Mapping Mountains – Hill Reclassifications – Humps

Old Radnor Hill (SO 251 587) – Subhump deletion

This is the eighteenth in a series of Hill Reclassification posts that detail hills whose status has been altered in the listing of the Humps (HUndred Metre Prominences) through map study and / or surveys that I have conducted.

The remains of Old Radnor Hill (SO 251 587)

This and forthcoming posts are retrospective as many of these hill reclassifications were initiated from studying the Ordnance Survey enlarged mapping that is hosted on the Geograph website, or in this instance from a survey with the Trimble GeoXH 6000, and for the reclassifications that affected the Humps the survey of this hill took place on the 11.01.14.

The listing of Humps was published in book format by Lulu in 2009 and entitled More Relative Hills of Britain, its author; Mark Jackson gives credit to a number of people who contributed toward the formation of this list, these include; Eric Yeaman, Alan Dawson, Clem Clements, Rob Woodall, Bernie Hughes, Pete Ridges and others.  When the list was published in book format there were 2987 Humps listed with their criteria being any British hill that has 100m or more of drop, accompanying the main list is a sub category entitled Subhumps, with the criteria being any British hill that has 90m or more and below 100m of drop.

More Relative Hills of Britain by Mark Jackson

The details for the reclassification appear below:

There has been a deletion from the listing of the Humps (HUndred Metre Prominences) instigated by a survey with the Trimble GeoXH that was conducted on the 11.01.14.

The hill had previously been listed as a Hump with a 327m summit height and 110m of drop, due to the hill being quarried its drop value was reduced in April 2011 to c 100m based on a reduction in its estimated summit height to c 317m, with it still retaining its Hump status.  The hill was then reclassified to a Subhump in January 2013 based on a 222m bwlch height which gave the hill c 95m of drop.  As well as the summit being reduced in height due to quarrying, there is a road cutting to the east of the hill which if taken as a part of the hill’s drop would increase this value.  The hill was subsequently surveyed with the Trimble GeoXH 6000 resulting in a 312.6m (converted to OSGM15) summit height and a 222.7m (converted to OSGM15) height to what was judged to be the highest remaining natural ground of the critical bwlch, and a 215.6m (converted to OSGM15) height to the road cutting, resulting in a 89.9m and 97.1m drop value respectively. 

The hill is adjoined to the Fforest Glud range of hills and is situated overlooking the A 44 road to its east which increases its prominence if this road cutting is included as a part of the drop value, and has the small community of Walton towards the north-north-east and Old Radnor towards the north-west.

The deletion of this hill from Subhump status based on the survey taken to what was judged to be the highest remaining natural ground of the critical bwlch and was accepted by Mark Jackson and it was deleted from the listing of the Humps on 13.09.14.

Gathering data with the Trimble GeoXH 6000 at what was judged to be the highest remaining natural ground of the critical bwlch

The full details for the hill are:

Name:  Old Radnor Hill

Summit Height:  312.6m (converted to OSGM15)

OS 1:50,000 map:  148

OS 1:25,000 map:  201

Summit Grid Reference:  SO 25122 58775 (as listed in the Humps, with the Trimble survey taken to SO 25135 58770)

Drop:  89.9m (converted to OSGM15)

Myrddyn Phillips (October 2017)