at Orpington, a number of these being illuminated internally (SR ‘’Target’’ name signs had already been a feature of the site for a decade). Concrete bracket lampposts replaced the diamond-shaped examples of the SE&CR on the platform surfaces and in the former engine shed yard, and such posts were also used along the walkway to the carriage cleaning shed.

Track plan of electrified Southern Railway layout. © David Glasspool

26th September 2004

A London-bound view shows evidence of the 1992 platform lengthening to accommodate twelve-car "Networker" formations. Designed to tackle overcrowding, authorisation to run suburban services of this length was never eventually given under British Rail, in spite of the platform works at numerous stations. The scheme was revisited in 2013, when several stations on the North Kent routes and that between Charing Cross and Orpington had their platforms lengthened. In this latest case, twelve-car trains did commence. The "AD" code alongside the four-aspect colour lights denotes signal control from Ashford. © David Glasspool

26th September 2004

The station consists of eight platforms, half of which serve London-facing terminating tracks. The site immediately in front of the platform canopies in this Sevenoaks-bound view has, since 2008, been occupied by a huge footbridge. © David Glasspool

26th September 2004

Electronic destination displays arrived in 1999, replacing the television screens and digital clocks installed by Network SouthEast. Behind the blue palisade fencing on the far right is land which formerly made up part of the engine shed site, which closed as long ago as 1926. © David Glasspool