Mapping Mountains – Hill Reclassifications – Humps

Coed Mawr (SO 013 873) – Hump reclassified to Subhump

This is the twentieth 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 instigated.

The hill listed as Coed Mawr in the Humps (SO 013 873)

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 a survey with the Trimble GeoXH 6000, and for the reclassifications that affected the Humps the first survey of this hill took place on the 07.02.14.

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 reclassification to the listing of the Humps (HUndred Metre Prominences) instigated by a survey with the Trimble GeoXH 6000 and which was later confirmed by a survey with the Leica GS15.

Prior to the survey with the Trimble GeoXH 6000 Mark Jackson had listed this hill as a Hump with 125m of drop based on the 308m summit spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and the 183m bwlch spot height that appears on the Ordnance Survey 1:25,000 Explorer map.  This hill was listed as a twin as a 308m spot height also appears on Ordnance Survey maps for the hill whose summit is positioned at SN 99905 88388.

The hill appears under the name of Coed Mawr in the listing of the Humps, this name appears on current Ordnance Survey maps applicable to the woodland just to the east of the summit of the hill.  However, local enquiry and research via the Tithe map finds that the name of Y Gaer is more appropriate for this hill (see Significant Name Changes).

The hill is adjoined to the Pumlumon group of hills and is situated overlooking the A 470 road and the Afon Hafren (River Severn) which are to its east, with the small community of Llandinam at the base and to the north-east of the hill and the town of Llanidloes towards the west south-west.

This hill and its adjacent twin map heighted summit were surveyed using a Trimble GeoXH 6000 by Myrddyn Phillips on the 07.02.14 resulting in a 91.4m drop value for this hill, with its adjacent twin map heighted summit being 0.055m higher than Coed Mawr, the hill was then re-surveyed on the 02.05.14 by John Barnard, Graham Jackson and Myrddyn Phillips using a Leica GS15 and Trimble GeoXH 6000 resulting in the adjacent twin map heighted summit named as Rhos Fawr in the listing of the Humps being 0.11m higher than Coed Mawr, with this survey confirming this hill’s reclassification from prioritised Hump to Subhump status.

The reclassification of this hill from Hump to Subhump status was accepted by Mark Jackson and its new classification augmented in to the listing of the Humps on 10.05.14.

Using level and staff to determine summit position prior to surveying the hill with the Leica GS15

The full details for the hill are:

Name:  Coed Mawr (as listed in the Humps)

Summit Height:  307.1m (converted to OSGM15)

OS 1:50,000 map:  136

OS 1:25,000 map:  214

Summit Grid Reference:  SO 01352 87384

Drop:  90m (as listed in the Humps, 91.3m [converted to OSGM15] as surveyed with the Trimble GeoXH 6000)

Myrddyn Phillips (October 2017)