Friday, 28 July 2017

Mapping Mountains – Hill Reclassifications – Y Trichant

Ffridd Fawr (SJ 166 274) – Sub-Trichant addition

There has been a confirmation of an addition to the listing of Y Trichant due to a survey with the Trimble GeoXH 6000.  Y Trichant is the title for the hills in the 300m height band of the Twmpau (thirty welsh metre prominences and upward) and takes in all Welsh hills at or above 300m and below 400m in height that have a minimum 30m of drop, with the introduction to the re-naming of this list appearing on Mapping Mountains on the 13th May 2017.

The hill did not appear in the sub category that accompanied the original Welsh P30 lists when published on Geoff Crowder’s website, this sub category has now been standardised and named the Sub-Trichant and comprises all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.

When the sub list was standardised and drop values also added the hill was listed with c 22m of drop, based on the 335m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated bwlch height of c 313m based on interpolation of bwlch contours between 310m – 320m.

The name of the hill is Ffridd Fawr which was derived from local enquiry and it is situated in the  Y Berwyn group of hills and is placed in the Region of North Wales (Region A, Sub-Region A4) with its Cardinal Hill being Craig Berwyn (SJ 071 323).  The hill is positioned above the small community of Moelfre which is to the east north-east of the hill, and between Llanrhaeadr-ym-Mochnant to the west south-west and Llansilin towards the east.  
As the hill is not a part of designated open access land, permission to visit should be sought, for those wishing to do so a public footpath approaches the hill from its north-west.

The survey with the Trimble GeoXH 6000 produced a summit height of 335.1m (converted to OSGM15) and a bwlch height of 312.4m (converted to OSGM15), with these values giving this hill 22.7m of drop, which confirms its addition to Sub-Trichant status and the total in the Y Trichant and the Twmpau will be updated accordingly.

The full details for the hill are:

Cardinal Hill:  Craig Berwyn

Summit Height:  335.1m (converted to OSGM15)

Name:  Ffridd Fawr

OS 1:50,000 map:  125

Summit Grid Reference:  SJ 16688 27439  
Drop:  22.7m (converted to OSGM15)

Ffridd Fawr (SJ 166 274) confirmed as an addition to the Sub-Trichant

Myrddyn Phillips (July 2017)

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