The British Rail Class 302 (initially AM2) was a class of electric multiple units (EMUs) that was introduced between 1958 and 1960 for outer suburban passenger services on the London, Tilbury and Southend line (LTS). This class of multiple units was constructed with Mark 1 bodyshells, with slam-doors.
Overview Like all the Eastern Region AC EMUs of the period, they were equipped to operate on both 25 kV AC and the reduced 6.25 kV voltage in the inner London areas, where headroom for the overhead wires was reduced. On the LTS, the changeover point was just east of on both and Tilbury routes, with the link to being at 6.25kV AC.
Each unit was formed of four coaches, in the following formation: Driving Trailer Second Open with Lavatory (DTSOL) Motor Brake Second (MBS) Trailer Composite semi-open with Lavatory (TCsoL) Driving Trailer Second (DTS).
The initial set numbers were 201–312, later prefixed by the class number 302 upon introduction of TOPS from 1973.
The Battery Driving Trailer (BDT) and Driving Trailer (DT) were fitted with drop head buckeye couplers, with screw coupler in the guard's van; retractable buffers were also fitted only on outer ends of the BDT/DT.
Service history Public service started on 16 March 1959, with Class 302s working the first electric passenger trains between and at 25kV AC. A revised half hourly timetable started on 13 April from Colchester, with an eight-car train splitting at with one unit going to .
Some Class 302s were used for crew training in the Manchester area, before the units were introduced there in April 1960.
They were among the first electric units delivered to the Eastern Region and, although ordered for the LTS electrification, a route they were long associated with, they were used initially on the to , and lines when they were electrified in November 1960. The 302s also stepped in when electrification was extended from to Colchester in 1961 and when the units were having problems on the then new north-east London electric services. Some formations were temporarily reduced to three cars for the Enfield Town services.
The first 25 units remained on the Great Eastern Main Line for the bulk of their lives, with the remainder operating on the LTS from from 1962.
Between November 1961 and June 1962, the class suffered traction motor insulation trouble, which meant the motors had to be rewound.
One unit, 302 312, was used as a test bed for silicon rectifier technology; a Brentford transformer from 1962 to 1964 was then used to test thyristor control equipment until 1972, becoming the first electric train so fitted in the UK.
Unit 302 244 was involved in an accident in 1972 with a lorry at a level crossing at in Tilbury, after which it was decided to scrap the leading carriage, BDTC 75292. This was replaced with DTSO 77164, originally belonging to a Manchester-Bury Line . It remained like this until May 1983 when it acquired a spare BDTC, 75298, from withdrawn unit 302 250.
In 1987–88, suc units were short-formed with the removal of the trailer composite (TCsoL) and based at Ilford EMU Depot for work on the Great Eastern (GE) lines:
Unitnumber Formernumber BDTCO MBSO DTSO 302434 302234 75207 61093 75081 302439 302239 75287 61098 75212 302459 302259 75307 61118 75232 302462 302262 75310 61121 75235 302494 302294 75342 61210 75267 302497 302297 75345 61213 75282
Following the privatisation of British Rail, ownership of the last 30 units passed to Eversholt Rail Group with all units being leased by LTS Rail.
The run-down of Class 302s started in 1984, with the majority of units being phased out when were introduced on to the LTS in 1988. The last 30 units were withdrawn by 1998, with the introduction of s in 1997 and some s in 1998.
Electrical equipment
Electrical equipment was supplied by English Electric, with the majority of equipment being interchangeable with units.
There were three main electrical systems: Control, which operated at 110 volts DC, provided by nickel iron alkaline secondary cells Auxiliary 250 V AC from the tertiary winding of the main transformer, which provided power to the battery charger which was also rectified to power the main compressor Power circuits derived from the secondary winding of the main transformer at 1,500 V AC.
The primary winding of the transformer was designed to operate on either 6.25 or 25 kV with voltage sensing equipment fitted to ensure the correct arrangement of primary windings for a given voltage. An incorrect voltage selection device was fitted to both Classes 302 and 308 stock so that, if the primary winding were connected for 6.25 kV when supplied with 25 kV, the air blast circuit breaker manufactured by Brown Boveri would remain closed, but the pantograph would be lowered. Should this happen, the transformer would require changing and an overhaul, as well as possibly other equipment, due to flashover damage.
The transformer was also protected by a Buchholz relay, which monitored any gas build-up within the cooling/insulating oil, as the acetylene (ethyne) gas generated is highly explosive. All Class 302 and 308 stocks were fitted with Stone Faiveley pantographs for current collection from the overhead line. A particular oddity of Eastern/Anglian region EMU stock was the fitting of fibreglass snow shields between the pantograph and the supporting insulators.
One member of the class, 302 302, was experimentally fitted with thyristor control in the early 1970s. After the experiment, it was converted back to the original tap changer control, although the guard's van remained slightly different internally.
Refurbished units
Upon refurbishment, the trailer coaches were fitted with B5 bogies for both driving ends, along with conversions of the Battery Driving Second Open (BDTSOL) to a Battery Driving Trailer Composite Open (BDTCOL); this took place after having moved the first-class accommodation to a position over the Westinghouse CM38 main compressor, which was noisy and caused vibration. Driving Standard Compartments were converted to Driving Standard Open DTSOs, having removed the compartments for an open layout. The centre trailer had B4 bogies fitted, with the Trailer Composite Semi Open (TCSOL) design converted to Trailer Standard Open (TSOL). The motor coach retained its Gresley-derived bogies after refurbishment, with compartments removed for an open layout with a guards van. All 30 units would also receive gangway connections between cars within the unit.
The vehicles were insulated originally with blue asbestos, which was removed and sealed during refurbishment between 1982 and 1984; some of the compartments were removed and reconfigured to open saloons.
Units that received the original facelift with just Motor Brake Second (MBS) and the Driving Trailer Second (DTS), having their compartments removed for an open layout with the (TCSOL) not receiving any layout changes and keeping the Gresley bogies were: 202, 204, 205, 213, 215, 216, 217, 218, 220, 225, 226, 227, 228, 231, 232, 234, 236, 239, 245, 251, 252, 254, 259, 261, 262, 263, 274, 277, 279, 280, 283, 284, 285, 292, 293, 297, 298, 299, 300, 301, 303, 304, 307, 308 and 311.
The 30 units that received the full refurbishment, and would last until withdrawal of the class from service on the LTS, were:
Unitnumber Formernumber BDTCO MBSO TSO DTSO Unitnumber Formernumber BDTCO MBSO TSO DTSO 302201 75085 61060 70060 75033 302216 75100 61075 70075 75063 302202 75086 61061 70061 75034 302217 75190 61076 70076 75064 302203 302263 75311 61122 70122 75236 302218 75191 61077 70077 75065 302204 75088 61063 70063 75036 302219 75192 61078 70078 75066 302205 75089 61064 70064 75037 302220 75193 61079 70079 75067 302206 75090 61065 70065 75038 302221 75194 61080 70080 75068 302207 302310 75358 61226 70226 75283 302222 75195 61081 70081 75069 302208 302308 75356 61224 70224 75281 302223 302293 75341 61209 70209 75266 302209 75093 61068 70068 75041 302224 75197 61083 70083 75071 302210 75094 61069 70069 75042 302225 75198 61084 70084 75072 302211 75095 61070 70070 75043 302226 75199 61085 70085 75073 302212 75096 61071 70071 75044 302227 302277 75325 61193 70193 75250 302213 75097 61072 70072 75060 302228 75201 61087 61087 75075 302214 302304 75352 61220 70220 75277 302229 75202 61088 70088 75076 302215 75099 61074 70074 75062 302230 302232 75205 61091 70091 75079
Class 302/9: non-passenger conversions
The sub-classification 302/9 was used for seven non-passenger carrying conversions.
Parcels units Units 302 990-993 were reduced to three cars and converted for use as Royal Mail parcels units, with the addition of bodyside roller shutter doors; they were repainted into their red and yellow livery.
Unitnumber BDTPMV Formernumber MPMV Formernumber DTPMV Formernumber 302990 68100 (75084) 68020 (61090) 68207 (75082) 302991 68101 (75221) 68021 (61067) 68208 (75217) 302992 68102 (75220) 68022 (61227) 68209 (75218) 302993 68105 (75078) 68023 (61222) 68213 (75074)
Departmental sandite units Units 302 996-998 were also reduced to three cars and were used as departmental sandite rail treatment units, later being reclassified as .
Unitnumber DT Formernumber MB Formernumber DT Formernumber (937)996 ADB977598 (75080) ADB977599 (61073) ADB977600 (75061) (937)997 ADB977601 (75211) ADB977602 (61228) ADB977603 (75035) (937)998 ADB977604 (75077) ADB977605 (61062) ADB977606 (75070)
Liveries When introduced, the units were outshopped in plain British Rail (BR) EMU suburban green livery, with the early lion and wheel crest on the MBS. In 1962, a small yellow end became mandatory for all units. In the mid-1960s, Rail Blue, also known as Monastral blue, was applied to 112 members of the fleet. From 1968, a full yellow end became mandatory to increase visibility for permanent way staff on the track.
From 1982, when refreshed units were released from the works, they were painted in the then-standard BR blue and grey livery. The first member of the class to receive Network SouthEast livery was 302 217 by 1987, which was the sole example until 1990–1993 when it was applied to the 30 remaining class members. Unrefurbished unit 302 207, later renumbered 302 200, received the original green livery with a small yellow panel in 1987.
Preservation
Two driving trailers, 75033 and 75250, which belonged to units 302 201 and 227, are preserved at Mangapps Railway Museum, near Burnham-on-Crouch, in Essex. These units have been repainted into BR overall blue with yellow ends; they are still in very good condition, including working destination scrolls, the seats in BR colours and the Network SouthEast maps. The rest of the fleet has been scrapped since withdrawal in late 1999.
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