Monday 30 April 2018

Mapping Mountains – Hill Reclassifications – Y Pellennig – The Remotest Hills of Wales


Tap Llwyd (SH 719 065) – Pellennig addition

There has been an addition to the listing of Y Pellennig – The Remotest Hills of Wales due to a survey with the Trimble GeoXH 6000 that was instigated by a previous basic levelling survey (BLS) and summit and bwlch spot heights that appear on the Ordnance Survey Interactive Coverage Map hosted on the Geograph website. 

The criteria for qualification as a Pellennig is any Welsh hill whose summit is at least 2.5km from the nearest paved public road and the hill has a minimum 15m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and is available as a downloadable e-booklet or print-booklet version on Mapping Mountains Publications with the up-to-date master list available on the Mapping Mountains site in Google Doc format.

Tap Llwyd (SH 719 065)

The name of the hill is Tap Llwyd and prior to the Trimble GeoXH 6000 survey this hill was not classified as it had been surveyed on the 29.09.05 by Myrddyn Phillips using the BLS method as having 44ft 6̋ / 13.6m of drop.  Importantly on this day only the high point of the hill outside of its adjacent conifer plantation could be taken as its summit.  Since the BLS was conducted the Ordnance Survey Interactive Coverage Map hosted on the Geograph website has become available, and this map gives this hill 15m of drop with a 566m summit and 551m bwlch spot height.

The hill is situated in the Tarennydd group of hills with its Cardinal Hill being Tarren y Gesail (SH 710 058) and is placed in the Region of North Wales (Region A, Sub-Region A3).  The hill is positioned between the A 487 road to its east and the B 4405 road to its west and has the small community of Abergynolwyn towards its west, and has conifer plantations surrounding its western slopes and its lower eastern slopes.

As the designated border of open access land only takes in the open hillside and not the conifer plantation to the hill’s immediate west, permission to visit its summit should be sought, however common sense should prevail and as its high point is only a few metres in to what was felled forestry at the time of the Trimble survey, it is likely there would be no objection to its summit being visited.

Two points were surveyed with the Trimble GeoXH 6000 for summit position, the first being the high point of the hill outside the forestry and the second being the high point of the hill in what on the day of the survey was felled forestry, these surveys came to; 564.7m (converted to OSGM15) and 565.7m (converted to OSGM15) respectively, and with a bwlch height of 550.5m (converted to OSGM15), these values give this hill 15.3m of drop, and as the nearest paved public road is 2.875km from the summit of Tap Llwyd this hill meets the criteria for inclusion as a Pellennig hill.

The Trimble GeoXH 6000 gathering data at the summit of Tap Llwyd

The full details for the hill are:

Cardinal Hill:  Tarren y Gesail

Summit Height:  565.7m (converted to OSGM15)

Name:  Tap Llwyd

OS 1:50,000 map:  124

Summit Grid Reference:  SH 71990 06571 
  
Drop:  15.3m (converted to OSGM15)

Remoteness:  2.875km


For the additions and deletions to Y Pellennig – The Remotest Hills of Wales reported on Mapping Mountains please consult the following Change Register:







No comments: