British Rail Class 377

Description

The units work suburban services in South London, and main line commuter services to Sussex, Surrey, Kent and the South Coast, on which they replaced 4Cig and 4Vep slam-door stock which came to end of their useful lives and which did not meet modern health and safety requirements. Built in the early 2000s, the units had a troubled introduction; being fully air-conditioned, their higher power consumption compared to the slam-door Mark 1-based stock that they replaced led to major upgrades being required to the 750 V DC third-rail power supply used in the former Southern region. The collapse of Railtrack following the Hatfield accident further delayed this upgrade work, and the new stock did not enter squadron service until 2003.

Class 377s are fitted with external CCTV. There is a disabled seating area, and both intermediate coaches have toilets. Bodyside power doors are electrically operated, a move away from the air powered systems of previous generation EMUs. Dual-voltage units are fitted with a Brecknell Willis high-speed pantograph, incorporating a pair of aerofoils on the pan knuckle to steady the pan head against the OLE contact wire. The configuration of a 5-car Class 377 unit is:

In 4-car units the driving cars are composite, with the first-class saloon between the driving cab and the first set of passenger doors. 4-car units also do not contain the MOS coach.

Couplers

The Class 377 uses Dellner couplers instead of the Tightlock type originally used on Southern's Class 375s. Southern's 375s were all converted to Class 377/3s - these reclassified units can still be identified by their 3-car formation. Note that Southeastern's 375s (sub-classes 375/3, 375/6, and 375/7) were also converted to Dellner couplers, but not reclassified; its 375/8 and 375/9 units were fitted with Dellner couplers as built.

Traction current supply

All units can receive power via third-rail pick-up which provides 750 V DC. There are eight pick-up shoes per unit (twice the number of previous generation 4-car Electric multiple units), and this enables them to ride smoothly over most third-rail gaps. The units in the 377/2, 377/5 and 377/7 sub-classes are dual-voltage, and are fitted with a pantograph to pick up 25 kV AC from overhead lines. On these units the shoe mechanism is air-operated so that when powered down, or working on AC overhead lines, they are raised out of the way. This is used on trains from Milton Keynes to East Croydon which use part of the West Coast Main Line between Milton Keynes and Willesden Junction, and then the West London Line towards Clapham Junction. These trains change to third-rail DC supply on a dual-voltage section of the West London line north of Shepherd's Bush. Since March 2009, dual-voltage Class 377 sets have also been operating some Thameslink Bedford to Brighton, Rochester and Ashford services. (See below).

Among the remaining units, the trailer coach in each unit has a recess in its roof where a pantograph could be fitted, to allow for future conversion to overhead AC power.

Additional units and the Thameslink Programme

In April 2007, as part of the Route Utilisation Strategy for the Brighton Main Line, it was announced that Southern would procure an additional 48 Class 377 carriages to replace an identical number of Class 319 carriages (12 4-car units) due to be transferred to First Capital Connect. Eleven further dual-voltage units were then added to the order, making a total of 23. They were ordered from Bombardier in March 2008 and were delivered in First's corporate colour scheme but with Southern spec interior (green seats). The units were commissioned at Southern's Selhurst depot in Croydon before being transferred to First Capital Connect's Bedford Cauldwell depot. The first of these, unit 377501, was delivered to Cauldwell depot on 27 February 2009 after making its first appearance through the Thameslink Central London core. The 377/5s operate mainly on Bedford to Brighton services but in the peaks form part of FCC's and Southeastern's new joint service to places such as Rochester and Ashford. Once FCC's new passenger vehicles come into service, the 377/5 fleet will be returned to Southern.

Delays in the construction of the Class 377/5s for First Capital Connect saw the temporary transfer of eight of Southern's Class 377/2s to FCC to enable them to implement the planned timetable changes on 22 March 2009; the loss of these units until September 2009 was covered by the temporary cascade of a number of Class 350/1s to Southern from London Midland, which operated services between East Croydon and Milton Keynes.

In September 2011 it was announced that Southern had begun the procurement of 130 vehicles, due to delays in the procurement of new Thameslink rolling stock that would prevent transfer of the 377/5s in time for the December 2013 timetable change. The contract was awarded to Bombardier in December 2011. The additional eight five-car units (from an option in the contract for 40 additional vehicles) are dual-voltage and known as Class 377/7.

In December 2011 three Class 377/2 units were transferred from Southern to First Capital Connect (now Thameslink) to allow more 12-car services to be run.

During mid-2013 the first of the new class 377/6s arrived from Derby for type testing, and since October 2013 these units have been used in passenger service, initially on a peak-hours London Bridge-West Croydon diagram.

Southeastern are expected to receive 25 Class 377 units in coming years according to Department for Transport documents published in September 2013, relating to the new combined Thameslink, Southern and Great Northern Franchise.

Southern

Thameslink

Southeastern

Since December 2016, Southeastern have had 8 units (377501-377508) on loan from Thameslink.

Southeastern

Southeastern are expected to receive 25 Class 377/1 Southern units in 2017 according to Department for Transport documents published in September 2013, relating to the new combined Thameslink, Southern and Great Northern Franchise.

Great Northern

Beginning 2016, 19 of the 23 Class 377/5 units were planned to be transferred for use on non-stop London-Cambridge services, however it has since been decided that the 29 Class 387/1s currently operating on Thameslink will be used instead.

Accidents and incidents

On 28 November 2016, unit 377442 suffered fire damage in its roof and the trim of a coach whilst in Eastbourne station.

London-Brighton Speed Record

On 11 September 2005, units 377472 and 377474 set the record for a London Bridge to Brighton run of 36 minutes 56 seconds.