On 26th November 2022, a sinkhole appeared in a field just to the south of Finedon.
The sinkhole was above the long abandoned Thingdon Iron Ore Mine, last worked by the Wellingboro’ Iron Co. Ltd in 1947/1948.
It can be seen to be over a major junction on the abandonment plan:
The long straight level running north-west to south-east is the main haulage level, operated by an endless haulage system.
Update March 2023
Some photographs of the mine tunnels near the sinkhole have been sent to the NVMSG, and are shown here:
It is clear from these images that eventually the tunnel roof will fail and collapse onto the tunnel floor. Above the ironstone is a clay layer with no strength, but above that is the estuarine limestone. This limestone will hold the roof for some time as it is relatively strong, however it will eventually also fail and the collapse will then migrate to the surface.
Because of the larger span of tunnel roof at junctions, they are more likely to collapse, although clearly weakness in the strata may well dominate.
It is also clear from these images that this Finedon Sinkhole will not be the last!