British Rail Mark 3

British Rail Mark 3
British Rail Mk 3 at Marylebone in original 'InterCity' blue and grey livery

Mark 3 at Leicester.

A Mark 3 TS coach pictured at London Paddington, in old First Great Western colours

A Mark 3 TS coach pictured at Aberdeen, in GNER colours

The original BREL-designed interior - this photo is of a First Great Western standard class Mark 3 coach

Interior of a new First Great Western high Density HST Carriage

British Rail's third fundamental design of carriage was designated 'Mark 3' (also described as Mark III), and was developed primarily for the InterCity 125 High Speed Train (HST). The vehicle was also developed as a conventional loco hauled coach for the West Coast Main Line (WCML) northern electrification scheme - this was the first Mark 3 derivative to enter revenue service in 1975, with the definitive HST version appearing a year later. The final batch was built in 1988, although multiple unit designs based on the Mark 3 bodyshell continued to be built into the early 1990s. The Mark 3 and its many derivatives are widely recognised as one of British Railways Board's greatest engineering achievements, with the vast majority of the surviving fleet still in revenue service on the British railway network to the present day.

Construction

The Mark 3 looks similar to Mark 2D, 2E and 2F coaches, but is a completely different design. A difference aiding quick recognition is the ridged roof of the Mark 3s compared with a smooth roof on the Mark 2s.

The bodyshell is 75 feet (22.86 m) long, almost 10 feet longer than the Mark 2, of full monocoque construction, and has gained a reputation within the railway industry for its exceptional strength and crashworthiness. Another important advance over its predecessor was the adoption of secondary air suspension between the body and the bogies giving the passengers an exceptionally smooth ride. The bogies, classified BT10, were designed specifically for the Mark 3 and have coil spring primary suspension with hydraulic dampers enabling a maximum speed of 125 mph (200 km/h) — the Mark 2 is limited to 100 mph (160 km/h). Disc brakes in place of the Mark 2's clasp brakes completed the engineering package - enabling efficient deceleration from 125mph and almost silent brake operation.

Ancillaries such as electrical and air conditioning systems were grouped together in discrete modules housed behind an aerodynamic skirting between the bogies; on the Mark 2 these were mounted above and below the passenger seating area. The lighting and air conditioning fittings were for the first time integrated into the ceiling panels. Other new features (first seen on the Mark 2F) were the pneumatically operated automatic gangway doors which were triggered by pressure pads under the floor, and a speed operated central door locking system for the manually operated slam-doors.

The main difference between the HST vehicles and the loco-hauled Mark 3A relate to electrical supply arrangements. HST MK3s take an industrial voltage/frequency 3-phase supply directly from an auxiliary alternator in the power car to supply on board equipment such as air conditioning. The loco hauled vehicles take a standard single phase 1000 V AC or DC train heat supply from the locomotive and convert it through motor alternator units located under the floor. These convert the train supply to 3-phase 415/240 V 50Hz AC to power air conditioning and other ancillaries. This difference makes the two types non-interconnectable in service conditions. The other main difference is the lack of buffers on HST coaches.

The later Mark 3B build provided additional 1st Class loco hauled vehicles for the West Coast Main Line. These are virtually the same as earlier Mark 3As, but have an improved motor alternator unit with compound wound motor and seating derived from the Advanced Passenger Train (APT)

Mark	Built	Features
Mark 3	1972-85	The basic model, for use in High Speed Train sets
Mark 3A	1975-84	The basic model, for use in locomotive-hauled rakes
Mark 3B	1985-88	FO/Open First vehicles with interior based on First Class interior of the failed APT train - InterCity 80 seats and improved interior saloon lighting diffusers

Usage

The Mark 3 design proved to be highly adaptable for use in BR's multiple unit stock of the 1980s, with the following classes having Mark 3 based bodyshells:

• AC EMU Classes
  • Class 317
  • Class 318
  • Class 319/Class 320/Class 321/Class 322
• DC EMU Classes
  • Class 442
  • Class 455
• DMU Classes
  • Class 150
  • Class 156
  • Class 210

The Mark 3 bodyshell was also used as the basis for Northern Ireland Railways' 450 Class DMU.

Since 1977, the Royal Train has used nine specially equipped Mark 3 coaches to transport members of the Royal Family. These were rebuilt from the original HST prototype vehicles.

Grand Central, a new open access operator on the ECML, will use HST sets on its newly inaugurated services between London and Sunderland [1]. The Mark 3 coaches to be used are of the loco-hauled type, and so are undergoing modifications to their couplers and electrical systems to make them compatible with Class 43 power cars. They have a limited role on the WCML, with the overnight Caledonian Sleeper services between Scotland and London Euston using Mark 3 sleeping cars.

Following the introduction of Virgin Trains' Pendolino electric multiple units onto the WCML, a huge surplus of Mark 3 vehicles was created, ending up in storage at Long Marston. Some of the former Virgin coaches were refurbished and cascaded onto the Great Eastern Main Line, replacing the Mark 2E/2F vehicles which were working London-Norwich services. They also continue to be used by First Great Western on the Great Western Main Line, and National Express East Coast (NXEC) on the East Coast Main Line franchise. Virgin have retained at least one complete Mark 3 set with a Class 90 locomotive - initially used to cover peak time Euston-Birmingham services whilst the Pendolinos underwent modifications, but it is now covering the loss of 390033 which was written off after the Grayrigg derailment in 2007.

In January 2007, the first of the refurbished Mark 3 sets for the ECML were unveiled by previous franchisee GNER - these have been internally refitted to the same standard as the "Mallard" Mark 4 stock with the same styles of seating and lighting. The new Mark 3 Mallard sets have been converted by Wabtec in Doncaster, and will be steadily rolled out over the next two years - the final refurbished set expected to enter service in early 2009.

Cargo-D, a newly established rolling stock logistics company has acquired 18 ex-Virgin West Coast Mark 3 coaches and repainted them in their original British Rail blue/grey livery and Inter-City branding - the first time the livery has been seen on the coach since the late 1980s. The stock is used primarily for the company's own "Rail-Blue" charter operation and for leasing to Wrexham & Shropshire (see below).

NXEC plans to introduce new stopping services on the ECML using formations of Mark 3 coaches pulled by Class 90 locomotives for stopping services to York. Wrexham & Shropshire, a new open access operator, also has plans to use its own rake of Mark 3 coaches pulled by a Class 67 locomotive for its services between London and Wrexham. CrossCountry have reinstated HSTs on the CrossCountry franchise in response to criticism of the lack of seating capacity on the Voyager DEMUs used by previous incumbent Virgin Trains. In order to satisfy demand for these new HST sets, it is anticipated that more loco-hauled Mark 3 coaches will need to be converted for HST operation.

Mark 3 sleeping car at the Colne Valley Railway

These developments will ensure that the vast majority of the Mark 3 fleet will be back in revenue service, amid earlier fears that a large number of the coaches may end up being exported or scrapped. Arising out of British Rail's over-provision of stock for sleeper services that have long since been withdrawn, two-thirds of the Mark 3 sleeping car fleet were either stored or scrapped.

Variants

HST vehicles

Original formation

The original Mk3 coaches delivered as part of HST sets for Western Region (Class 253) contained Trailer First (TF), Trailer Second (TS), and Trailer Buffet Second (TRSB) variants in formation TF-TF-TRSB-TS-TS-TS-TS. Complaints from train guards about engine noise in the guards' compartments (which were located in the HST Power cars) led to an additional variant, the Trailer Guard Second (TGS), which was based on the TS but with the end vestibule and one seating bay replaced by a guard's compartment. This replaced the last TS in all sets from 1980 onwards. Sets delivered for Eastern Region (Class 254) contained 8 coaches with an additional Trailer Kitchen Unclassified (TRUK) in the middle of the Trailer Seconds (sets 1-20) or with a Trailer Buffet Unclassified (TRUB) in place of the Trailer Buffet Second, and an additional TS (Sets 21-32).

Previous formations

Virgin Trains frequently operated HST sets in shortened formations during the late 1990s, the most common being five-car sets. This was to give the trains better acceleration, so as to be similar to the Voyager units.

Current formations

Most operators of HST sets form them in eight-car sets, with National Express East Coast operating nine-car sets, with an additional standard-class vehicle.

Hauled stock

Mark 3A coaches were deployed on WCML expresses out of Euston to bring the three main long-distance routes from London up to the same standard. Initial variants were Second Open (TSO) and Open First(FO). Catering continued to be Mark 1 stock until the introduction of Restaurant Buffet (RUB) vehicles in 1979-80. In 1988 the process was completed with the elimination of Mk 1 parcels vehicles and their replacement with Mk 3 derived Driving Van Trailers, making the WCML push-pull.

Scottish Region push-pull services were initially made up of four TSO and one FO Mark 3A coaches with a Mark 2F DBSO. This was later changed when the FO was converted to a CO by the declassification of half a coach and installation of a partition between the two classes. An SO was removed from the formation. These vehicles were removed from the Scottish regional routes in 1989 when they were replaced with Class 158 multiple unit stock.

Multiple Units based on the Mark 3

These entered service between the early 1980s and early 1990s. Electric multiple units include the 25 kV AC EMUs of the Class 317 and Class 318, and the 750 V DC EMUs of the Class 455 and Class 442. Also with a dual voltage EMU which is the Class319. Diesel multiple units include the short-lived diesel electric Class 210, and the diesel mechanical "Sprinters" of the Class 150. The cars for Classes 150, 210, 317, 318 and 455 units are built on 20 m frames, and are outwardly similar. However, those for Class 442 are on 23 m frames. The Class 155 and derived Class 153, while being of the "Sprinter family", are in fact based on Leyland bus components, not the Mk 3 carriage. The final batch of "Sprinters" of Class 158 (some rebuilt as Class 159), are of a design intermediate between that of the Mk 3 and the later Mk 4. In addition, a fleet of nine 450 Class DMUs were built for Northern Ireland Railways using Mark 3 bodyshells and Mark 1 underframes, together with refurbished power units and traction motors.

Mark 3 coaches overseas

The Mark 3 in Ireland

A Mark 3 standard coach pictured at Heuston Station, Dublin, in Intercity livery

Republic of Ireland's national rail operator, Iarnród Éireann, operates a fleet of Mark 3 carriages built between 1984 and 1989 with bogies to suit the Irish gauge of 1600 mm (5 ft 3 in). The fleet is 124 Mark 3s and 9 Mark 3 international. As of 2007 they continue to form a large part of the intercity rolling stock on the Irish railway network. All the Irish coaches were built with automatic plug doors - the doors caused some concern at the time as additional time and resources were required to perfect them. Most of the fleet is air-conditioned except for a small number of coaches built originally as outer suburban stock which run in push-pull configuration. A number of coaches are first class, and there are several dining carriages and some driving van trailers (DVTs include passenger seating). An accompanying generator van supplies power.

In 2006/7, new carriages built by CAF of Spain (widely referred to as "Mark 4s"), were introduced on the important Dublin-Cork route. The displaced Mark 3s have been cascaded to other Inter City routes. Iarnród Éireann plans to replace most of the Mark 3s within the next few years with "regional railcars" (DMUs).

References

• Cooper, B K (1981). British Rail Handbook. Shepperton: Ian Allan. ISBN 0 7110 1027 7.
• Fox, Peter (1984). Coaching Stock Pocket Book sixth edition. Sheffield: Platform 5. ISBN 0 906579 35 X.
• Haresnape, Brian (1979). British Rail 1948-78: A Journey Through Design.
• Mallaband, P (1976). The Coaching Stock of British Railways 1976. Oxford: RCTS. ISBN 0 901115 39 4. {{cite book}}: Check |isbn= value: checksum (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
• Mallaband, P (1980). British Rail Coaching Stock 1980. Oxford: RCTS. ISBN 0 901115 50 9. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)

See also

• InterCity 125
• Class 43 power cars