Mapping Mountains – Significant Name Changes – 200m Twmpau and Y Trechol – The Dominant Hills of Wales

Mynydd Emroch (SS 794 907)

There has been a Significant Name Change to a hill that is listed in the 200m Twmpau and Y Trechol – The Dominant Hills of Wales, with the summit height, its location, the bwlch height and status of the hill confirmed by LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of Mynydd Emroch

The criteria for the two listings that this name change applies to are:

200m Twmpau - Welsh hills at or above 200m and below 300m in height with 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

Y Trechol - The Dominant Hills of Wales - Welsh P30 hills whose prominence  equal or exceed half that of their absolute height.  With the criteria for Lesser Dominant status being those additional Welsh P30 hills whose prominence is between one third and half that of their absolute height, with the Introduction to the Mapping Mountains publication of this list appearing on the 3^rd December 2015.

The hill is adjoined to the Cymoedd Morgannwg group of hills, which are situated in the central part of South Wales (Region C, Sub-Region C2), and it is encircled by roads with the B4282 to its north, the A4107 to its west and a minor road and the Ffrwd Wyllt stream to its south-east, and has the town of Port Talbot towards its west south-west.

This hill was first listed in the original Welsh 200m P30 list published on Geoff Crowder’s v-g.me website, under the name of Craig Emroch, which is a name appearing close to this hill’s summit on contemporary Ordnance Survey 1:25,000 Explorer maps of the day.

Craig Emroch

241m

SS793908

170

165

Clem/Yeaman. Mynydd Emroch East Top in Clem/Yeaman list. Height from 1989 1:50000 map.

During my early hill listing I paid little regard to name placement on the map, or the meaning of names and to what feature the name was appropriately applied to.  Therefore I prioritised names for listing purposes that I now understand are either inappropriate or where another name is viewed as being more appropriate.  The name of Craig Emroch refers to a rock, whilst the name of Mynydd Emroch which also appears on the Ordnance Survey 1:25,000 Explorer map and which is positioned to the west of this hill’s summit, refers to the mountain that in all probability contains the rock.  Therefore I wanted to substantiate that the name of Mynydd Emroch has been applied to this whole upland mass and not just land to the west of the summit where this name currently resides on contemporary Ordnance Survey maps.

Extract from the Ordnance Survey 1:25,000 Explorer map

Since publication of these P30 lists on Geoff Crowder’s v-g.me website there have been a number of Ordnance Survey maps made available online, some of these are historic such as the series of Six-Inch maps on the National Library of Scotland website, whilst others are current and digitally updated such as the Vector Map Local hosted on the Geograph website and which is named the Interactive Coverage Map.  One of the historic maps now available is the Ordnance Survey Draft Surveyors map which formed the basis for the first publicly available Ordnance Survey One-Inch ‘Old Series’ map, and it is the Draft Surveyors map that formed the basis for the change in this hill’s listed name.

The Draft Surveyors maps consist of the preliminary drawings made by the Ordnance Surveyor’s surveyors between the 1780s and 1840 and formed the basis for the first publicly available One-Inch map.  They were drawn at scales of six inches to the mile for areas considered of particular military significance and down to two inches to the mile for other areas.  Fair copies were then produced from these preliminary drawings to one inch to the mile and then copper plates were prepared for printing.  The Draft Surveyors maps for the whole of Wales are now available online and they form an important part in the study of Welsh upland place-names as they bridge the time frame between the late 18^th century and the mid-19^th century when the Ordnance Survey produced their first One-Inch maps, and importantly for this hill and its listed name, it is this map that shows the extended Mynydd Emroch takes in land comprising the feature that is named Craig Emroch.

Extract from the Ordnance Survey Draft Surveyors map

Therefore, the name this hill is now listed by in the 200m Twmpau and Y Trechol – The Dominant Hills of Wales is Mynydd Emroch, and this was derived from the Ordnance Survey Draft Surveyors map.

The full details for the hill are:

Group:  Cymoedd Morgannwg

Name:  Mynydd Emroch

Previously Listed Name:  Craig Emroch 

OS 1:50,000 map:  170

Summit Height:  241.9m (LIDAR, natural summit)

Summit Grid Reference:  SS 79401 90728 (LIDAR, natural summit)

Bwlch Height:  122.2m (LIDAR)

Bwlch Grid Reference:  SS 79380 91805 (LIDAR) 

Drop:  119.7m (LIDAR)

Dominance:  49.50% (LIDAR)

Myrddyn Phillips (May 2019)