Mapping Mountains – Hill Reclassifications – 30-99m Twmpau

Cae Doctor (SH 304 399) – 30–99m Sub-Twmpau reclassified to 30-99m Twmpau

There has been confirmation of a Hill Reclassification to the list of 30-99m Twmpau, with the summit height, its location, the drop and status of the hill confirmed by LIDAR analysis, with the bwlch LIDAR analysis initially conducted by Aled Williams, and a subsequent summit survey with the Trimble GeoXH 6000 conducted by Myrddyn Phillips, with the latter taking place on the 3^rd October 2018.

The summit of Cae Doctor (SH 304 399)

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

30-99m Twmpau - Welsh hills at or above 30m and below 100m in height with 30m minimum drop, with an accompanying sub list entitled the 30-99m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 30m and below 100m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

When the original Welsh 30-99m height band of P30 hills were published on Geoff Crowder’s v-g.me website this hill appeared in the accompanying Hills to be surveyed sub list as it did not meet the criteria then used for the main P30 list; however this sub list has now been standardised with drop values and interpolated heights also included in the main P30 and the accompanying sub list.

When this list was standardised with interpolated heights and drop values included this hill was listed with an estimated c 30m of drop based on the 68m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated bwlch height of c 38m based on interpolation of 10m bwlch contouring.

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

The details for this hill were reassessed when the Ordnance Survey Interactive Coverage Map hosted on the Geograph website became available online, and this map has a 37m spot height positioned at SH 30870 40378 on a minor road on the area of this hill’s bwlch, and if taken as a part of this hill’s drop this would give a value of 31m.

The locally known name for the bounded land where the summit of this hill is situated is Cae Doctor, and this is the name the hill is now listed by.  The hill is adjoined to the Pen Llŷn group of hills, which are situated in the western part of North Wales (Region A, Sub-Region A1), and it has the A497 road to its immediate south-east and the B4417 road to its north-west, and has the small town of Nefyn to the north.

The confirmation of the reclassification of Cae Doctor to 30-99m Twmpau status is due to LIDAR analysis of the bwlch conducted by Aled Williams and a summit survey with the Trimble GeoXH 6000 conducted by Myrddyn Phillips, resulting in a 67.0m summit height and a 35.8m bwlch height, with these values giving this hill 31.2m of drop which is sufficient for it to be classified as a 30-99m Twmpau.

The Trimble GeoXH 6000 gathering data at the summit of Cae Doctor (SH 304 399)

The full details for the hill are:

Group:  Pen Llŷn

Name:  Cae Doctor

OS 1:50,000 map:  123

Summit Height:  67.0m (converted to OSGM15)

Summit Grid Reference:  SH 30425 39978

Bwlch Height:  35.8m (LIDAR)

Bwlch Grid Reference:  SH 30747 40107 (LIDAR)

 

Drop:  31.2m (Trimble summit and LIDAR bwlch)

My thanks to Aled Williams for initial LIDAR analysis of this hill’s bwlch

For details of the summit survey of this hill

Myrddyn Phillips (February 2019)

Mapping Mountains – Summit Relocations – 100m Twmpau and Y Trechol – The Dominant Hills of Wales

Pt. 118.9m (SN 710 294)

There has been a Summit Relocation to a hill that is listed in the 100m Twmpau and the Y Trechol – The Dominant Hills of Wales, with the summit height, bwlch height and their locations, the drop, dominance and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Pt. 118.9m (SN 710 294)

The criteria for the two lists that this summit relocation applies to are: 

100m Twmpau - Welsh hills at or above 100m and below 200m in height with 30m minimum drop, with an accompanying sub list entitled the 100m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 100m and below 200m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

100m Twmpau by Myrddyn Phillips

Y Trechol - The Dominant Hills of Wales - Welsh P30 hills whose prominence  equal or exceed half that of their absolute height.  With the criteria for Lesser Dominant status being those additional Welsh P30 hills whose prominence is between one third and half that of their absolute height.  The list is authored by Myrddyn Phillips with the Introduction to the start of the Mapping Mountains publication of this list appearing on the 3^rd December 2015, and the list is now available inits entirety on Mapping Mountains in Google Doc format.

Y Trechol - The Dominant Hills of Wales by Myrddyn Phillips

The hill is being listed by the point (Pt. 118.9m) notation and it is adjoined to the Mynydd Du group of hills, which are situated in the southern part of South Wales (Region B, Sub-Region B5), and it is positioned with the Afon Tywi (River Towy) and the A40 road to its west, the B4069 road to its east, and has the village of Llangadog towards the south.

When the original 100m height band of Welsh P30hills were published on Geoff Crowder’s v-g.me website, this hill was included in the main P30 category and listed with a 119m summit height based on the spot height positioned at SN 72465 30422 and which appears on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map.

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

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with an estimated c 50m of drop and 42.02% dominance, based on the 119m summit spot height an estimated c 69m bwlch height, based on interpolation of 5m contouring between 65m - 70m that appeared on the OS Maps website.

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.

LIDAR analysis gives the highest ground on this hill as 119.8m positioned at SN 71062 29399.  However, this is a part of a raised field boundary and protocols dictate that as this is deemed a relatively recent man-made construct such ground is discounted from the height of a hill.

LIDAR summit image of Pt. 118.9m (SN 710 294)

The height produced by LIDAR analysis to the natural ground of this hill is 118.0m and is positioned at SN 71046 29411, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are: 

The term Summit Relocations applies when the high point of the hill is found to be positioned; in a different field, to a different feature such as in a conifer plantation,  within a different map contour, to a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is judged to be a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist.

Therefore, the height produced by LIDAR analysis to the natural summit of this hill is 118.9m and is positioned at SN 71046 29411, this position is clost to where the 119m spot height appears on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and is approximately 18 metres north-westward from where the high point of the raised field boundary is positioned.  

The full details for the hill are:

Group:  Mynydd Du

Name:  Pt. 118.9m

OS 1:50,000 map:  146, 160

Summit Height:  118.9m (LIDAR)

Summit Grid Reference:  SN 71046 29411 (LIDAR)

Bwlch Height:  69.9m (LIDAR)

Bwlch Grid Reference:  SN 72466 30393 (LIDAR)

Drop:  48.9m (LIDAR)

Dominance:  41.16% (LIDAR)

Myrddyn Phillips (February 2019)

Mapping Mountains – Significant Name Changes – 30-99m Twmpau and Y Trechol – The Dominant Hills of Wales

Cae Doctor (SH 304 399)

There has been a Significant Name Change to a hill that is listed in the 30-99m Twmpau and Y Trechol – The Dominant Hills of Wales, with the summit height, its location, the drop and status of the hill confirmed by LIDAR analysis, with the bwlch LIDAR analysis initially conducted by Aled Williams, and a subsequent summit survey with the Trimble GeoXH 6000 conducted by Myrddyn Phillips, with the latter taking place on the 3^rd October 2018.

The summit of Cae Doctor (SH 30425 39978)

The criteria for the two listings that this name change applies to are:

30-99m Twmpau - Welsh hills at or above 30m and below 100m in height with 30m minimum drop, with an accompanying sub list entitled the 30-99m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 30m and below 100m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

Y Trechol - The Dominant Hills of Wales - Welsh P30 hills whose prominence  equal or exceed half that of their absolute height.  With the criteria for Lesser Dominant status being those additional Welsh P30 hills whose prominence is between one third and half that of their absolute height, with the Introduction to the Mapping Mountains publication of this list appearing on the 3^rd December 2015.

The hill is adjoined to the Pen Llŷn group of hills, which are situated in the western part of North Wales (Region A, Sub-Region A1), and it has the A497 road to its immediate south-east and the B4417 road to its north-west, and has the small town of Nefyn to the north.

This hill was first listed in the Hills to be surveyed sub-list that accompanied the original Welsh 30-99m P30 list published on Geoff Crowder’s v-g.me website, under the invented name of Fron Oleu, with an accompanying note stating; Name from buildings to the South-West.

Fron Oleu

68m

SH305400

123

253

Name from buildings to the South-West

During my early hill listing I thought it appropriate to either invent a name for a hill, or use a name that appeared near to the summit of the hill on Ordnance Survey maps of the day.  My preference was to use farm names and put Pen, Bryn or Moel in front of them or as in this instance transpose the name of buildings that are situated near the summit of this hill.  This is not a practice that I now advocate as with time and inclination place-name data can be improved either by asking local people or by examining historic documents, through this form of research an appropriate name for the hill can usually be found.

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

I visited this hill along with Aled Williams and leaving the summit we met the local farmer who had driven up a near track to find out what we were doing.  Having explained our interest in surveying and upland place-names, Awen Roberts told us that the hill does not have an individual name but the two fields that vie for the high point of this hill are known as Cae Doctor (67.0m at SH 30425 39978) and Cae Myllt (66.9m at SH 30421 39985), with the former the higher and being named as such as a doctor lives close to its field boundary.

The summit of Cae Myllt (SH 30421 39985)

Therefore, the name this hill is now listed by in the 30-99m Twmpau and Y Trechol – The Dominant Hills of Wales is Cae Doctor, and this was derived from local enquiry.

The full details for the hill are:

Group:  Pen Llŷn

Name:  Cae Doctor

Previously Listed Name:  Fron Oleu

 

OS 1:50,000 map:  123

Summit Height:  67.0m (converted to OSGM15)

Summit Grid Reference:  SH 30425 39978

Bwlch Height:  35.8m (LIDAR)

Bwlch Grid Reference:  SH 30747 40107 (LIDAR)

 

Drop:  31.2m (Trimble summit and LIDAR bwlch)

Dominance:  46.59% (Trimble summit and LIDAR bwlch)

My thanks to Aled Williams for initial LIDAR analysis of this hill’s bwlch

For details of the summit survey of this hill

Myrddyn Phillips (February 2019)

Mapping Mountains – Trimble Surveys – Yr Wyddfa

18.10.18  Dinas Emrys (SH 606 492) and Panelau (SH 613 501)  

Dinas Emrys (SH 606 492)

Early autumnal mornings are special times amongst the hills as the chilled night air can create delicate mist formations which ebb and rise, slowly dissipating as the glow of sun increases the day’s warmth.

On my way toward the two hills I planned on visiting, I stopped my car and watched such a mist formation as it meandered its way over Llyn y Gadair, as the great bulk of Moel Hebog and its adjacent peaks acted as backdrop on this beautiful scene.

Llyn y Gadair and the great bulk of Moel Hebog

To the south the oranged hue of early morning cast out across the northern Rhinogydd, whilst ethereal wisps of mist edged their way across the expanse of foreground water.  All seemed still, only the mist slowly moved.

This scene heralded a good day ahead, and so it proved as autumnal colour mingled with morning light and distinctive and craggy tops to give me a wonderful few hours on the hill.

My first hill was Dinas Emrys, legendary place of dragons and which has association with Myrddin Emrys, the gifted youngster also known as Merlin.  I’d driven past this hill on many occasions but to my knowledge had never visited its summit, although my brother told me we once did, I have no recollection of this.

I approached from the tranquil surrounds of Craflwyn, this house is now a traditional hotel, having once been a hunting lodge and its laid out walks through Coed Craflwyn are recommended.

The path I opted for led past the dragon seat and trees moss strewn and green with quietly falling small waterfalls adding movement to an otherwise still scene.  It was beautifully tranquil in the wooded surrounds.

Coed Craflwyn

The path led toward Dinas Emrys whose wooded upper slopes still cast green as the last colour of summer clung on against the browned bracken and first colour change of autumn.

In front of me the cragged slopes of Panelau headed steeply upward and were accentuated against the low lying and gentler wooded slopes of Dinas Emrys, both at contrast and yet eloquently nested against one another.

The cragged and steep slopes of Panelau

Sun glimmered through the canopy as I followed the path toward the summit of Dinas Emrys, with the last of the morning’s mist just clinging on as blue skies dominated the scene with Moe Siabod rising as backdrop.

The summit of Dinas Emrys consists of a large rock and once I had aligned the Trimble with its highest point I stood back as it gathered its allotted data.  To my south-west Moel Hebog rose with sun and cloud casting light and shade upon its great bulk.

Moel Hebog from the summit of Dinas Emrys

It was wonderful to be on such a summit as Dinas Emrys, with stillness and sun and without a care.  Almost all I wanted was here with me.

Gathering data at the summit of Dinas Emrys

Once data were stored I packed the Trimble away and retraced my inward route back out of the woodland to a greened track leading up to an old abandoned mine.  This track gave access to the western slopes of Panelau, which abound with crags and ridges, all steep and looking decidedly rough.

I made steady progress up this rough ground looking back occasionally as Dinas Emrys sprang wooded out of a foreground of autumnal moor grass, whose beige tinged edges contrasted with the woodland below and the cultivated and reclaimed green pastures nestled at the foot of Nantgwynant.

Dinas Emrys from the ascent of Panelau

Reaching the summit I balanced the Trimble aligned with its high point and waited for the allotted data to be gathered and stored, and whilst doing so watched the play of light leading toward the darkened profile of Y Lliwedd that dominated the scene, with Yr Wyddfa almost an inconsequential elevated peak from this viewpoint.

Y Lliwedd

Gathering data at the summit of Panelau

Once summit data were stored I followed a wall down to the connecting bwlch where I again set the Trimble up to gather data.  Having taken this third data set of the day I packed the equipment away and followed another wall down toward the Afon y Cwm and the inward track I had used to access this hill’s western slopes.

On my walk back to Craflwyn and my awaiting car I called in at Hafod-y-porth and spoke with Bethan Roberts.  We stood at the front of her house and chatted about the hill I had just been up, this dominated the view, rising steeply above the farm with its cragged expanse almost hovering above in the late morning’s sun. 

Outside Hafod-y-porth with Bethan Roberts

After thanking Bethan for her time it was only a short walk down the connecting lane to the main road below, which in time took me back to Craflwyn.  A wonderful way to spend a morning.  

Survey Result:

Dinas Emrys

Summit Height:  135.6m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SH 60666 49242 (Trimble GeoXH 6000)

Bwlch Height:  96.5m (LIDAR)

Bwlch Grid Reference:  SH 60774 49401 (LIDAR)

Drop:  39.1m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Dominance:  28.86% (Trimble GeoXH 6000 summit and LIDAR bwlch)

Panelau (significant name change)

Summit Height:  337.6m (converted to OSGM15)

Summit Grid Reference:  SH 61301 50197

Bwlch Height:  287.2m (converted to OSGM15)

Bwlch Grid Reference:  SH 61341 50439

Drop:  50.4m

Dominance:  14.94%

For further details please consult the Trimble Survey Spreadsheet