Wednesday 7 October 2015

Mapping Mountains – Hill Reclassifications – Y Pedwarau


Banc Bron Derwgoed (SN 871 987) - Pedwar reclassified to 400m Sub-Pedwar  

There has been another reclassification of a Pedwar to a 400m Sub-Pedwar by surveying with the Trimble GeoXH 6000.   The hill is situated in the north-eastern part of the Pumlumon range, and is positioned to the south-west of the small communities of Llan and Bont Dolgadfan.

The hill is named Banc Bron Derwgoed (SN 871 987) and it is given 30m of drop in the 1st edition of the Y Pedwarau published by Europeaklist.  This drop figure is based on a 30.2m basic levelling survey (BLS) conducted on the 16.10.03 by Myrddyn Phillips.  This form of survey has an approximate +/- 2.5m margin of uncertainty applicable to it, and on the same day two other Pedwar hills were also measured using the BLS method, these same hills were also surveyed with the Trimble GeoXH 6000 on the same day as Banc Bron Derwgoed.  The comparison of results are given below:

Banc Bron Derwgoed:  30.2m (BLS)    27.7m (Trimble)

Llannerch yr Aur:  34.7m (BLS)    34.0m (Trimble)

Bryn y Fedwen:  32.3m (BLS)    31.5m (Trimble)


The hill can be easily accessed from a minor road to the north-west of the summit, however it is recommended to visit this hill during an extended walk and join it with its adjacent hills as the scenery of the northern Pumlumon range is majestic.

The hill was surveyed in the company of Aled Williams who had suggested the walk and is now in mourning as we have lost another Pedwar.

This now brings the overall total for the Y Pedwarau to 448 hills with five additions and four deletions since publication of the list by Europeaklist in May 2013.  The hill will be taken out of the main list and added to the 400m Sub-Pedwar list in the 2nd edition that will hopefully be published by Europeaklist.  The list of Pedwar hills is also available from the Haroldstreet website.


The full details for the hill are:

Cardinal Hill:  Foel Fadian

Summit Height:  404.2m (converted to OSGM15)

Name:  Banc Bron Derwgoed

OS 1:50,000 map:  135, 136

Summit Grid Reference:  SN 871 987

Drop:  27.7m (converted to OSGM15)


The list of additions and deletions from the main Pedwar list since the 1st edition of Y Pedwarau was published by Europeaklist are as follows:


ADDITIONS








DELETIONS






Banc Bron Derwgoed (SN 871 987) is confirmed as being reclassified to a 400m Sub-Pedwar

For details on the survey that reclassified this hill from Pedwar to 400m Sub-Pedwar status please click {here}

Myrddyn Phillips and Aled Williams (September 2015)




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