It was on 23 Nov 1993, and the details are listed on the site below,
about a third of the way down the page. It seems the Central Line was
affected until 30 Nov, a total af almost 7 days
http://www.parliament.the-stationery...rittens-1.html
I *told* Clive he should have kept those Underground News back issues.
In the January 1994 issue, three items from the Daily Telegraph are
summarized:
| [Thu] 25.11.93 - The biggest power failure and evacuation in LT's
| history occurred yesterday. More than 20,000 commuters had to be
| rescued from stranded trains trapped in tunnels when power failed
| at 07.10 on the eastern sections of the Central, Circle, District,
| Hammersmith & City, Metropolitan and East London Lines; the back-up
| supply failed 20 minutes later. Services were restored to all lines
| except part of the Central, by mid-afternoon, when LT engineers
| traced the failure to a cable fault near Newbury Park station.
| However, as the evening peak was building up, power failed again
| stranding six trains between Leytonstone and Stratford. As a result
| LUL has cancelled services east of Liverpool Street today.
| [Fri] 26.11.93 - The Central Line east of Liverpool Street will
| again be shut this morning because of random electrical short-
| circuiting. Electricians are examining cabling up to 70 years old
| to trace the problem; they spent Tuesday night replacing worn
| equipment on the Hainault loop. The earlier failure which stranded
| 29 trains in tunnels for up to three hours was caused by burn-outs
| elsewhere; two damaged 22,000 volt cables at Mile End and a back-up
| supply have been fixed only for the system to fail again. LUL has
| warned that because of the intermittent failures the problem is
| difficult to trace and part of the Central Line may remain closed
| until Monday.
| [Tue] 30.11.93 - Central Line services should be normal today after
| a "sleuthing" exercise traced the main electrical fault to 56-year-
| old burned cabling at Lots Road power station; random failures
| lasting up to 7 hours accounted for most of the week-long period
| of delays for travellers. Prof. Brian Mellitt, LUL Engineering
| Director, has said that at least 35% of the power cabling should
| have been replaced 15 years ago. LUL estimates that the failures
| cost £2 million in lost revenue, compensation claims, and paying
| for 24-hour engineering work.
In the February 1994 issue there is summarized a Times article, also
dated Tuesday, November 30, 1993:
The Government has admitted that the Tube network is under-funded,
in the aftermath of a week of electrical problems which is expected
to cost about £2 million. Steven Norris, the junior minister, said
the Government was spending record amounts on the railway but agreed
it was still not enough. After the power was restored, re-opening
of the Central Line between Gants Hill and Redbridge was further
delayed by flooding because the pumps were not working during the
power failure. The article features a picture of the offending
burnt-out cable.
Finally, in the March 1994 issue is a Quality of Service Sub-Committee
report, this too dated Tuesday, November 30, 1993. It gives the fol-
lowing explanation and chronology:
# The series of failures which started on 23.11.93 was still subject
# to investigation, and LUL could only give a provisional explanation.
# Problems had arisen from three faults which occurred concurrently -
# (a) a transformer failure at Newbury Park, (b) a cable failure
# between Mile End and Greenwich, which had not yet been located
# exactly, and (c) a fault in an earthing cable at Lots Road. The
# sequence of events had been:
# Tuesday 23rd November - A transient supply failure occurred in the
# evening, but services had been restarted after a relatively short
# delay. A temporary supply was switched in.
# Wednesday 24th November - In the morning, the main supply failed,
# but the temporary supply failed too. A major power failure immob-
# ilised much of the Central Line and all the sub-surface parts of
# the system simultaneously. 20,000 passengers were evacuated from
# trains stalled between stations, and as many as 300,000 were af-
# fected in all (12% of daily users). An earth fault occurred at
# Newbury Park, which damaged cabling at Lots Road. Tripping the
# earth fault de- tector at Mile End switch house caused the entire
# switchboard to cut out. The supplies to the other sections were
# isolated and restored, and attention was concentrated on finding
# the fault in the 98km of cable supplying the Central Line.
# Thursday 25th November - Power was restored in the late evening.
# Friday 26th November - Central Line power failed again. The defect-
# ive cable at Lots Road was located 25ft. above ground. Tracing the
# fault had been immensely time-consuming, and 17 gangs were needed
# to make checks and tests. Bus shuttle services were operated over
# the trainless sections of the Central Line.
# Tuesday 30th November - Services were restored on the Central Line
# east of Stratford. No absolute guarantee could be given that some-
# thing similar would not happen again. The Central Line modernis-
# ation project included renewal of the cables serving the line
# itself, substations and switchgear. Work on the western half was
# complete, and the rest was due to be commissioned in July 1994.
# However, work on the Mile End feeder point, and the Northern Line
# power supply (which was as old as the Central Line's) did not rank
# high enough to be funded in the foreseeable future...
--
Mark Brader | "If one were to believe the bulk of our mail, one
Toronto | would conclude that about every part of our anatomy
| (even those we don't possess) is the wrong size..." --LWN