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Class 166 Networker Express Turbo
The air-conditioned, 90 mph (145 km/h) three-car version of the Class 165 Networker Turbo, built for the Thames Valley expresses out of Paddington and working in the West of England since 2017.
Shown
Scale
230 ft (70.25 m) (the cars’ lengths added)
Class 166 Networker Express Turbo · schematic drawing GB Trains · gbtrains.uk/stock/166/ · CC BY 4.0
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Liveries
Former liveries 4
Thames TrainsFormer1996 to 2004Not drawn yet
First Great Western LinkFormer2004 to 2008Not drawn yet
First Great Western Dynamic LinesFormer2008 to 2015Not drawn yet
First Great Western (plain blue)Ran as First Great Western, then GWRFormer2015 to 2024Not drawn yet
- Type
- Diesel multiple unit
- Builder
- BREL (ABB Transportation from 1992)
- Family
- Networker, with Class 165 Networker Turbo, Class 465 Networker, Class 466 Networker
- Built
- 1992–1993
- In service
- since 1993
- Operators
- GWR
- Formation
- 3 cars
- Fleets
- Great Western Railway: 21
- Top speed
- 90 mph (145 km/h)
- Power
- Diesel · how it works
- Bogies
- BREL P3-17 power bogies (Networker Turbo); BREL T3-17 trailer bogies (Networker Turbo) · drawn with the same bogie component as Class 165 Networker Turbo
- Train length
- 230 ft (70.25 m) (the cars’ lengths added)
- Coupled
- 2 × 3 cars, about 461 ft (140 m) (the units’ lengths added)
- Car width
- 9 ft 3 in (2.81 m)
- Profile
- main-line
- Seats per train
- 246
- Total capacity
- 246 seats and 2 wheelchair spaces, with room for 116 standing (DfT's 2022 contract with GWR, Table 2; its Table 1 gives 244). The contract's figure, not a count
- Status
- In service with GWR: all 21, on local and regional services around Bristol (to Severn Beach, Westbury, Weymouth and between Cardiff and Portsmouth) and in Devon between Exmouth and Paignton. They moved west from the Thames Valley from October 2017, and were refurbished inside in 2021–2024. GWR passes into public ownership on 13 December 2026.
Car types
| Code | Car | Length | Doors per side |
|---|---|---|---|
| DMCL(A) | Driving motor composite with lavatory (DMCL(A)) | 77 ft 1 in23.50 m | 2 double |
| MS | Motor standard (MS) | 76 ft 3 in23.25 m | 2 double |
| DMCL(B) | Driving motor composite with lavatory (DMCL(B)) | 77 ft 1 in23.50 m | 2 double |
GWR's guide shows all seats as standard class: the A car's former first-class end behind the cab (16 seats) is kept, declassified, and the B car has none. The car codes are Angel Trains'.
Sources
How we source figures → · Spotted a mistake? Tell us → (opens in a new tab)
Show the 28 sources from Wikimedia Commons, First Great Western Link, via the Internet Archive, kitmasterbloke, via Wikimedia Commons and 12 more
- Class 166 Angel Trains21 three-car units, car lengths, width, 90 mph (145 km/h)
- GWR Rolling Stock Guide: Class 166 - 3 carriage turbo diesel trains (p. 20) and the Class 166 (Turbo) seating plan Great Western Railway, 2021 (PDF metadata: plan 16 November 2020, page 26 March 2021), p. 20operator: all 21 units with GWR; built 1992–93 (PRM upgrade 2016–19); the routes; all seating standard class (the seating plan)
- Gloucester railway station: GWR 166205 (photograph, CC BY-SA 2.0) Chris Morgan (geograph.org.uk 6313806), via Wikimedia Commons, 2 November 2019top-lights on alternate windows; car C's right side (the drawn side): two windows behind the cab, as drawn
- 165 profile.jpg: GWR Class 165/1 DMCL 58953 near Topsham (photograph, CC BY 4.0) kitmasterbloke (Flickr), via Wikimedia Commons, 24 December 2025the drawing's heights, door-leaf windows, cab door width, window rails, cab livery and colours (measured off the photograph); the saloon windows' frame, corners and transom and the door leaves' width, measured square on on the Class 165's same body (set T5, Kyle, 20 October 2026); the cab door's window height, re-measured (set TFF)
- British Rail Class 165 Wikipedia, accessed 2 October 2026height 12 ft 5 in (3.79 m; the Class 165's figure)
- British Rail Class 166s in Great Western Railway (First Group) livery (photographs of 166203, 166206, 166207) Wikimedia Commons (Southsea_Matt, CC BY-SA 4.0, and others), 2025-2026door colours: green on repainted units (2025-26)
- GWR Class 802 photographs (802001, 802018, 802101, 802108) Wikimedia Commons (Alex Noble CC0; Foulger Rail Photos CC BY-SA 2.0; Geof Sheppard CC BY-SA 4.0), 2017-2025GWR green and orange line of the drawing (as sampled for the Class 802)
- Class 165/166 Turbo: Braking Systems (Reading Turbo Maintenance Depot training manual, scanned) First Great Western Link, via the Internet Archive (fgw-reading-tmd-class-165-166-manuals), undated (2004-06); uploaded 2023, p. 5side elevation of the DMCL(A), 'DMOCL A' (measured)
- Class 165/166 Turbo: Construction & Couplers (Reading Turbo Maintenance Depot training manual, scanned) First Great Western Link, via the Internet Archive (fgw-reading-tmd-class-165-166-manuals), undated (2004-06); uploaded 2023, pp. 22, 9side elevation of the three-car DMCL(B) (measured); bodyshell sketch of the intermediate vehicle
- Class 165/166 Turbo: Air Supply & Distribution System (Reading Turbo Maintenance Depot training manual, scanned) First Great Western Link, via the Internet Archive (fgw-reading-tmd-class-165-166-manuals), undated (2004-06); uploaded 2023, pp. 18-19plan outlines of the driving and intermediate vehicles (the MS symmetrical, gangways at both ends)
- Transport (Commons debate, Hansard), quoting the Cotswold Line Promotion Group's winter 1993–94 newsletter UK Parliament, Hansard, 1994-04-21New Class 165 and 166 Turbo services through to Paddington were introduced in May 1993
- Turbo-trains (written answer, Hansard) UK Parliament, Hansard, 1991-06-06The order for the Paddington express Turbo vehicles (the 166s) was approved in March 1991, so the build came after this; the order, for 'BREL network turbo trains' (the builder)
- Modern Railways, March 1993 and August 1993 (pp. 478–479), as quoted on RailUK Forums 'Turbo history' Modern Railways (Ian Allan), via RailUK Forums, 1993-08-01The first 166 was still on test in early 1993, and the summer 1993 timetable extended the Turbos
- 'Chiltern 165018 (58818) bogie.JPG' (photograph: a bogie on 165018, with the shoebeam for the tripcock; CC BY-SA 4.0) Wikimedia Commons (Geof Sheppard)the bogie's likeness to the shared Sprinter style (layout only)
- 165 profile.jpg: GWR Class 165/1 DMCL 58953 near Topsham (photograph, CC BY 4.0) kitmasterbloke (Flickr), via Wikimedia Commons, 24 December 2025layout of the underframe equipment and the cab's lower side (the Class 165's; layout only)
- Class 165/166 Turbo: Braking Systems (Reading Turbo Maintenance Depot training manual, scanned) First Great Western Link, via the Internet Archive (fgw-reading-tmd-class-165-166-manuals), undated (2004-06); uploaded 2023, p. 5layout of the underframe equipment (the DMCL(A)'s side view)
- 166214 (58614) GWR branding detail.JPG (photograph, CC BY-SA 3.0) Geof Sheppard, via Wikimedia Commons, 2 May 2016the MS's underframe by its bogie (layout only)
- 166214 at St Philip's Marsh (7).jpg (photograph, CC BY 4.0) Harry Mitchell, via Wikimedia Commons, 2 May 2016the cab's lower side: the green skirt and steps
- First Greater Western Limited 2022: national rail contract (public register copy) Department for Transport, 8 December 2022 (contract dated 14 June 2022), p. 84seats per unit
- Gemini completes GWR Turbo fleet interior overhaul RAIL, 15 October 202421 three-car 166s in GWR's Turbo fleet, owned by Angel Trains; the interior overhaul at Wolverton, September 2021 to 10 September 2024
- More Turbos for Bristol area RAIL, 6 November 2017status: 166s on Bristol-area services from 25 October 2017, replacing 150s
- Transfer of Chiltern Railways services into public ownership (written statement) Department for Transport, GOV.UK, 13 October 2026status: GWR's services to pass into public ownership on 13 December 2026
- British Rail Engineering Ltd (people record ap96) Science Museum Group Collection, read 19 October 2026builder: BREL (1988) Ltd, sold in 1989 to a consortium including ABB, renamed ABB Transportation Ltd in 1992
- 166212 Exton.jpg (photograph) Wikimedia Commons, 7 August 2025car C's drawn (right) side, rectified: the window order and positions (within 25 mm), the cab door's rear edge, the door leaves about 5 ft 0 in (1,520 mm; photograph)
- 166210 Exeter St Davids 050825.jpg (photograph) Wikimedia Commons, 8 August 2025car A's drawn (left) side: the window order, as drawn (photograph; layout only)
- Class 165/166 Turbo: Construction & Couplers (Reading Turbo Maintenance Depot training manual, scanned) First Great Western Link, via the Internet Archive (fgw-reading-tmd-class-165-166-manuals), undated (2004-06); uploaded 2023, p. 15bogie types: P3-17 (power) and T3-17 (trailer)
- British Rail Class 166 Wikipedia, read 13 October 2026the livery's name, who ran it and its years (no colours taken)
- Didcot - FGW 166221 (2015); Stapleton Road 166 215 (2020); Dawlish - fGWR 166221 Paignton train (2023) (photographs) Wikimedia Commons, 2015-2023the livery's dates (photographs, 2015-2023; no colours taken)
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unverified
- The drawing: from two traced, undimensioned elevations in FGW's depot manuals, scaled to the 77 ft 1 in (23.50 m) car (they agree within 40 mm)
- Heights, door-leaf windows and the cab door's rear edge: from a photograph (the manuals draw window bottoms and door tops up to 140 mm lower and the cab door about 150 mm narrower)
- Wheelbase 8 ft 5 in (2,570 mm) and wheels 2 ft 8 in (820 mm): measured off the drawings (2,546-2,597 and 780-849)
- The MS: no manual draws its side; drawn with the DMCL's inner end at each end, which matches the window and door order on one side of 166217's MS (Reading depot, 2012 photograph); positions not measured
- Colours: sampled from photographs; no paint colour values have been published
- The bogies: BREL P3-17 power and T3-17 trailer bogies, laid out from the 165's 58953 (FGW's manual gives the 165 and 166 the same bogies; 166214 matches) (level and square-on); which end of the MS carries the power bogie isn't known
- The underframe: read off one level photograph of one side of a 165/1 driving car (58953), heights to about 40 mm; the other car types and the far side drawn alike (the manual and two more photographs agree where they show it); the case beyond the inner bogie from the 166's middle car
- The years of the former liveries come from Wikipedia's class article and the other sources listed, and haven't been checked against a second source.
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