On the 4th January 2018, a 1.2m deep, 0.6m wide ‘’sinkhole’’ opened next to the Whitehaven – Workington railway line, near the coastal village of Harrington in Cumbria. For fears of the hole expanding and damaging the rail line, services were delayed in order to complete emergency repairs and infill the void. Initial observations have led rail engineers to speculate that a collapsed drain or coastal erosion accelerated by Storm Eleanor are the cause of the collapse. However, the correlation with known mine entries and collapses along the railway line have prompted Terrafirma to research further to see if past coal extraction may in fact be the cause.
Exploring the themes behind Sinkholes in the UK
At Terrafirma, understanding the ground is what we do best: Our CEO Tom Backhouse was recently asked to feature in Channel 5’s documentary Sinkholes to provide an expert insight into the roots behind their cause. Inevitably then, when high profile sinkholes such as those at Fontmell Close, in St Albans or in Wednesbury, causing up to six million pounds of damage and evacuating families from their homes, we ask ourselves “can sinkholes be predicted?”.
Over the last few months and years, the experts at Terrafirma have meticulously observed, understood and recorded each sinkhole as they form. Now, armed with this information, Terrafirma is proud to present a new dataset and report feature; ‘SinkholeAlert’, allowing our team to examine the common themes behind these hidden dangers.
The formation of a ‘sinkhole’ beneath a property in Wednesbury, West Midlands has received abundant coverage from the mainstream media during the last week. At Terrafirma, we have been looking into this event to try and understand more about its cause and wider context.
On May 2017, an 8-metre-deep sinkhole appeared on High Street Green, Hemel Hempstead, causing the road to be closed until around November. This is in the same neighbourhood (within 200 metres, or less than a 10-minute walk) from the 6-metre-deep sinkhole that opened up in Oatridge gardens in 2014, resulting in the evacuation of 17 people from their homes .
On 9th April 2016, a 20-foot-deep sinkhole appeared at Norwich’s Plantation Garden, causing subsidence cracks to the neighbouring hotel on Earlham Road. This is a stone’s throw away from the 1988 sinkhole which swallowed a double-decker bus. The Plantation Garden is itself an old chalk quarry, with multiple mining tunnels leading off it. It is the collapse of a mining tunnel that is thought to have caused this sinkhole.