A 1978 British Rail Southern Region report had concluded that due to the age of the equipment the re-signalling was needed by 1986. However, approval was given in 1984 after a report of three wrong-side signal failures. The re-signalling project had been planned assuming more people were available, but employees felt that the programme was inflexible and that they were under pressure to get the work done. Installation and testing was carried out at weekend during voluntary overtime, the technician having worked a seven-day week for the previous 13 weeks. The re-wiring had been done a few weeks previously, but the fault had only developed the previous day when equipment had been moved and the loose and uninsulated wire had created a false feed to a relay.