Ffridd Cae Crydd (SN 749 976) – Welsh Sub-P15 reclassified to 200m Twmpau
There has been a reclassification to the list of The Welsh P15s and the 200m 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.
Ffridd Cae Crydd (SN 749 976) |
The Welsh
P15s – Welsh hills with 15m
minimum drop, irrespective of their height, with an accompanying sub list entitled the Welsh Sub-P15s,
with the criteria for this sub category being all Welsh hills with 14m or more
and below 15m of drop. The list is authored by Myrddyn Phillips, with the
Introduction to the list appearing on Mapping Mountains on the 10th
May 2019.
The Welsh P15s by Myrddyn Phillips |
The 200m Twmpau by Myrddyn Phillips |
Extract from the Ordnance Survey 1:25,000 Explorer map |
LIDAR image of Ffridd Cae Crydd (SN 749 976) on right and Ffridd Eithaf (SN 745 977) on left |
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.
The Trimble GeoXH 6000 gathering data at the summit of Ffridd Cae Crydd with the summit of Ffridd Eithaf in the background |
The Trimble GeoXH 6000 survey result for each summit is given below:
Ffridd Cae Crydd: 272.289m at SN 74910 97692
Ffridd Eithaf: 272.175m at SN 74578 97750
Therefore, the confirmation of the reclassification of this hill from Welsh Sub-P15 status is due to LIDAR analysis and a subsequent Trimble GeoXH 6000 survey, resulting in a 272.3m summit height and a 232.8m bwlch height, with these values giving this hill 39.4m of drop, which is sufficient for it to be classified as a 200m Twmpau.
The full details for the hill are:
Group: Pumlumon
Name: Ffridd Cae Crydd
OS 1:50,000 map: 135
Summit Height: 272.3m (converted to OSGM15, Trimble GeoXH 6000)
Summit Grid Reference: SN 74910 97692 (Trimble GeoXH 6000)
Bwlch Height: 232.8m (LIDAR)
Bwlch Grid Reference: SN 75107 97628 (LIDAR)
Drop: 39.4m (Trimble GeoXH 6000 summit and LIDAR bwlch)
Myrddyn Phillips (October 2021)
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