A (w)hole lot of problems!Posted: May 14, 2016
The first appeared during the night of 2nd/3rd May just outside a house on a newly-built housing development in Brickfield Cottages, Plumstead.
The hole was estimated to be 60 ft deep, and its appearance caused over forty people to be evacuated from their homes whilst the cause of the hole was investigated and remedial steps were taken to ensure that the hole was stabilised before it was filled in.
After a particularly bad storm on the night of 11th/12th May an even larger hole appeared in Charlton … and a parked car nearly disappeared into it!
The car has now been successfully removed, but work on repairing the hole can only begin once the local utility suppliers (i.e. the water, electricity, and gas companies) have ensured that there has been no damage to their cables and pipework.
Yesterday another local road (Sandy Hill Road; there may be a clue to the cause of the problem in the name!) had to be closed due to a third – but much smaller hole – that has appeared in the road.
This is not a new problem in this area. On 7th April 2002 a crater 10 yards in diameter appeared on Blackheath Hill.
Initially over 100 people had to be evacuated from their homes, and it took nearly two years for the damage to be completely repaired! The cause? It is thought that the hole was caused by subsidence which was a result of old – and possibly illegal or undocumented – chalk workings.
On 1st April 1963 two large sinkholes appeared just off Plumstead Road, Woolwich.
One was large enough for a lorry to be almost completely swallowed by it when its driver failed to stop in time!
In September 1937 a large hole appeared in Rockcliffe Gardens, Plumstead, and several local children were lucky not to have fallen into it when it opened up. Similar holes appeared near the bus garage on the corner of King’s Highway and Wickham Lane, Plumstead at about the same time.
During the following Spring, a huge hole appeared in Alliance Road, Plumstead. It was 35 ft deep and 10 ft wide, and six families living in nearby houses had to be moved into Council houses in Eltham. The houses in Alliance Road were later demolished.
In May 1938, the London County Council conducted a survey of the local area and bore holes were drilled in an attempt to locate the subterranean workings that were thought to have caused the holes to appear. In June, whilst one of the holes in Rockliffe Gardens was being filled in, the ground around the hole suddenly caved in and one of the workmen – Mr Samuel Gardner – disappeared under tons of earth. It took over twenty four hours of digging before his body was recovered from 35 ft below ground.
Despite the outbreak of the Second World War, the survey continued. During 1940 three miles of tunnels were found in the area and an inspection shaft was sunk to enable permanent watch to be kept on the state of the tunnels. Little else was done until 1955, when an Act of Parliament enabled the London County Council to fill the tunnels with a mixture of water and pulverised fuel ash.
(On the face of it this does not sound like the ideal substance to infill such a large underground space, but it is worth remembering that it was only ten years after the end of the Second World War, Britain was still in a period of austerity, and fuel ash was available in large quantities as a result of the amount of coal burnt by homes and power stations.)
It is perhaps worth noting that Rockliffe Gardens, Alliance Road, King’s Highway, and Wickham Lane are all within a quarter of a mile of Brickfield Cottages. One wonders what the developers were doing building new homes in an area with a history of sinkholes!
Even earlier – in August 1585 – in nearby Mottingham it is recorded that:
‘… in a Field which belongeth to Sir Percival Hart. Betimes in the morning the ground began to sink, so much that three great Elm trees were suddenly swallowed into the Pit; the tops falling downward into the hole; and before ten of the clock they were so overwhelmed, that no part of them might be discovered, the Concave being suddenly filled with Water. The compasse of the hole was about eighty yards, and so profound, that a sounding line of fifty fathoms could hardly find or feel the bottom.‘
It would appear that South East London’s problem with sinkholes is not a new one!