In September 1984, The Railway Magazine reported that British Railways’ ageing fleet of diesel multiple-units were to be replaced by modern vehicles.
AT long last, British Railways ageing fleet of diesel multiple-units is in sight of replacement by modern vehicles. Some of the first replacements are the “l41“ class of four-wheel diesel railbus now at work in West Yorkshire, soon to be joined by 100 similar class “142” units.
As regards bogie d.m.us, invitations to tender for 100 class “150” units have been issued to British Rail Engineering Limited and Metro-Cammell Limited (RM July 1984, page 284). following the authorisation of prototypes from these two manufacturers. The first of two of these prototype “150″s. three—car unit No. 150 001, was handed over to Bob Reid, Chairman of BRB. at a ceremony at the York Works of BREL on June 8.
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Each of the two BREL prototypes comprises three vehicles: Driving Motor Second “A” (DMS”A”): Motor Open Second (MOS): and Driving Motor Second “B” (DMS“B”). All three vehicles are powered, and up to four units can be coupled together to operate in multiple; the units are designed to be compatible with other BREL d.m.us now being built (for example the class “I42” railbus) but they will not operate in multiple with earlier builds, such as the class “141”. The class “150” is a derivative of the class “2l0” d.e.m.u. and the “317” and “455” e.m.us, using wellproven structural techniques from the highly successful MkIlI coach—the lightest and most cost-effective InterCity coach in Europe.
Bodyside construction incorporates IZ zinc-coated steel skin and IZ rails and pi]- lars, joined using resistance spot welding. The small heat input involved in this technique minimises distortion. The structure is designed to give optimum strength to weight ratios.
All joints on the mild steel underframe are arc-welded. Roof design is also derived from the MkIII coach. The roof is corrugated mild steel and does not employ purlins.
An end-load of 150 tonnes at coupler level can be withstood by the structure, which meets all UIC end-load requirements. The vehicle is designed for a 30-year fatigue life, and the driving cars weigh approximately 35 tonnes in working order. Sound insulation is ensured by the use of an anti-drumming compound which is applied as a spray within the body structure. This is supplemented by fibreglass thermal and accoustic insulation in the bodyside floor and roof. Bogie design also reduces the level of track sound transmitted to the passenger saloons.
Each vehichle of unit No. 150 001 is powered by a Cummins “NT-855-R5” engine rated at 285 h.p. (213 kW) at 2,100 r.p.m., driving a Voith “211” hydraulic transmission via a cardan shaft. Gmeinder final drive assemblies are provided. The BRELbuilt production units will be fitted with this power and transmission equipment, which has been proven in use on d.m.us operated by the Netherlands Railways.
The second BREL-built prototype threecar unit has a Rolls-Royce “Eagle” type “C6.280I-IR” engine in each vehicle, rated at 280 h.p. This drives a Self Changing Gears Limited “R500” fully-automatic gearbox via a cardan shaft. The final drive assemblies on this unit are also supplied by SCG. Maximum operating speed is 75 m.p.h. for both units and auxiliary power is supplied by two alternators driven by a splitter gearbox from the engine.
Bogies are developed from the successful “BT13” family. Secondary suspension is by air-bags, and incorporates a levelling valve for maintaining standard floor height. Airoperated tread brakes using composition blocks are fitted, tread, rather than disc brakes, having been specified by BR. The system incorporates SAB cylinders and slack adjusters.
Fully automatic BSI couplers. incorporating electrical and pneumatic connections. are fitted, similar to those on class ‘“317“ e.m.us. at the outer ends of the driving vehicles. enabling units to be coupled and uncoupled without the need for shunting staff to go between the vehicles. Within each set the cars are linked by semi-permanent bar couplers. The BS1 couplers are from Bergische-Stahl Industrie, of Remscheid, West Germany.
Every vehicle has two double sliding doors each side for passenger use. The doors are under the control ofthe guard but can be transferred to passenger operation. Double-glazed window units are fitted. incorporating tinted glass to reduce glare and condensation. Hinged twin-hopper lights above the windows afford additional ventilation in warm weather.
Waste heat from the engines is used by the heating system. Heating units are mounted under the seats. and warm air distribution is assisted by fans. The system is supplemented by an oil—fired water heater. which also acts as an engine pre-heater. Ventilators are incorporated in the roof. and air circulation is further aided by the hinged twin-hopper lights above the windows.
Lighting is undiffused 4-ft. fluorescent tubes placed longitudinally in two rows in each vehicle. as in the class “-155” e.m.us. Passenger gangways affording full access between cars are provided within each set. Although connections are not fitted in the end cabs for access between adjacent units. the design is adaptable to provide this facility at a later date if required. Seating saloons are segregated from the doorway vestibules by draught screens incorporating toughened glass. except the bulkheads of the parcels area. which are solid. This lockable parcels area is provided in the DMS”B“ vehicle of each set and tipup seats are fitted to give extra passenger accommodation during times of heavy traffic.
The prototype trains feature two different types of seats in the main saloons. The second unit is fitted throughout with bus-type seats and includes a mix of unidirectional seating and facing bays. Seating capacity is 352 with a crush loading capacity of 617. The non-driving vehicle of the first unit has BR standard inner-suburban scating similar to that used on the Southern Region class “-155” e.m.us. with bus-type seats on the driving vehicles. This gives a seating capacity of 239. All seats are fitted with removable covers for ease of cleaning and maintenance.
The design. however, is sufficiently flexible to accept a wide range of alternative seating from bench seats to InterCity standard. and the ratio of seats to standing space can be varied to suit individual operating requirements.
A modular toilet compartment is fitted on one of the DMS“A“ vehicles ofeach unit incorporating flush toilet and washing facilities.
Layout of the driver’s cab is similar to that used on other recent multiple—unit trains. and incorporates a wheelslip detection device. Automatic sliding doors give crew access via transverse vestibules adjacent to the cab. which has no external doors. eliminating draughts. Cab-to-cab communication and a public—address system are fitted and provision exists to install train-to-signalbox radio at a later date if required. The design can also be modified for one-person operation.
There is a destination indicator above the centre windscreen of the driving vehicles and. if specified by the BR Director of Provincial Services. swinging plug doors could be fitted to later builds instead of sliding doors. which would eliminate the need for door pockets. It is inten-ded to exhaustively test both the BREL and Metro-Cammell class “150” prototypc units all over the BR system. to learn as quickly as possible of any desirable modifications. which can then be incorporated into the later production units.
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