Mark 3
Built 1972 - 1988. 23 metre length. Fully integral steel monocoque construction. BREL BT10 bogies. 125mph maximum speed.
Slam doors and track discharge toilets (Some vehicles now being refurbished with sliding plug doors and retention toilets). Seated 72 in standard class when new, now seat between 64 and 84 in differing layouts.
Built by BREL for use in both fixed formation HST trainsets and as conventional loco-hauled coaching stock.
First prototype vehicles built in 1972, first production vehicles entered squadron service in Western Region HST sets in 1976.
HST vehicles are designated mark 3, and utilise a non-standard 415V three phase train supply.
Locomotive-hauled coaches were classified Mark 3A, and were initially deployed on the West Coast main line, as well as with Scotrail from 1979 on Edinburgh - Glasgow push-pull services.
A new batch of Open First and Open Brake First vehicles, classified Mark 3B were built in 1985 with Advanced Passenger Train-style 'IC80' seating and revised lighting for 'Manchester Pullman' services, replacing the mark 2 vehicles which had been in service since 1966. The three brake vehicles, 17173 - 175, built for these services were the only mark 3 passenger brake vehicles constructed, and are now in use with GWR on their 'Night Riviera' sleeper services. The last mark 3 vehicles contructed were 52 Mark 3B Driving Van Trailers for West Coast main line services in 1988, to allow these services to operate in push-pull mode.
The design was adapted for Irish Rail and for the Class 442 'Wessex Electrics', which both featured powered swing plug doors.
Mark 4
Built 1989 - 1992. 23 metre length. Fully integral steel monocoque construction - heavier than mark 3s. SIG BT41 bogies. 140mph maximum speed, but restricted to 125mph due to the signalling system on the ECML being unsuitable for 140mph running.
Powered swing plug doors and retention toilets. Seat 76 in standard class (68 in 123xx vehicles with disabled facilities).
Built by Metro-Cammell between 1989 and 1992 for use on the East Coast main line after electrification in combination with class 91 locomotives.
Standard 1000V train supply allows them to be powered by any appropriate train supply fitted diesel or electric locomotive.
Time Division Multiplex multiple working equipment allows push-pull operation between Mark 4 DVTs and class 89, 90 or 91 electric locomotives.
Bodyshells built to accommodate a tilting profile of 6 degrees (IIRC) to permit a future order of Mark 4-T tilting vehicles for use on the West Coast main line, for which SIG would have developed a new design of tilting bogie that probably would have been akin to that now found beneath the Class 390 Pendolinos. Order not taken up.
Mark 5
Built 2017 onwards. 22 metre length (22.37m driving/end vehicles, 22.2m intermediate vehicles). Fully integral aluminium monocoque construction. CAF low trackforce bogies. 125mph maximum speed, but restricted to 100mph due to the capabilites of the locomotives they will work with.
Powered sliding plug doors and retention toilets. Seat up to 69 in standard class (Transpennine Trailer Standard vehicles).
75 Mark 5 vehicles being built for Caledonian Sleeper. Seated brake, lounge and sleeper vehicles. 8 x 8-car rakes (64 vehicles) in use each night.
66 Mark 5A vehicles being built for Transpennine Express for use on Liverpool/Manchester Airport - Scarborough/Middlesbrough services. 13 x 5-car rakes with seated driving trailers (Driving Trailer Standard) to be used in push-pull mode with Class 68 diesel locomotives, plus one spare Driving Trailer. 12 daily diagrams, with 1 spare set.
