British Rail Class 166
"Network Express Turbo" diesel
multiple units (also known as "Thames Turbos"
) were built by ABB at York Works from
These units are the express version of the Class 165
units and belong to the
family of trains.
These units are a modification of the Class 165
design. They have a top
speed of 90mph (suitable for mainline use), are carpeted throughout
and have air-conditioning. Externally, the class 166 can be
distinguished from a Class
by having a first class section at each end of the train,
and opening hoppers on every other window.
Other differences over a 165 are as follows:
- Two toilets (a 165 only has one toilet per unit)
- Tables in first class and in one third of the middle
- Dedicated cycle/luggage storage in the middle carriage
- Different interior panelling between the door and seating
- Grab rails painted in yellow instead of the blue found in the
Twenty-one 3-car units were built, numbered 166201-221. Each unit
was formed of two outer driving motors, and an intermediate motor.
The technical description of the formation is DMCL+MS+DMCL.
Individual carriages are numbered as follows:
were built to replace elderly Class 117, Class 119 and Class 121 "Heritage"
DMUs, and locomotive-hauled trains on services from London
Paddington along the
Great Western Main
- 58101-58121 - DMCL
- 58601-58621 - MS
- 58122-58142 - DMCL
Six cars were added to the original order in 1991 after Network SouthEast
acquired some of the
line services from
units to be
converted to Class 159's
the West of
166217 in First Great Western livery
at Old Oak Common in May 2007
When built, these units were operated by the Thames Line
and North Downs Line
subdivisions of Network SouthEast
and therefore carried
NSE blue, red and white livery with Turbo Express
between the two first class windows of the DMCL carriages.
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
services along the
North Downs Line
. Many services
operated by the 166 were branded as Turbo Express
it has been proposed to run the Class 166 along with the Class 165 units on the Cardiff Central to Portsmouth
Harbour route, subject to line clearance.
Following privatisation, the units passed to the Thames Trains
franchise, who introduced a new
blue, white and green livery. There were two variants of this
livery; the Class 166 units had the 'express' variant.
In April 2004, operation of the Thames Trains franchise passed to
the First Group
, who now operate the
company as First Great Western
The livery remained the same, but FGW Link branding was applied
over the obsolete Thames Trains logo.
||Cars per Set
||First Great Western
||166201 - 166221