The ground underwent its most extensive redevelopment to date in 1955, at a total cost of £28,500. The previously sloping pitch was levelled, the terracing that occupied part of the Gordon Road side of the ground replaced, and new covered accommodation, known as the Stanley Stand, erected between the Rainham End and Gordon Road Stand. The first floodlights were erected in 1963, at a cost of over £14,000, but this was to be the last significant development work at Priestfield for over thirty years. By the early 1980s the capacity of the ground was listed as 22,000, although this was reduced to 19,000 when the Gordon Road Stand was closed for safety reasons. In 1987, a clock was erected at the corner of the Rainham End and the Stanley Stand, dubbed the Lord Sondes Clock in honour of Henry Milles-Lade, 5th Earl Sondes, a member of the club's board of directors. The clock was removed during later stadium redevelopment work.