| operator =

| operatorclass =

| powerclass =

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| fleetnumbers =

| officialname =

| nicknames = Shed,

| lastrundate =

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| preservedunits =

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| disposition = In service

| notes = References to "UIC II" and "EU Stage IIA" relate to emissions control regulations set by the UIC and EU, respectively. In general, and without regard for subsequent modifications, locomotives ordered before will be original specification, Initially, the locomotives were expected to be allocated the TOPS Class 61, the Class 66 designation was confirmed in July 1996.

The EMD 710 12-cylinder diesel engine is a development of a two-stroke engine used for over 20 years, whilst the EM2000 control equipment is the same as that used on the Iarnród Éireann 201 Class. EWS reduced the locomotive's time into operation through specifying cab systems laid out like the Class 59, whilst increasing availability with a fuel tank of capacity, compared to on a standard Class 47. whilst also acquiring the nicknames of "sheds" for the EWS (now DBS) locomotives (due to their upturned roof looking like a shed roof) with the Freightliner locomotives being called "Freds" as a portmanteau of Freightliner and Shed.

Continental Europe

The Class 66 design has also been introduced to Continental Europe where it is currently certified for operations in Germany, the Netherlands, Belgium, Luxembourg, Sweden, Norway, Denmark, France, and Poland, with certification pending in the Czech Republic and Italy. They currently operate on routes in Sweden and Denmark and between Germany, Belgium, The Netherlands and Poland. As a result of its well-known British identity, EMD Europe markets the locomotive as "Series 66".

UK importation

By 2011, following an increase in UK rail traffic after the 2008 Global Economic Crisis, EMD were struggling to source critical components of the locomotive — specifically castings. The final units of the Class 66 were produced in the London, Ontario plant that year following an industrial dispute and the introduction of new EU crash and emissions regulations which culminated in the cessation of production.

Due to a reduction in European freight volumes and migration of several operators to electric traction using multi-current locomotives such as the Alstom Traxx and Siemens Eurosprinter, since mid-2012, a number of EMD Series 66 locomotives have been imported by GBRf and converted to UK type specifications. To date:

  • 2012: Three ex-Dutch locos, which have been numbered 66747–749. The former identities of these were DE6316, DE6313 and DE6315 respectively.
  • 2013: Two ex-German "Rush Rail" locomotives, which have been numbered 66750 and 66751. The former identities of these were DE6606 (also used in Sweden with the number T664025) and DE6609 (also 2906) respectively
  • 2019: Three ex-Swedish locomotives, which have been numbered 66790–792. The former identities of these were T66403, T66404 and T66405 respectively.
  • 2024: Eleven locomotives from France, which have been numbered 66306–316.

Emission compliance

Numbers 66752-779 were the last Class 66s ordered for service in Great Britain because of increasingly stringent emission regulations. 66779 was the last Class 66 ever to be built. Although the Class 66s meet stage 3a of the regulations, they do not meet stage 3b. Stage 3b would have required additional exhaust treatment equipment that could not easily be accommodated within the UK loading gauge. The same restrictions apply to the and . The restriction does not apply to second-hand locomotives, provided that they are imported from within the European Union. The purpose of the regulation was to put a cap on the total number of non-compliant locomotives in the EU.

Current operators

Class 66 operators in Great Britain are:

  • Colas Rail
  • DB Cargo UK
  • Direct Rail Services (DRS)
  • Freightliner
  • GB Railfreight
  • Heavy Haul Rail

DB Cargo UK

thumb|Class 66 locomotive 66034 in DB livery at Didcot Parkway

DB Cargo UK bought out EWS. Their Class 66 fleet includes four locomotives capable of banking heavy trains over the Lickey Incline. On these specific locomotives, the knuckle coupler has been modified to allow remote releasing from inside the cab, whilst in motion. It also includes fifteen locomotives fitted with RETB signalling equipment, for working in northern Scotland and RETB-fitted branchlines. A few DB Cargo UK Class 66s are now working in Europe as part of DB Cargo France and DB Cargo Polska.

GB Railfreight

thumb|[[GB Railfreight 66744 waiting at Victoria station.]]

GB Railfreight initially leased seventeen Class 66/7 locomotives, before increasing its fleet to 32. During April 2006 five more low-emission locomotives (numbered 66718-722) were delivered, liveried for use on the Metronet/Transport for London contracts. A further order for five more locomotives (66723-727) was delivered in early 2007, and another five locomotives (66728–732) in April 2008. 66733-746 are formed of Class 66s from Direct Rail Services, Freightliner and Colas Rail. In 2011 66720 was painted in a special "Rainbow" livery. In June 2012, 66734 derailed at Loch Treig whilst working 6S45 North Blyth–Fort William and was consequently cut up on site and scrapped.

In September 2013, GB Railfreight announced a new order of a further 8 Class 66/7 locomotives from EMD, the first of the class to be built at EMD's Muncie, Indiana plant. On 2 February GBRf ordered a further 13 locomotives. These 21 locomotives are numbered 66752–772. Numbers 66752–756 were shipped from America and arrived at Newport Docks in July 2014. No. 66752 has been named The Hoosier State, a nickname for Indiana. A further seven locomotives (66773–779) were later added to the fleet, utilising six power units that had been in the UK, plus one recovered from the scrapped 66734. The presence of these power units in the UK circumvented European emission compliance regulations and permitted them to be exported to EMD Muncie for installation in further class 66 bodyshells.

The final Class 66 built, 66779, remained under a tarpaulin until 10 May 2016 when it was revealed at the NRM York with a special livery and nameplates to commemorate the fact it is the final Class 66 ever built for the British market. The locomotive has been painted in BR Lined Green and named Evening Star, in reference to BR Standard Class 9F 92220 Evening Star which was the last BR steam locomotive to be built. It was unveiled in a special ceremony inside the Great Hall at the National Railway Museum in York on 10 May 2016 before staying there opposite its namesake, No. 92220, for two weeks. At the same ceremony, the CEO of GBRf, John Smith, handed the curator of the National Railway Museum a document offering 66779 to the national collection when it is retired in about 40 years time.

In addition to those locomotives sourced from domestic operators (Direct Rail Services, Freightliner, Colas Rail and DB Cargo UK), eight further locomotives have been obtained from European operators. A further five have been purchased from Heavy Haul Power International and will be transferred from Germany beginning in April 2021. The locos will go to Doncaster to be converted to UK specification.

Former operators

thumb|66305 in [[Fastline livery in the snow]]

Former Class 66 operators include:

  • Advenza Freight
  • Fastline

Fastline operated intermodal services between Doncaster and Birmingham International Railfreight Terminal (BIFT), and Thamesport, in North Kent, using refurbished locomotives. The company ordered five Class 66/3 locomotives to operate a coal flow from Hatfield Colliery, which were delivered in 2008.

Following the demise of Jarvis in 2010, and Fastline going into administration on 29 March 2010, these locomotives were placed in storage, being towed to Direct Rail Services' Carlisle Kingmoor and Crewe Gresty Lane depots for storage. During 2011, DRS repainted the five ex-Fastline locomotives and added them to their own fleet, keeping their original numbers.

Future operators

In January 2026, DB Cargo UK announced that it was to sell 25 locomotives to Bulgarian operator Grup Feroviar Român. The locomotives include 66006, 66009, 66014, 66024, 66027, 66040, 66047, 66069, 66075, 66076, 66080, 66085, 66086, 66087, 66089, 66095, 66110, 66111, 66115 and 66197.

Driver reception

The British train drivers' union ASLEF has complained that the locomotives are unfit and unsafe to work in, citing excessive heat, noise levels and poor seating.

In April 2007, ASLEF proposed a ban on their members driving the locomotives during the British summer 2007 period. Keith Norman, ASLEF's general secretary, described the cabs as "unhealthy, unsafe and unsatisfactory". Research showed that in July 2006, when the weather had been extremely hot, the number of incidents where a driver had passed a signal at danger (SPAD) increased. EWS entered into discussions and made amendments to a series of trial locomotives, In June 2007, progress on the issue led ASLEF to withdraw its threat of industrial action.

In Norway, CargoNet related complaints about the noise levels in the CD66 variant of the Class 66 resulted in higher pay rates for drivers.

Accidents and incidents

  • On 28 February 2001, 66521 was involved in the 2001 Great Heck rail crash/Selby rail crash which resulted in 10 deaths including the driver Stephen Dunn. The locomotive was written off and scrapped as a result of major damage sustained in the accident.
  • On 9 February 2006, a freight train hauled by English Welsh & Scottish 66017, derailed at Brentingby Junction near Melton Mowbray. Having passed a signal at danger, the locomotive and the first three wagons were derailed at catch points at the end of the Up Goods Loop. There were no injuries.

thumb|right|66 048 lies in the snow and trees following the Carrbridge derailment.

  • On 4 January 2010, a freight train, hauled by 66048, derailed at in snowy weather, blocking the Highland Main Line. Having passed a signal at danger the train was derailed at trap points, subsequently falling down an embankment into trees and injuring the two crew members. The locomotive was hauling container flats from Inverness to Mossend Yard on behalf of Stobart Rail. The line was reopened on 12 January.
  • On 21 November 2011, 66111 derailed between Exeter Central and Exeter St Davids on working an engineering works service.
  • On 28 June 2012, GBRf operated 66734 derailed at Loch Treig whilst working the 6S45 North Blyth to Fort William Alcan Tanks. Due to its position and the environmental risks associated with recovery, after agreement from owners Porterbrook it was cut-up on site and the mechanics recycled as spare parts.
  • On 1 August 2015, 66428 was hauling an engineering train that ran into the rear of another engineering train at Logan, Ayrshire. It was severely damaged. The train that was run into was hauled by 66305.
  • On 14 August 2017, 66713 was hauling a freight train that derailed near , due to defective suspension on the wagon that was first to derail. The railway between Ely and was closed for a week.
  • On 4 September 2018, 66230 was hauling a freight train which collided with a vehicle on a level crossing at Dollands Moor Freight Yard, Kent. One cab was extensively damaged in the post-impact fire. The locomotive was stored in Toton TMD.
  • On 23 January 2020, 66154 was hauling a freight train which derailed at Wanstead Park and ran for before stopping near station.
  • On 23 March 2020, 66057 ran through a buffer stop at the end of a siding at and was derailed. The derailment caused the locomotive to foul the main line, and a diesel multiple unit, unit number 170 107, collided with the derailed locomotive at around . No one was injured. The driver of the locomotive was subsequently convicted of an offence contrary to the Health and Safety at Work etc. Act 1974. He was sentenced to 8 months' imprisonment, suspended for 18 months.
  • On 11 November 2020, 66603 was hauling a freight train that derailed at . The derailment was caused by broken rail fastenings which allowed the track to spread.
  • On 19 August 2021, 66754 was hauling a freight train which collided with a tractor on a level crossing between and in Cambridgeshire. The locomotive and three wagons were derailed.
  • On 24 December 2021, 66779, working a train from Hams Hall (near Birmingham) to London Gateway derailed on the down Thames Haven line while on the approach to the port near to Stanford-le-Hope in Essex.
  • On 5 July 2022, 66729 was hauling a freight train that passed a signal at danger and ran into the rear of another freight train near Loversall Carr Jn, Doncaster.
  • On 19 October 2022 66739 was hauling a loaded cement train from Clitheroe Castle Cement Gb to Carlisle N.Y. when eight wagons derailed at Petteril Bridge Junction with one crashing into the River Petteril and one half way down the embankment.
  • On 5 April 2024, 66776 passed a red signal and was derailed at .

Sub-classes

Minor differences between different orders, and different operating companies have resulted in a number of subclasses being defined.

{|class="wikitable" style="clear:both;"

|-

!Subclass

!Quantity

!width=80px|Loco nos.

!Operators

!Comments

|-

| rowspan="2" |Class 66/0

  • 15 locomotives have been sent to the Polish division of the DB Cargo group, DB Cargo Polska: 66146, 66153, 66157, 66159, 66163, 66166, 66173, 66178, 66180, 66189, 66196, 66220, 66227, 66237, 66248.
  • 66048 was withdrawn in 2016 following an accident at Carrbridge
  • 66230 is in storage at Toton TMD following an accident at Dollands Moor.

|-

|5

|

|Direct Rail Services

|On long-term lease from DB Cargo UK, all in DRS livery.

|-

|Class 66/3

|16

|

|GB Railfreight

|