Lymington Branch Line

The Lymington Branch Line is a branch line that goes alongside New Forest. The railway line is 9km long and is single track throughout the length. It diverges from South Western Main Line at Lymington Junction, and at Lymington Pier, trains connect to the Wightlink to the Isle of Wight. The Lymington branch line is electrified using the 750 V DC third-rail system – common in the former Southern Region of British Railways, even though the weekday service is operated by a diesel unit.

Previously, rolling stock is restricted to Class 411, 412, 421 and 423. Following the withdrawal of slamdoor stock from the rest of the SWT network in 2005 it was expected that by May 2005 at the latest the operation of the line would have been taken over by the new Class 450 "Desiro" units. However, SWT considered that due to the self-contained nature of the branch it would be more cost effective to continue Mk 1 operation. On this basis SWT bought and refurbished two British Rail Class 421 units to exclusively operate services on the line. Work carried out on the units included the fitting of central door locking and other safety features to allow them to remain in service beyond the November 2005 deadline for the withdrawal of slam-door stock and the reduction of the 4 carriage units to 3 carriages (3Cig) to address the extreme height difference between the train and the platform at Lymington Town. In summer 2009, South West Trains has plans to replace the trains with Class 158s on weekdays and Class 450s on weekends.