South Western Main Line

The South Western Main Line is a railway line between London Waterloo and Weymouth on the Dorset coast, in the south of England. It is a major railway which serves many important commuter areas, as well as the major settlements of Southampton and Bournemouth. It runs through Greater London, Surrey, Hampshire and Dorset.

It has many branches, including the lines to Reading, Dorking, Guildford, Portsmouth, Kingston-upon-Thames and the West of England Main Line, which shares the route between London and Basingstoke. Together with these, it forms part of the network built by London and South Western Railway, which today is mostly operated by South West Trains. Network Rail refer to it as the South West Mainline.

Many sections of the line are relatively high-speed, with large stretches cleared for 100 mph running. The London end of the line has as many as eight tracks, but this narrows to four throughout most of the London suburbs and continues this way until Worting Junction near Basingstoke, from where most of the remainder of the line is two tracks. A couple of miles from the Waterloo terminus, the line runs alongside the Brighton Main Line, both lines pass through Clapham Junction - the busiest station in Europe (and one of the busiest in the world) by railway traffic.

Incentive

 * See London & South Western Railway

Several companies had proposed building a faster link from London to the South Coast around Southampton, which would have provided not only a route for transport but an important link in the event of war. At the time, Southampton was smaller than the nearby port of Portsmouth, but since Portsmouth's harbour was already used due to naval operations, Southampton was chosen as it had plenty of space for development.

An engineer had proposed the building a canal, but this was turned down due to being far too expensive. In 1831, a group of businessmen met together to discuss the possibility of a railway. As well as the line to Southampton, the company was also interested in building a line from halfway down their route towards Bristol via Newbury and Devizes. The company called itself the Southampton, London & Branch Railway and Docks Company.

The chosen route to Southampton was far from direct, as the route had been directed through the small market town of Basingstoke where the Bristol line would have left, and it missed major towns such as Guildford and Alton which would have been major revenue sources if the route had been more direct.

However, another company, the Great Western Railway, proposed a more direct route to Bristol, which stopped at several major towns, whereas the Southampton railway was mostly rural apart from the county town of Winchester. The GWR was approved, as was the Southampton railway (now unable to build the Bristol line) soon after. Despite the Bristol plan being made redundant, the company did not change its route. From then on, the Southampton railway and the Great Western Railway were often in competition with each other.

Construction
The first section to be opened was from Nine Elms, the LSWR's first London terminus in Battersea, to Woking (then named Woking Common) on 21 May 1838.

The remainder of the main line followed over the next two years:
 * Woking to Winchfield (Shapley Heath): 24 September 1838
 * Winchester to Southampton: 10 June 1839
 * Winchfield to Basingstoke: 10 June 1839
 * Basingstoke to Winchester: 11 May 1840. This last section was the most difficult on the route with an initial climb to Litchfield Tunnel and a ten-mile down-grade to Winchester.

To Portsmouth
The line proved successful, and it was not long before the company, renamed as London and South Western Railway due to their new plans, decided to expand. In 1848, the railway was extended from the Nine Elms terminus to the new station at Waterloo in the centre of London.

In 1865, another line was built from Guildford to Portsmouth which was more direct than the existing route.

The Mid Hants Railway
The original line proved far from direct. A secondary route had been planned via Guildford, Farnham and Alton from Woking to Winchester, which was more direct and served some other towns. This was built around the 1850s. The current route of the line from Brookwood to Farnham via Aldershot was built in 1870. The Guildford route was later closed.

The railway was often nicknamed 'The Watercress Line' due to the fact many communities on the line grew watercress. Although National Rail services only operate as far as Alton, a preserved line operates between Alton and Alresford known as the Mid Hants Watercress Line. The final section between Alresford and Winchester is closed, and is unlikely to re-open as housing and the M3 motorway have been built across the trackbed.

To Salisbury and Devon
A line was built from Bishopstoke (now Eastleigh) to Salisbury, then another was built from Basingstoke via Andover and became the first part of the West of England Main Line. The line ran via Yeovil to Exeter, then onwards via the north of Dartmoor to Plymouth (the GWR ran on the opposite side of Dartmoor).

The South Western Railway often contested with the Great Western Railway over trains to Devon, although the Great Western Railway's line from Reading to Taunton was later preferred by British Railways over the West of England Main Line.

The Southampton and Dorchester Railway
The Southampton and Dorchester Railway was also formed and built a line from 1845 to 1847 from Southampton to Dorchester. At the time it avoided Bournemouth, which was at the time barely a village, and ran via towns such as Ringwood before reaching Dorchester. The line was originally planned to continue towards Exeter, but this never came into effect. In 1865 the railway was extended south to Weymouth, the current terminus of the line. Later, as Bournemouth was developed as a seaside result, a line was built to run via Bournemouth, which became the main line. The Ringwood line was later closed by the Beeching Axe.

Rival and long distance Lines
The L&SWR's biggest rival was the Great Western Railway (GWR) who had originally cut the L&SWR's plans by building the line to Bristol. Both companies built several railways from their own networks into each other's territory.

In 1848, the GWR built a branch from Reading to Basingstoke. At first this was a fairly quiet railway which terminated at a separate terminus to the L&SWR's mainline station. However, when the rival company adopted standard gauge, a link was constructed between the two lines. This later became used for a freight route from Southampton to the Midlands via Oxford. Following the closure of the Somerset and Dorset Joint Railway, this route became used by long-distance services from Bournemouth to the Midlands.

Another line was built in 1873 (from Didcot and Newbury to Southampton). Originally, L&SWR ruled out allowing the line to use its own track but, after it fell into financial difficulties, it ended up joining the main line south of Winchester. The company also proposed building a line from Reading to Portsmouth via Basingstoke and Alton but the L&SWR found a cheaper solution for building the first stretch from Basingstoke to Alton by using a light railway. The Basingstoke and Alton Light Railway stopped the Portsmouth line from being built at the expense of being unprofitable and short-lived.

Major settlements on route
The main towns served by the route, starting from London, are:
 * London
 * Woking
 * Farnborough
 * Fleet
 * Basingstoke
 * Winchester
 * Eastleigh
 * Southampton
 * Totton
 * Christchurch
 * Bournemouth
 * Poole
 * Dorchester
 * Weymouth

Track
Between London Waterloo and Clapham Junction, the line has as many as eight tracks, with four pairs of tracks. It crosses beneath the Chatham Main Line where the Brighton Main Line runs alongside it on the southern side. At Clapham Junction, some of these tracks leave on the Waterloo to Reading Line and the remaining tracks are reduced to four. The Brighton Line, which also has four tracks, separates from it shortly afterwards.

The four tracks initially have a pair of "slow" tracks to the east with the two "fast" tracks on the western side. This arrangement continues to north of Wimbledon where a flyover transfers the northbound slow line across the fast lines, leaving the inner tracks being used for the fast services and the stopping services using the outer tracks. This arrangement continues to Worting Junction, just after Basingstoke. Many stations on this section had island platforms which have since been removed - this is evident with wide gaps between station platforms such as at Winchfield and Farnborough (Main). The island platforms survive at Esher and Walton-on-Thames, with the latter covered in weeds.

The line continues as double-track to Winchester but expands to three tracks through Shawford station with one up platform and fast and slow down platforms. There are four tracks from Shawford to Eastleigh. The line from Romsey via Chandler's Ford trails in just north of Eastleigh which is also the junction for the Fareham line. The line returns to double track until St Denys where the West Coastway Line trails in. At Northam the original route to Southampton Terminus carries on south towards Eastern Docks and the main route curves west to enter a tunnel and then Southampton Central Station. The line remains double-tracked most of the way to Weymouth, but there is a single-track section between Moreton and Dorchester South which constrains capacity.

Electrification
The suburban portion of the line, as far as the Pirbright Junction (for Alton), was electrified (750v DC third rail) by the London & South Western Railway and its successor, the Southern Railway, prior to World War II.

The main portion of the line to Southampton and Bournemouth was electrified in 1967. From then until 1988, trains on the Bournemouth to Weymouth section operated a push-pull system. One or two Class 438 4-TC units would be propelled from London to Bournemouth by a Class 432 4-REP unit, controlled from the leading cab of the Class 438 4-TC unit. At Bournemouth, one or both of the Class 438 4-TCs would continue over the unelectrified line to Weymouth hauled by a Class 33/1 diesel locomotive. Trains from Weymouth would follow the same procedure in reverse. Electrification was extended to Weymouth in 1988 and saw the introduction of the new Class 442 5-WES Wessex Electric trains. These were withdrawn by February 2007; Class 444 5-DES, Class 450 4-DES and Class 455 trains are now used.

Services
The majority of passenger services are currently operated by South West Trains.

Intercity and regional
Intercity services run as follows (Monday-Saturday off-peak):


 * Two trains per hour from Waterloo to Weymouth, with:
 * One calling at Woking, Winchester, Southampton Airport Parkway, Southampton Central, Brockenhurst, Bournemouth, all stations to Hamworthy, Wareham and Dorchester South.
 * One calling at Clapham Junction, Basingstoke, Winchester, Southampton Airport Parkway, Southampton Central, Brockenhurst, New Milton, Christchurch, all stations to Bournemouth, Poole and all stations to Weymouth.
 * One train per hour to Poole, calling at Clapham Junction, Farnborough Main, Fleet, Basingstoke, Winchester, Shawford, Eastleigh, Southampton Airport Parkway, Southampton Central, Totton, Ashurst New Forest, Brockenhurst and all stations to Poole.
 * One train per hour to Portsmouth Harbour, calling at Woking, Farnborough Main, Basingstoke, Micheldever, Winchester and Eastleigh, before branching off to serve the Eastleigh to Fareham line.
 * One train per hour between Bournemouth and Basingstoke operated by CrossCountry. Calling at Winchester, Southampton Airport Parkway, Southampton Central and Brockenhurst; these trains continue to Birmingham and further on to places such as Manchester and Nottingham
 * Two trains per hour between Basingstoke and Waterloo. Calling at Clapham Junction (alternate trains only) and Woking; these trains continue to serve the West of England Main Line.

Commuter
There are also many commuter services serving London. Those of note are:


 * Two trains per hour between Waterloo and Basingstoke, calling at Clapham Junction (alternate trains only), Surbiton, Walton-on-Thames, Weybridge, Woking and all stations to Basingstoke.
 * Two trains per hour between Waterloo and the Alton Line, calling at Clapham Junction (alternate trains only), Surbiton, West Byfleet, Woking and Brookwood before continuing down the Alton Line.
 * Two trains per hour between Waterloo and Woking, calling at Vauxhall, Clapham Junction, Earlsfield, Wimbledon, Surbiton and all stations to Woking.
 * Two trains per hour between Waterloo and Hampton Court, calling at Vauxhall, Clapham Junction and all stations to Surbiton before continuing down the Hampton Court Branch Line.
 * One train per hour between Romsey and Salisbury via Southampton, using the Eastleigh to Romsey Line and part of the Wessex Main Line. Travelling in a 'figure of six' route, trains from Salisbury go to Romsey, then call at Redbridge and all stations to Eastleigh, where the train leaves the SWML to return to Romsey.