British Rail Class 71

Infobox Locomotive
name = British Rail Class 71
powertype = Electric


caption = E5001 at Doncaster Works.
builder = British Railways’ Doncaster Works
builddate = 1958–1960
totalproduction = 24
gauge = RailGauge|ussg|lk=on|al=on
wheeldiameter = convert|4|ft|0|in|m|3|abbr=on
tractionmotors = English Electric 532, 4 off
poweroutput = "One-hour:" convert|2700|hp|sigfig=3|abbr=on|lk=on
"Continuous:" convert|2300|hp|sigfig=3|abbr=on
tractiveeffort = convert|43800|lbf|sigfig=3|abbr=on|lk=on
whytetype = Bo-Bo
uicclass = Bo'Bo'
trainbrakes = Dual Vacuum and Air
locobrakeforce = convert|68|LTf|kN|sigfig=3|abbr=on|lk=in
electricsystem = 660–750 V DC
collectionmethod = Third Rail (mainline)
Pantograph (sidings)
length =
width =
height =
weight = convert|77.00|LT|lk=on
topspeed = convert|90|mph|km/h|0|abbr=on|lk=on
trainheating = Electric Train Heating
axleloadclass = Route availability 6
railroad = British Railways
roadnumber = E5000–E5023; later E5001–E5024; later 71001–71014
disposition = 10 rebuilt to class 74, 13 scrapped, 1 preservedThe British Rail Class 71 was an electric locomotive used on the Southern Region of British Railways, unlike most other Southern Region electric locomotives (such as the class 73s & 74s) they could not operate away from the electrified (750 V DC third rail) system.

History

As part of the BTC Modernisation plan of 1955 twenty four electric locomotives were built in 1958 for the Kent Coast main lines. They were built at the British Rail workshops in Doncaster. Numbers were originally E5000 - E5023 but the first locomotive, E5000, was renumbered E5024. They were classified type HA under the pre-TOPS scheme.

Power supply

Power collection was from a 3rd rail at 650 volts DC (Eastern & Central sections) or 750 volts DC (Western section) and control was by flywheel booster, as in the British Rail Class 70. In some yards (notably Hither Green, SE London) overhead catenary energized to 650 V DC was used. This overhead collection method was only employed where it was deemed too dangerous to have third rail with staff constantly at ground level reaching into low running areas to couple and uncouple trains. The overhead system utilised tram-style catenary and pantographs - it was not necessary to collect traction current at speed and these provided a cost saving. The pantograph retracted into a cut-out recess in the roof when not in use, to keep within the loading gauge. Certain examples were delivered new without pantographs and ran with the recess vacant for some time. Evidently supply of the overhead equipment was short. Later in life (when the catenary in yards had almost completely been removed) during overhaul the opportunity was taken, on some examples of the class, to remove the sometimes troublesome pantograph, leading again to a vacant roof recess.The danger of electrocution of staff at track level was the entire tennet behind the Southern Region/Railway adopting high-level brake pipes and control jumpers that are so distinctive of SR stock (nick-named "bagpipes"). Low-level brake pipes were still fitted to maintain the standard with other regions' stock but only used when high-level could not be. The ten redundant class 71 that were modified to become class 74 emerged from Crewe works with bagpipes in 1967/8 and 19 members of class 33 (a purely diesel powered locomotive), which were modified at Eastleigh for push-pull operation Southern Region TC units were so-fitted. In contrast, just about every other locomotive class (excepting notably classes 07, 09, 73 [all SR locomotives] & class 50) had the multiple control jumpers and brake connectors on or under the buffer beam - a perilous place to be with 750 volts inches away! Despite overhead equipment being confined to just a handful of yards, class 71 was never retro-fitted with high-level connectors.

Operations

They were mixed-traffic locomotives. Their 2700 hp packed quite a punch for a small Bo-Bo locomotive and proved useful in both theatres of heavy freight and express passenger work. Acceleration on passenger trains (even when heavily loaded) was quite astonishing. Prestigious services including the "Night Ferry" (London to Paris overnight by train-ferry) and the "Golden Arrow", the latter a Pullman service, were a mainstay of the class for many years. Reliability of the class as a whole was good - rather predictable considering the Swiss ancestry of their electrical and control gear. As more and more areas of the Eastern section were given over to the flexibilities of Multiple Unit (EMU) operation, the class found itself ousted almost completely from passenger work. During their later years their passenger duties were only the 'Night Ferry' and the nightly Victoria-Dover/Ramsgate newspaper train. Even this latter was rostered for a class 33 on Saturday nights due to the probability of engineering works enroute (see below). Their reliance on an electricity supply proved a hindrance also - much freight is moved overnight when congestion on the busy commuter corridors is low. This is also the time when engineering possessions of the track take place - the power being switched off to whole districts while this happens. Subsequently, class 71 was faced with frequent, circuitous detours purely to stay "on the juice" and an electric-only locomotive was limited in scope for inter-regional freights. The smaller class 73 had deputised for them with ease (albeit often in pairs) and they had the ability to work lines when the power was off and to run into yards on other regions where there was no electric supply of any kind - Class 71 was beginning to look (once again - see class 74) like a white elephant. With nowhere else to go, the class was doomed. When the end came, most were scrapped in fully working order, purely because they had no work. A single member of the class survives in preservation, E5001 is also in fully working order.They never received the standard SR 'raspberry' horns, retaining their melodious whistles right up until being withdrawn.

Rebuilds and renumberings

In the late 1960s, ten examples were withdrawn, eventually being converted between 1967 and 1968 at the British Rail workshops in Crewe into electro diesels. They were originally assigned the numbers E7001 - E7010 but were numbered E6101 - E6110 and classified type HB in the pre-TOPS scheme. Under TOPS the rebuilt ten became Class 74.

Because of the rebuilds there were three renumberings to fill gaps left by engines rebuilt.

The remaining fourteen became Class 71, numbered 71001 - 71014, under the TOPS scheme.

The end

The end came in 1977 when the last examples were withdrawn as a result of a motive power rationalisation. Their services were turned over to Class 73 electro diesels as part of a new timetable and better use of Class 73.

Preservation

One example is preserved. 71001 was saved by the National Railway Museum in York and has been restored as E5001.