Friday, 24 September 2021

Mapping Mountains – Significant Name Changes – 100m Twmpau


Quarry Field (SJ 183 147) 

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 and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

Quarry Field (SJ 183 147)

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 100m Twmpau by Myrddyn Phillips

The hill is adjoined to the Carnedd Wen group of hills which are situated in the south-eastern part of North Wales (Region A, Sub-Region A4), and it is positioned with the Afon Efyrnwy (River Vyrnwy) and the A495 road to its north-west, the A490 road to its east and minor roads to its north and south, and has the village of Meifod towards the west south-west. 

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

After 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 under the point (Pt. 109m) notation with an estimated c 22m of drop, based on the 109m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 87m bwlch height, based on interpolation of 10m contouring between 80m – 90m. 

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

This hill was the fourth of five hills visited during the day, all of which formed separate walks.  When descending from its summit I was fortunate to meet the local farmer; Richard Morris of Cil Farm.  During our conversation Richard explained that he grew up in this community and farmed all his adult life, but only took over the land that comprises this hill three years ago.  He told me that it has no individual name but the upper field where the summit is situated is known as Quarry Field. 

Richard Morris

Therefore, the name this hill is now listed by in the 100m Twmpau is Quarry Field and this was derived from local enquiry. 

 

The full details for the hill are: 

Group:  Carnedd Wen 

Name:  Quarry Field

Previously Listed Name:  Pt. 109m 

OS 1:50,000 map:  125

Summit Height:  109.5m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SJ 18332 14741 (Trimble GeoXH 6000)

Bwlch Height:  86.6m (LIDAR)

Bwlch Grid Reference:  SJ 18549 14551 (LIDAR)

Drop:  22.9m (Trimble GeoXH 6000 summit and LIDAR bwlch) 

 

Myrddyn Phillips (September 2021)

 

 

 

 

 

 

 

 

  

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