Mapping Mountains – Hill Reclassifications – 200m Twmpau

Copa’r Frân (SJ 206 703) – 200m Sub-Twmpau addition

There has been confirmation of an addition to the list of 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from a Leica GS15 bwlch survey conducted by John Barnard and Graham Jackson and a Trimble GeoXH 6000 summit survey conducted by Myrddyn Phillips with assistance from Mark Trengove. 

Copa'r Frân (SJ 206 703)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 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. 

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Copa’r Frân and this was derived from local enquiry, and it is adjoined to the Moel y Gamelin group of hills, which are situated in the north-eastern part of North Wales (Region A, Sub-Region A2), and it is positioned with a minor road to its south-west and the B5123 road to its east, and has the town of Yr Wyddgrug (Mold) towards the south south-east.

When the original 200m 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-evaluated and it was listed with an estimated c 22m of drop, based on an estimated c 285m summit height and an estimated c 263m bwlch height, with both heights based on interpolation of 5m contouring that appear on the Ordnance Survey 1:25,000 Explorer map. 

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

This hill has now been accurately surveyed with its bwlch using the Leica GS15 and its summit with the Trimble GeoXH 6000, resulting in its confirmation as a 200m Sub-Twmpau. 

The Trimble GeoXH 6000 gathering data at the summit of Copa'r Frân

Therefore, the confirmation of the addition of this hill to 200m Sub-Twmpau status is due to a Leica GS15 bwlch survey and a Trimble GeoXH 6000 summit survey, resulting in a 286.1m summit height and a 265.7m bwlch height, with these values giving this hill 20.4m of drop, which is sufficient for it to be classified as a 200m Sub-Twmpau. 

 

The full details for the hill are: 

Group:  Moel y Gamelin 

Name:  Copa’r Frân 

OS 1:50,000 map:  117

Summit Height:  286.1m (converted to OSGM15, Trimble GeoXH 6000) 

Summit Grid Reference:  SJ 20624 70354 (Trimble GeoXH 6000) 

Bwlch Height:  265.7m (converted to OSGM15, Leica GS15) 

Bwlch Grid Reference:  SJ 20803 70065 (Leica GS15) 

Drop:  20.4m (Trimble GeoXH 6000 summit and Leica GS15 bwlch) 

 

Myrddyn Phillips (August 2022)