The Holmpton cliff pillbox, coordinates TA 36961 24314, was erected during WWII.
It is entered in the English Heritage Rapid Coastal Zone Assessment Survey as HM10. HM refers to the civil parish of Holmpton in the East Riding of Yorkshire. Pillbox HM10 fell over the cliff to be in pieces late autumn 2024.
In the early 1950s a Royal Observer Corps (ROC) ‘Orlit’ structure was mounted on top of the pillbox. This was the era of the Cold War. Orlit Ltd, a construction company specialising in concrete builds, including ‘prefabs’, or prefabricated housing, ceased to exist when its post-war purpose became redundant.
Sharing almost the same coordinates but having the English Heritage reference HM11, Seaside Road Holmpton was chosen by the ROC as a site for an underground monitoring post, designed to continue functioning in the event of enemy attack. It operated from February 1965 as Post 20/T.2, and closed in October 1968.
In 2001, the English Heritage Monuments Protection Programme (MPP) produced a report specifically for Cold War monuments to assess sites and recommend for protection the few that were suitable. The deteriorated ROC post at Holmpton cliff failed to be scheduled.
This location is not to be confused with the refurbished former RAF Holmpton underground bunker, occasionally open to the public (times).
In order to estimate how far inland pillbox HM10 was from the cliff when installed, the online erosion calculator may be used. The nearest measurement point is monitoring profile no. 100. Pr100 intersects the cliff line 136.08 metres north of the pillbox position. According to the calculator, from 1943 (say) to 2024 a distance of 152.12 metres was lost over 82 years, at an average rate of 1.86 metres per year. Since the pillbox fell to the beach autumn 2024, the result from the calculator may be accepted as the required distance.
The underground bunker is approximately 8 metres landward of the pillbox.