The BR Class 166, officially named 'Networker Turbo Express', or 'Thames Turbo' is a UK commuter diesel multiple unit operated solely by Great Western Railway on their routes through the Thames Valley. As of July 2017, the units are now also being introduced into service in the Bristol area.

The BR Class 166 is featured in the Great Western Express add-on in the Great Western Railway livery. The unit has a maximum speed of 90 mph and 21 units were built between 1992 and 1993 for Network South East. These locomotives passed on to Great Western Railway after the privatization of British Rail.

Introduction Edit

Originally specified and built for British Rail, the BR Class 166 diesel-hydraulic mutiple unit belong to the Networker family and were originally known as Networker Turbos to distinguish them from the electrically propelled versions of the family. Still widely used throughout the Great Western Railway, they have long proved their reliability and endurance for over twenty years.

History Edit

The Networker family was to be a wide range of standardised EMU and DMU fleets that would revolutionise South East London, Kent, and the Great Western and Chiltern territories, comprising of both local commuter and more expressfocused stock. In 1989, after having already worked as a prototype Class 210, the Networker development train, now classified as the Class 457, began the testing of what would become the technical arrangements of the average third rail Networker. The following year saw a conversion to overhead equipment for testing, and another reclassification to the Class 316. When built, these units were operated by the Thames Line and North Downs Line subdivisions of Network SouthEast.

Despite the extensive electrical testing, some of the first Networkers to be built at ABB York were diesel-hydraulic multiple units for the Great Western and Chiltern Main Lines, the Class 165 and Class 166, known as the Networker Turbo and Networker Turbo Express respectively. Both of these lines were not electrified, such a development was not deemed possible at the time, and so diesel traction was still a necessity.

The Class 166 Networker Turbo Express was designed and built as a faster variant of the earlier Class 165. The 90 mph-capable Class 166 would be able to cover longer distance stopping services while the slower Class 165 worked the local services out of London Paddington. As the Class 166 was designed with express workings in mind, they were also fitted with air-conditioning, an extra toilet, first class with tables, luggage storage and a fully carpeted interior with different panelling.

A total of 21 Class 166 DMUs were delivered to Network Southeast between 1992 and 1993, for use as express commuter stock out of London Paddington and out along the Thames Valley. The fleet has subsequently operated as such for Thames Trains, First Great Western Link, First Great Western and now, Great Western Railway. The fleet’s Thames Valley-exclusivity was however stopped by GWR, as a handful of 166s have begun working the Severn Beach Line, having been replaced by Class 387 Electrostars, which themselves are a derivative of the Networker family.

Their main destinations included fast-trains to Reading, Newbury and Oxford, with some services continuing beyond Oxford to Banbury and Stratford-upon-Avon, or along the Cotswold Line to Evesham, Worcester, Great Malvern and Hereford. Units are also used on the Reading to Gatwick Airport services along the North Downs Line. Many services operated by the 166 were branded as Turbo Express in the timetables.

Following privatisation, the units passed to the Thames Trains franchise. In April 2004, operation of the Thames Trains franchise passed to the First Great Western Link, and subsequently to First Great Western.

In 2012, First Great Western took delivery of five Class 180 Adelante units for Cotswold Line services, and three-car Class 150Sprinter units for Reading to Basingstoke Line services, allowing Class 165 and 166 units to be used entirely for Thames Valley services.

In the past 7 years, the Class 166 fleet has undergone multiple refreshes to bring them up to standard. An £8 million project was announced in 2010 and saw the fleet receive repainted interiors, upgraded toilets, a new GPS-based Passenger Information System and retrimmed carpets & seats. Four years later, and the Class 166s also received new headlights, toilets and door buttons & alarms. The most recent change for the fleet is the gradual re-livery into Great Western Green, and they will soon receive 2+2 seating as more of the fleet moves out of London.

From July 2017, a number of Turbos were transferred to Bristol for services on the Severn Beach Line to provide extra capacity during busy services. From October 2017, the 166s began on Weston-super-Mare to Bristol Parkway and Cardiff Central to Taunton services. As more of the 166s moved to Bristol, they also started service on the Heart of Wessex Line and Golden Valley line in 2018, replacing Class 150 units on these lines. Although their operation on the Thames Valley section of the GWML is gradually being phased out, Class 166s also remain in full operation on unelectrified branches of the line, such as the Marlow Branch.

Great Western RailwayEdit

21 BR Class 166s are currently operated by Great Western Railway. They became part of Great Western Railway when First Great Western Link won the Thames Valley Franchise in 2004. This became part of First Great Western and eventually Great Western Railway. They are currently operate on services from London Paddington to the Thames Valley. Upon the completion of the Great Western Main Line electrification, they will be moved to the Bristol area, being replaced by BR Class 387 units.

Timetable Edit

The BR Class 166 runs a 24 hr timetable on Great Western Express. Links can be found below to the appropriate timetables:

Driving the Locomotive Edit

For information on driving the locomotive, see this page.

Great Western Express
Locomotives BR Class 43 HST - BR Class 66 - BR Class 166
Rolling Stock BR Mk3 - HKA Hopper - FKA Container Flat
Stations London Paddington - Acton Main Line - Ealing Broadway - West Ealing - Hanwell - Southall - Hayes & Harlington - West Drayton - Iver - Langley - Slough - Burnham - Taplow - Maidenhead - Twyford - Reading
Other Locations Old Oak Common TMD - Airport Junction
Operators Great Western Railway - DB Cargo UK
Tutorials Class 43 Introduction - Class 166 Introduction - Class 66 Introduction - Station Stopping
Scenarios Down the Line - West World - Christmas Closures - Aggregate Industries - Drag Line
Journeys Commuter Driver - Express Driver - Freight Driver - Mainline Driver
Guides Driving the BR Class 66 - Driving the BR Class 43 - Driving the BR Class 166 - AWS, TPWS & DSD - GWE Collectibles
Miscellaneous Signalling - Service Timetable
British Locomotives and Multiple Units
Diesel Locomotives BR Class 08 - BR Class 09 - BR Class 20 - BR Class 31 - BR Class 33 - BR Class 37 - BR Class 40 - BR Class 43 - BR Class 45 - BR Class 47 - BR Class 52 - BR Class 66
Diesel Multiple Units BR Class 101 - BR Class 166
Electric Multiple Units BR Class 377
London Underground Stock 1972 Mark 2 Stock
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