Rockliffe's subterranean history
Statement - April 2016
There's been some speculation in certain quarters about the stability of the ground under Rockliffe Gardens and the surrounding areas. We, as a group, have reached an informed position based on evidence from a number of sources.
Extensive research has been carried out over many years on what lies beneath Rockliffe Gardens and the surrounding area. There's no proof that the Gardens are any more susceptible to ground collapse than other sites locally. In fact much of the proven ‘old’ chalk mine, that would have been where Rockliffe Gardens are today has already collapsed in three separate and documented incidents 1904, 1937 and 1938 - meaning the ‘old’ mine is in a collapsed (and what does remain, filled) state.
We have contacted renowned industrial archaeologist Dr Per von Scheibner, who has studied the area extensively and explored many of the remaining tunnels. He states "that there is no significant evidence that any of the 'old' workings are left. In fact it is believed that nearly all of the original chalk workings were destroyed in the three collapses in the early part of the 20th Century."
There's been some speculation in certain quarters about the stability of the ground under Rockliffe Gardens and the surrounding areas. We, as a group, have reached an informed position based on evidence from a number of sources.
Extensive research has been carried out over many years on what lies beneath Rockliffe Gardens and the surrounding area. There's no proof that the Gardens are any more susceptible to ground collapse than other sites locally. In fact much of the proven ‘old’ chalk mine, that would have been where Rockliffe Gardens are today has already collapsed in three separate and documented incidents 1904, 1937 and 1938 - meaning the ‘old’ mine is in a collapsed (and what does remain, filled) state.
We have contacted renowned industrial archaeologist Dr Per von Scheibner, who has studied the area extensively and explored many of the remaining tunnels. He states "that there is no significant evidence that any of the 'old' workings are left. In fact it is believed that nearly all of the original chalk workings were destroyed in the three collapses in the early part of the 20th Century."
Rockliffe Gardens is no stranger to being in the news...
Background
In the early 1930s the Gardens were designed by Woolwich Borough Council, making use of the landscape left by years of brickworks and chalk extraction. Evidence indicates that two mines within Rockliffe Gardens were worked for chalk extraction. Within ‘Grubb’s brickworks’ the original ‘old’ mine was worked for some 43 years (1861-1904), the mine being abandoned in 1904 after a collapse. A new shaft was sunk further south and chalk continued to be extracted until 1908. It is likely that there was no great quantity of chalk extracted from the ‘new’ mine since the mine closed so soon after opening. Furthermore there’s reference to this ‘new’ mine in correspondence to Greenwich Borough Engineer in 1969 indicating chalk was extracted during two winters only.
Incidents
Incident 1, April 1904 - subsidence of 8 feet, at the western end of the brickfield. This led to the closure of the ‘old’ chalk mine.
Incident 2, September 1937 (after the Garden’s had opened) - The most significant collapse on the north west part of the gardens, coving an area 85ft x 20ft to a depth of 22ft. Much of the children’s playing area fell into the hole.
Incident 3, June 1938 - Incident occurred while investigations were underway. A council worker, Samuel Gardiner, assisting backfilling operations in boreholes, was killed when a hole opened up where he was standing in the north eastern corner of the Gardens.
Investigations
The Garden’s have historically been threatened by two different road building programs. The Ringway project and the East London River Crossing ELRC. Both schemes undertook extensive review of the chalk workings in the area. A 1983 report for the ELRC sets out the nature and conclusions of the research undertaken in the Rockliffe Gardens area:
“During 1958 Mowlems sunk a 90ft deep timber lined shaft in the north east corner of the Gardens and driving a small 6 feet high exploratory headings.”
“In the case of the third mine under Rockliffe Gardens (the other two being under Alliance Road area), it was found that an almost total collapse of the tunnels had occurred. Exploratory shafts and adits were driven from the mine’s extremities towards the centre and these failed to find any cavities other than at the ends of a few of the original tunnels in a small ancillary mine. These, together with the exploratory adits and shafts were effectively filled with ash.”
“On the evidence so far collected it would appear improbable that underground cavities, which could in the future lead to serious subsidences exist…”
Conclusions
While it is the Royal Borough of Greenwich who are responsible for the land that forms Rockliffe Gardens and it's safety and security - there appears no new evidence, no signs of subsidence, to suggest public money be spent on further detailed investigations.
In the early 1930s the Gardens were designed by Woolwich Borough Council, making use of the landscape left by years of brickworks and chalk extraction. Evidence indicates that two mines within Rockliffe Gardens were worked for chalk extraction. Within ‘Grubb’s brickworks’ the original ‘old’ mine was worked for some 43 years (1861-1904), the mine being abandoned in 1904 after a collapse. A new shaft was sunk further south and chalk continued to be extracted until 1908. It is likely that there was no great quantity of chalk extracted from the ‘new’ mine since the mine closed so soon after opening. Furthermore there’s reference to this ‘new’ mine in correspondence to Greenwich Borough Engineer in 1969 indicating chalk was extracted during two winters only.
Incidents
Incident 1, April 1904 - subsidence of 8 feet, at the western end of the brickfield. This led to the closure of the ‘old’ chalk mine.
Incident 2, September 1937 (after the Garden’s had opened) - The most significant collapse on the north west part of the gardens, coving an area 85ft x 20ft to a depth of 22ft. Much of the children’s playing area fell into the hole.
Incident 3, June 1938 - Incident occurred while investigations were underway. A council worker, Samuel Gardiner, assisting backfilling operations in boreholes, was killed when a hole opened up where he was standing in the north eastern corner of the Gardens.
Investigations
The Garden’s have historically been threatened by two different road building programs. The Ringway project and the East London River Crossing ELRC. Both schemes undertook extensive review of the chalk workings in the area. A 1983 report for the ELRC sets out the nature and conclusions of the research undertaken in the Rockliffe Gardens area:
- Le Grand Sutcliffe and Gel Ltd. Investigation and Exploration Headings circa 1938
- Messers John Mowlem Ltd, Investigation and Cavity Filling 1950s
“During 1958 Mowlems sunk a 90ft deep timber lined shaft in the north east corner of the Gardens and driving a small 6 feet high exploratory headings.”
“In the case of the third mine under Rockliffe Gardens (the other two being under Alliance Road area), it was found that an almost total collapse of the tunnels had occurred. Exploratory shafts and adits were driven from the mine’s extremities towards the centre and these failed to find any cavities other than at the ends of a few of the original tunnels in a small ancillary mine. These, together with the exploratory adits and shafts were effectively filled with ash.”
- Messrs George Wimpey 1969/70, site investigation in connection with Ringway 2 proposals
“On the evidence so far collected it would appear improbable that underground cavities, which could in the future lead to serious subsidences exist…”
Conclusions
While it is the Royal Borough of Greenwich who are responsible for the land that forms Rockliffe Gardens and it's safety and security - there appears no new evidence, no signs of subsidence, to suggest public money be spent on further detailed investigations.
Acknowledgements
Dr Per von Scheibner
Richard O'Connor
Stephen O'Connor
Deborah O'Boyle
Penny McLean
Dr Per von Scheibner
Richard O'Connor
Stephen O'Connor
Deborah O'Boyle
Penny McLean