Thursday, 13 June 2019

Mapping Mountains – Significant Name Changes – 100m Twmpau


Bryn Bach (SS 903 875)

There has been a Significant Name Change to a hill that is listed in the 100m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of Bryn Bach

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

100m Twmpau - Welsh hills at or above 100m and below 200m in height with 30m minimum drop, with an accompanying sub list entitled the 100m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 100m and below 200m 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.

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 is positioned with the A4063 road and the Afon Llynfi to its south-west and the A4064 road and the Afon Garw to its south-east, and has the small community of Betws towards the south. 

This hill was first listed in the original Welsh 100m P30 list published on Geoff Crowder’s v-g.me website, under the partly invented and transposed name of Bryn Betws, with an accompanying note stating; Name from village at summit.


Bryn Betws
160c
170
166
Two points of same height - other at SS903875. Name from village at summit.


During my early hill listing I thought it appropriate to either invent a name for a hill, or use a name that appeared near to the summit of the hill on Ordnance Survey maps of the day.  My preference was to use farm names and put Pen, Bryn or Moel in front of them or as in this instance use a name of what I presumed to be a village and add the word Bryn to it.  This is not a practice that I now advocate as with time and inclination place-name data can be improved either by asking local people or by examining historic documents, through this form of research an appropriate name for the hill can usually be found.

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 One-Inch ‘Old Series’ map and it is this map that formed the basis for the change in this hill’s listed name.

The One-Inch ‘Old Series’ map was the first map that the Ordnance Survey produced, and their publication culminated from the whole of Britain being surveyed between 1791 and 1874 and the detail gathered therein produced at a scale of one inch to the mile and published in sheet format between 1805 and 1874.  The One-Inch ‘Old Series’ maps for the whole of Wales are now available online; they are also available in map format as enlarged and re-projected versions to match the scale and dimensions of the Ordnance Survey 1:50,000 Landranger series and are published by Cassini.  This series of maps form another important part in the study of Welsh upland place-names and bridge the timeframe leading up to the production of the Ordnance Survey base map of the Six-Inch series, and importantly for this hill and its listed name, it is this map that names the hill as Bryn Bach.

Extract from the Ordnance Survey One-Inch 'Old Series' map

Therefore, the name this hill is now listed by in the 100m Twmpau is Bryn Bach, and this was derived from the Ordnance Survey One-Inch ‘Old Series’ map.


The full details for the hill are:

Group:  Cymoedd Morgannwg

Name:  Bryn Bach

Previously Listed Name:  Bryn Betws 

OS 1:50,000 map:  170

Summit Height:  167.0m (LIDAR)

Summit Grid Reference:  SS 90364 87531 (LIDAR)

Bwlch Height:  135.2m (LIDAR)

Bwlch Grid Reference:  SS 90511 87849 (LIDAR)
 
Drop:  31.9m (LIDAR)


Myrddyn Phillips (June 2019)




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