Showing posts with label Foel Wyddon. Show all posts
Showing posts with label Foel Wyddon. Show all posts

Wednesday, 7 June 2023

Mapping Mountains – Trimble Surveys – Pumlumon


22.04.23  Pt. 564.9m (SN 783 838) and Foel Wyddon (SN 788 836) 

Foel Wyddon (SN 788 836)

Today’s hill was another in my tantalisingly ever reducing haul of remaining Welsh 500m P15s.  Its name is Foel Wyddon and it is positioned directly above and west of Eisteddfa Gurig, therefore connecting with the Pumlumon massif.  It is also another one of those relatively recent entries to the Welsh Highlands – Uchafion Cymru list with Aled having found its qualifying credentials in 2017.

Although Aled had visited this hill there was a near sub that he wanted to investigate and so with Trimble in hand and a series of ten figure grid references noted, we set off from the top of the A44 road as it makes its way over from Llangurig in the east to Aberystwyth in the west, after of course paying the £5.00 parking fee.

There are a number of tracks that head in to the hills from the farm at the top of the road and it was one of these that conveniently lead us up toward our hills.  Except for the occasional hum of distant traffic on the road below, the only other significant sound was welcome as there was a constant backdrop of song emanating from Sky Larks.  These little birds were on form this morning, singing away across the moor land.

The track culminated at a gate leading in to forestry, the first hill we visited is listed in the Welsh Highlands as a sub and it looked as if its high point was in a section of felled conifers.  Its connecting bwlch was beside a puddle on the track and we decided to leave its survey until after visiting its summit. 

The green path and section of felled forest

A green path headed in to the forested section which as this point comprised the remains of felled trees.  To our left a small channel headed up and we opted for this instead of continuing on the main path, which if we had done so we hoped would lead to mature conifers that were easy to walk through, or alternatively we could have walked up the felled section adjacent to the mature trees. 

The small channel indicated a relatively easy way to the summit

Our route up proved relatively easy, but walking across sections of felled forest is never quick, which suited me fine this morning.  Reaching the area of the summit the high point outside of the near trees was relatively easy to pinpoint and we soon had the Trimble set up to gather data.  During data collection I followed Aled in to the trees to investigate other potential high points.  We easily reached what we considered the high point within the trees, which we judged similar in height to where the Trimble was now gathering data from.  Emerging back out of the trees and after allotted data were gathered and stored, I closed the equipment down and we retraced our route back to the gate and the track and puddle where this hill’s connecting bwlch is positioned. 

Gathering data at the summit of Pt. 564.9m (SN 783 838)

During bwlch data collection I stood beside the gate and chatted with Aled.  From this vantage point the higher Pumlumon hills were on grand display towering above our lowly position.  After five minutes of data were gathered and stored I switched the Trimble off, packed it away and we continued down our inward track to another gate which gave access to the slopes of Foel Wyddon. 

Aled setting the Trimble up to gather data at the bwlch

The Trimble GeoXH 6000 gathering data at the bwlch of Pt. 564.9m

Our onward route passed over the connecting bwlch and we quickly assessed it for its critical point before heading up to its summit.  The summit of Foel Wyddon consists of rough grass, as indeed does the hill, it has an attractive small grassed ridge and when there, we decided to gather data from two points, with the second our favoured position for its high point. 

Gathering data at the lower of the two positions surveyed for the summit of Foel Wyddon

Gathering data at the higher of the two positions surveyed for the summit of Foel Wyddon

All that remained was the descent back to its bwlch and its survey.  It was relatively easy to pinpoint its critical position and having done so we compared it to the ten figure grid reference ascertained from LIDAR analysis, before setting the Trimble up to gather its fifth and last data set of the day. 

The Trimble GeoXH 6000 gathering data at the bwlch of Foel Wyddon

Once allotted data were gathered and stored we headed back to the gate and the track leading us down to the farm house and the awaiting car at Eisteddfa Gurig. 

 

Survey Result:

 

Pt. 564.9m

Summit Height:  564.9m (converted to OSGM15)

Summit Grid Reference:  SN 78376 83898

Bwlch Height:  550.9m (converted to OSGM15)

Bwlch Grid Reference:  SN 78650 84107

Drop:  13.9m

Dominance:  2.47%

 

 

Foel Wyddon

Summit Height:  536.2m (converted to OSGM15)

Summit Grid Reference:  SN 78813 83668

Bwlch Height:  520.9m (converted to OSGM15)

Bwlch Grid Reference:  SN 78783 83858

Drop:  15.3m (Welsh Highland P15 addition)

Dominance:  2.85%

 

 

For further details please consult the Trimble Survey Spreadsheet

 

  

Sunday, 7 May 2017

Mapping Mountains – Hill Reclassifications – Welsh Highlands - Uchafion Cymru


Foel Wyddon (SN 788 836) - Welsh Highland P15 addition

There has been an addition to the listing of the Welsh Highlands – Uchafion Cymru, with the summit height, bwlch height and their locations, the drop and status of the hill initially derived from LIDAR analysis conducted by Aled Williams and confirmed by a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips and Aled Williams.

Foel Wyddon (SN 788 836).  Photo: Aled Williams

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

Welsh Highlands – Uchafion Cymru Welsh hills at or above 500m in height with 15m minimum drop, with an accompanying sub list entitled the Welsh Highland Subs, the criteria for which is all Welsh hills at or above 500m in height with 10m or more and below 15m of drop.  This list is authored by Myrddyn Phillips and Aled Williams with the Introduction to the list published on Mapping Mountains in November 2015 and the latest update relating to the list published on Mapping Mountains in January 2023.

Welsh Highlands - Uchafion Cymru by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Foel Wyddon and it is adjoined to the Pumlumon group of hills, which are situated in the north-western part of South Wales (Region B, Sub-Region B1), and is positioned with the A44 road to its south and east, and has the village of Ponterwyd towards the south-west.

When the original list that later became known as the Welsh Highlands – Uchafion Cymru was first compiled, this hill was not included as a Welsh Highland Sub and therefore remained unclassified with analysis of contemporary Ordnance Survey mapping giving an estimated c 13m of drop, based on the 535m summit spot height that appears on the 1:50,000 Landranger and 1:25,000 Explorer map and an estimated c 522 bwlch height, based on interpolation of 10m contouring between 520m - 530m.   

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

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 summit and bwlch of this hill have subsequently been surveyed with the Trimble GeoXH 6000, and it is this result that is being prioritised for this hill.

The Trimble GeoXH 6000 gathering data at the summit of Foel Wyddon

The Trimble GeoXH 6000 gathering data at the bwlch of Foel Wyddon

Therefore, the addition of this hill to Welsh Highland P15 status is due to LIDAR analysis and  subsequently confirmed by a Trimble GeoXH 6000 survey, resulting in a 536.2m summit height and a 520.9m bwlch height, with these values giving this hill 15.3m of drop, which is sufficient for it to be classified as a Welsh Highland P15.  


The full details for the hill are:


Group:  Pumlumon

Name:  Foel Wyddon

OS 1:50,000 map:  135

Summit Height:  536.2m (converted to OSGM15)

Summit Grid Reference:  SN 78813 83668 
  
Bwlch Height:  520.9m (converted to OSGM15)

Bwlch Grid Reference:  SN 78783 83858

Drop:  15.3m



For the additions, deletions and reclassifications to the Welsh Highlands – Uchafion Cymru reported on Mapping Mountains please consult the following Change Registers:












Myrddyn Phillips and Aled Williams (May 2017)