Mapping Mountains – Hill Reclassifications – Humps

Mynydd y Drum (SN 820 108) – Subhump addition

This is the twenty ninth 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 and / or on-site visits that I have conducted.

The hill listed as Mynydd y Drum (SN 820 108) in the Humps

The hill name used in this and forthcoming posts is that used in the listing of Humps, therefore individual names and their composition may not match those that are used in listings I am directly associated with.  However, I am of firm belief that listed hill names used by other authors should be respected when giving detail within other people’s lists, however inappropriate some hill names may be considered.

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 analysis of LIDAR data by Kevin McGovern and also independently by Aled Williams and then George Gradwell, resulting in an on-site visit when the hill was surveyed with the Trimble GeoXH 6000, and for the reclassifications that affected the Humps the on-site visit and survey of this hill took place on the 13.06.17.

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 reclassification to the listing of the Humps (HUndred Metre Prominences) instigated by analysis of LIDAR data by Kevin McGovern, Aled Williams and George Gradwell, resulting in an on-site visit when the hill was surveyed with the Trimble GeoXH 6000, with the latter taking place on the 13.06.17.

Prior to the survey with the Trimble GeoXH 6000 Mark Jackson had not listed this hill as it consists of waste spoil from the Nant Helen Opencast Mine that is now landscaped and it was only the analysis of LIDAR data that resulted in this hill being brought to the attention as a prospective Subhump addition.  For a detailed explanation of this hill, its height and those of adjacent hills please see Significant Height Revisions.

The hill appears under the name of Mynydd y Drum in the listing of the Humps, this is the name of the broad ridge that this and two other listed hills appear on.  When the on-site visit and survey took place I made place-name enquiries with two of the remaining six miners who still operate the opencast mine and they know the hill as Teisen Priodas, for a detailed explanation please refer to Significant Name Changes.

The hill is adjoined to the Fforest Fawr group and is situated overlooking the A 4067, A 4221 and A 4109 roads to the north-west, north-east and south-east respectively, and is positioned between the small communities of Abercraf (Abercrave) to the north and Coelbren towards the east.

This hill was surveyed using a Trimble GeoXH 6000 by Myrddyn Phillips on the 13.06.17 resulting in a 337.9m (converted to OSGM15) summit height and a 244.6m (converted to OSGM15) bwlch height, with these values giving this hill 93.3m drop, with photographs and a description of the on-site visit and survey being sent to George Gradwell who then initiated this hill’s addition as a Subhump.

The addition of this hill to Subhump status was accepted by Mark Jackson on the 14.06.17 and the listing of the Humps was updated accordingly.

The Trimble GeoXH 6000 gathering data at the summit of the hill listed as Mynydd y Drum in the Humps

The full details for the hill are:

Name:  Mynydd y Drum (as listed in the Humps)

Summit Height:  338.2m (as listed in the Humps)

OS 1:50,000 map:  160

OS 1:25,000 map:  12

Summit Grid Reference:  SN 820 108 (as listed in the Humps, SN 82013 10833 Trimble GeoXH 6000 set-up position)

Drop:  93.4m (as listed in the Humps) 

Myrddyn Phillips (November 2017)