Mapping Mountains – Significant Name Changes – 100m Twmpau

 

Bron y Gaer (SN 699 326) 

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 derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Bron y Gaer (SN 699 326)

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 that have 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 100m Twmpau by Myrddyn Phillips

The hill is adjoined to the Mynydd Mallaen group of hills, which are situated in the central part of South Wales (Region B, Sub-Region B1), and it is positioned with minor roads to its west and south, the A40 road farther to its south and the A482 road to its east, and has the town of Llanymddyfri (Llandovery) towards the east north-east. 

The hill appeared in the original 100m Welsh P30 list on Geoff Crowder’s v-g.me website, under the transposed name of Cefn, with an accompanying note stating; Name from farm to the South.

Cefn

198m

SN697328

146/160

12/187

Name from farm to the South

 

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 transpose the name of a farm and use it for that of the hill.  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

As the summit of this hill comprises bounded land the details for it were examined on the Tithe map.  The term Tithe map is generally given to a map of a Welsh or English parish or township and which was prepared after the 1836 Tithe Commutation Act.  This act allowed tithes to be paid in cash rather than goods.  The Tithe maps gave names of owners and occupiers of land in each parish and importantly for place-name research they also included the name of enclosed land.  This enclosed land is usually based on a field system, however not every field is given a name, but many are and especially so in Wales. 

Extract from the Tithe map

The enclosed land where the summit of this hill is situated is given the number B275 on the Tithe map, this can be cross referenced against the apportionments; it is these apportionments that give the name of the owner or occupier of the land as well as the name of the land.  The land where the summit of this hill is situated is named as a part of Bron y Gaer farm in the apportionments, with the details on the Tithe map appearing in the parish of Llansadwrn and in the county named as Carmarthenshire. 

Extract from the apportionments

Therefore, the name this hill is now listed by in the 100m Twmpau is Bron y Gaer and this was derived from the Tithe map. 

 

The full details for the hill are: 

Group:  Mynydd Mallaen 

Name:  Bron y Gaer

Previously Listed Name:  Cefn 

OS 1:50,000 map:  146, 160

Summit Height:  199.7m (LIDAR) 

Summit Grid Reference:  SN 69948 32662 & SN 69950 32662 (LIDAR) 

Bwlch Height:  166.5m (LIDAR) 

Bwlch Grid Reference:  SN 69362 32822 (LIDAR) 

Drop:  33.2m (LIDAR) 

 

Myrddyn Phillips (April 2022)

 

 

 

 

 

 

Mapping Mountains – Summit Relocations – 100m Twmpau

Bron y Gaer (SN 699 326) 

There has been confirmation of a Summit Relocation 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 derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Bron y Gaer (SN 699 326)

The criteria for the list that this summit relocation applies to are: 

100m Twmpau - Welsh hills at or above 100m and below 200m in height that have 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 100m Twmpau by Myrddyn Phillips

The name the hill is listed by is Bron y Gaer and this was derived from the Tithe map, and it is adjoined to the Mynydd Mallaen group of hills, which are situated in the central part of South Wales (Region B, Sub-Region B1), and it is positioned with minor roads to its west and south, the A40 road farther to its south and the A482 road to its east, and has the town of Llanymddyfri (Llandovery) towards the east north-east. 

When the original Welsh 100m P30 list was published on Geoff Crowder’s v-g.me website, this hill was listed with a 198m summit height positioned at SN 697 328, based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map. 

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

Since the original publication of the Welsh P30 lists on Geoff Crowder’s v-g.me website there have been a number of 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 were digitally updated such as the Ordnance Survey Vector Map Local that was hosted on the Geograph website and which was entitled the Interactive Coverage Map, whilst others are current and digitally updated such as the interactive mapping on the Magic Maps and WalkLakes websites. 

The details for this hill were re-assessed when the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map became available online.  This mapping had many spot heights not on other publicly available Ordnance Survey maps and for this hill it had a 199m summit spot height positioned at SN 69968 32669, therefore the listed summit position of this hill was relocated. 

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of Bron y Gaer (SN 699 326)

The summit height produced by LIDAR analysis is 199.7m and is positioned at SN 69948 32662 and SN 69950 32662, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are: 

The term Summit Relocations applies to when the high point is positioned in a different field, to a different feature such as a conifer plantation, within a different map contour, a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is considered a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist. 

Therefore, the summit height produced by LIDAR analysis is 199.7m and is positioned at SN 69948 32662 and SN 69950 32662, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and is approximately 270 metres south-eastward from where the previously listed summit is positioned. 

 

The full details for the hill are: 

Group:  Mynydd Mallaen

Name:  Bron y Gaer 

OS 1:50,000 map:  146, 160

Summit Height:  199.7m (LIDAR) 

Summit Grid Reference (New Position):  SN 69948 32662 & SN 69950 32662 (LIDAR) 

Bwlch Height:  166.5m (LIDAR) 

Bwlch Grid Reference:  SN 69362 32822 (LIDAR) 

Drop:  33.2m (LIDAR) 

 

Myrddyn Phillips (April 2022)

 

 

  

Mapping Mountains – Hill Reclassifications – 100m Twmpau

Bron y Gaer (SN 699 326) – 100m Sub-Twmpau reclassified to 100m Twmpau

There has been confirmation of a reclassification to the list of 100m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Bron y Gaer (SN 699 326)

The criteria for the list that this reclassification applies to are: 

100m Twmpau – Welsh hills at or above 100m and below 200m in height that have 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 100m Twmpau by Myrddyn Phillips

The name the hill is listed by is Bron y Gaer and this was derived from the Tithe map, and it is adjoined to the Mynydd Mallaen group of hills, which are situated in the central part of South Wales (Region B, Sub-Region B1), and it is positioned with minor roads to its west and south, the A40 road farther to its south and the A482 road to its east, and has the town of Llanymddyfri (Llandovery) towards the east north-east. 

When the original 100m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 category. 

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with an estimated c 30m of drop, based on the 198m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 168m bwlch height based on interpolation of 10m contouring between 160m – 170m. 

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

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.  

Therefore, the confirmation of the reclassification of this hill from 100m Sub-Twmpau status is due to LIDAR analysis, resulting in a 199.7m summit height and a 166.5m bwlch height, with these values giving this hill 33.2m of drop, which is sufficient for it to be classified as a 100m Twmpau. 

 

The full details for the hill are: 

Group:  Mynydd Mallaen 

Name:  Bron y Gaer 

OS 1:50,000 map:  146, 160

Summit Height:  199.7m (LIDAR) 

Summit Grid Reference:  SN 69948 32662 & SN 69950 32662 (LIDAR) 

Bwlch Height:  166.5m (LIDAR) 

Bwlch Grid Reference:  SN 69362 32822 (LIDAR) 

Drop:  33.2m (LIDAR) 

 

Myrddyn Phillips (April 2022)