Mapping Mountains – Hill Reclassifications – Y Trichant – The 300m Hills of Wales

 

Blaen Pathiog (SN 927 820) – Sub-Trichant reclassified to Trichant

There has been confirmation of a reclassification to the list of Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

LIDAR image of Blaen Pathiog (SN 927 820)

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

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant, with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Blaen Pathiog and it is adjoined to the Pumlumon group of hills, which are situated in the north-western part of Mid and West Wales (Region B, Sub-Region B2), and it is positioned with the A470 road to its south-east, and has the town of Llanidloes towards the north-east. 

When the original 300m height band of Welsh P30 hills was published on Geoff Crowder’s v-g.me website, this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 category.  

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

After the P30 lists were standardised, and interpolated heights and drop values also included, this hill was listed with an estimated c 33m of drop based on the 379m summit spot height that appeared on the Ordnance Survey Vector Map Local that was hosted on the Geograph website and an estimated c 346m bwlch height, based on interpolation of 10m contouring between 340m – 350m.  The 379m summit spot height has latterly also appeared on the online mapping available on the Magic Maps website.  

Extract from the Magic 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. 

The result produced by LIDAR analysis gives this hill a 376.1m summit height, and as the summit has now been surveyed with the Trimble GeoXH 6000 it is this result that is being prioritised for listing purposes.

The Trimble GeoXH 6000 gathering data at the summit of Blaen Pathiog

Therefore, the confirmation of the reclassification of this hill from Sub-Trichant status is due to LIDAR analysis and a subsequent Trimble GeoXH 6000 survey, resulting in a 376.3m summit height and a 343.3m bwlch height, with these values giving this hill 33.1m of drop, which is sufficient for it to be classified as a Trichant. 

 

The full details for the hill are: 

Group:  Pumlumon 

Name:  Blaen Pathiog 

OS 1:50,000 map:  136

Summit Height:  376.3m (converted to OSGM15, Trimble GeoXH 6000)     

Summit Grid Reference:  SN 92775 82001 (Trimble GeoXH 6000) 

Bwlch Height:  343.3m (LIDAR) 

Bwlch Grid Reference:  SN 92760 81765 (LIDAR) 

Drop:  33.1m (Trimble GeoXH 6000 summit and LIDAR bwlch)

                                                        

Myrddyn Phillips (December 2020)

 

 

 

 

 

 

Mapping Mountains – Hill Reclassifications – Y Trichant – The 300m Hills of Wales

 

Mountain (SJ 235 555) – Sub-Trichant addition

There has been confirmation of an addition to the list of Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from detail on contemporary maps produced from Ordnance Survey data and LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Mountain (SJ 235 555)

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

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant, with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017. 

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

The name the hill is listed by is Mountain, and this was derived from the Tithe map, and it is adjoined to the Moel y Gamelin group of hills, which are situated in the north-eastern part of North Wales (Region A, Sub-Region A2), and it is positioned with the A5104 road to its west and the B5430 road to its south, and has the village of Treuddyn towards the north-north-east. 

When the original 300m height band of Welsh P30 hills was published on Geoff Crowder’s v-g.me website, this hill was not included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for this sub category. 

After the P30 lists were standardised, and interpolated heights and drop values also included, this hill was listed with 25m of drop based on the 334m summit spot height and the 309m bwlch spot height that appear on the Ordnance Survey 1:25,000 Explorer map. 

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. 

Therefore, the confirmation of the addition of this hill to Sub-Trichant status is due to detail on contemporary maps produced from Ordnance Survey data and LIDAR analysis, resulting in a 334.0m summit height and a 309m bwlch height, with these values giving this hill 25m of drop, which is sufficient for it to be classified as a Sub-Trichant.

 

The full details for the hill are: 

Group:  Moel y Gamelin 

Name:  Mountain 

OS 1:50,000 map:  117

Summit Height:  334.0m (LIDAR)                                                           

Summit Grid Reference:  SJ 23575 55527 (LIDAR) 

Bwlch Height:  309m (spot height) 

Bwlch Grid Reference:  SJ 23660 55008 (spot height) 

Drop:  25m (LIDAR summit and spot height bwlch) 

 

Myrddyn Phillips (December 2020)

 

 

 

 

 

 

 

 

Mapping Mountains – Hill Reclassifications – Y Trichant – The 300m Hills of Wales

Pt. 366m (SJ 207 568 & SJ 205 575) – Sub-Trichant addition

There has been an addition to the list of Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from detail on contemporary maps produced from Ordnance Survey data.

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

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant, with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13th May 2017.

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The hill is being listed by the point (Pt. 366m) notation as an appropriate name for it either through local enquiry and / or historic research has not been found by the author, and it is adjoined to the Moel y Gamelin group of hills, which are situated in the north-eastern part of North Wales (Region A, Sub-Region A2), and it is positioned with the B5430 road to its south and minor roads to its east, north and west, and has the town of Yr Wyddgrug (Mold) towards the north north-east.

When the original 300m height band of Welsh P30 hills was published on Geoff Crowder’s v-g.me website, this hill was not included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for this sub category. 

When the P30 lists were standardised, and interpolated heights and drop values also included, this hill was listed with an estimated c 19m of drop based on an estimated c 366m summit height and an estimated c 347m bwlch height, with both based on interpolation of 5m contouring with a small 365m uppermost contour given to two summits and contouring between 345m – 350m for the bwlch that appear on the Ordnance Survey 1:25,000 Explorer map.

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

Since publication of these P30 lists on Geoff Crowder’s v-g.me website there have been a number of Ordnance Survey maps made available online, some of these are historic such as the series of Six-Inch maps on the National Library of Scotland website, whilst others are current and digitally updated such as the mapping on the WalkLakes website and the Magic Maps website.

The WalkLakes website hosts an interactive map originated from the Ordnance Survey Open Data programme.  This map has many spot heights not on other publicly available Ordnance Survey maps and for this hill a 366m spot height is given to the more northerly of the two summits which is positioned at SJ 205 575.

Extract from the WalkLakes website

Another resource available online is the interactive mapping originated from Ordnance Survey data hosted on the Magic Maps website.  This mapping shows the two summits with 366m spot heights, with the more southerly positioned at SJ 207 568, which for listing purposes is regarded as the prioritised summit.

Extract from the Magic Maps website

The details for this hill were also re-assessed against the mapping on the OS Maps website.  This is the replacement for OS Get-a-map and until recent times had contours at 5m intervals which were proving consistently more accurate compared to the 5m contours that sometimes appear on the Ordnance Survey 1:25,000 Explorer map and used to appear on the online Vector Map Local.  This resulted in its bwlch height being amended and estimated as c 346m based on interpolation of 5m contouring between 345m – 350m.

Therefore, the addition of this hill to Sub-Trichant status is due to detail on contemporary maps produced from Ordnance Survey data, resulting in a 366m summit height and an estimated c 346m bwlch height, with these values giving this hill an estimated c 20m of drop, which is sufficient for it to be classified as a Sub-Trichant.

The full details for the hill are:

Group:  Moel y Gamelin

Name:  Pt. 366m

OS 1:50,000 map:  117

Summit Height:  366m (spot heights)

                                                           

Summit Grid Reference:  SJ 20774 56802 & SJ 20505 57502 (spot heights)

Bwlch Height:  c 346m (interpolation)

Bwlch Grid Reference:  SJ 20750 57920 (interpolation)

Drop:  c 20m (spot height summits and interpolated bwlch)

Myrddyn Phillips (November 2020)

Mapping Mountains – Hill Reclassifications – Y Trichant

Caer Eini (SJ 000 412) – Sub-Trichant reclassified to Trichant

There has been confirmation of a reclassification to a hill listed in the Y Trichant, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by a Trimble GeoXH 6000 survey and LIDAR analysis conducted by Myrddyn Phillips, with the former taking place on the 25^th October 2014.

Caer Eini (SJ 000 412)

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

Y Trichant – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017.

The name of the hill is Caer Eini and it is adjoined to the Arenig group of hills, which are situated in the central part of North Wales (Region A, Sub-Region A3), and it is positioned with the A494 road to its south-east, and has the town of Y Bala towards the south-west. 

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it did not meet the criteria then used for the main P30 list. 

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with 31m of drop, based on the 365m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and the 334m bwlch spot height that appears on the Ordnance Survey Vector Map Local hosted on the Geograph website and which is entitled the Interactive Coverage Map.

Extract from the Ordnance Survey Vector Map Local hosted on the Geograph website

However, it was not until the survey with the Trimble GeoXH 6000 and when 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 bwlch image of Caer Eini

The confirmation of the reclassification of Caer Eini to Trichant status is due to a survey with the Trimble GeoXH 6000 and LIDAR analysis, resulting in a 365.7m summit height and a 334.4m bwlch height, with these values giving this hill 31.3m of drop which is sufficient for it to be classified as a Trichant.

The full details for the hill are:

Group:  Arenig

Name:  Caer Eini

OS 1:50,000 map:  125

Summit Height:  365.7m (converted to OSGM15)

Summit Grid Reference:  SJ 00048 41275

Bwlch Height:  334.4m (LIDAR)

Bwlch Grid Reference:  SH 99599 41003 (LIDAR)

Drop:  31.3m (Trimble summit and LIDAR bwlch)

For details on the summit survey of this hill

Myrddyn Phillips (November 2019)

Mapping Mountains – Hill Reclassifications – Y Trichant

Pt. 368.9m (SH 991 412) – Sub-Trichant addition

There has been confirmation of an addition of a hill to the list of the Y Trichant, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis, and a Trimble GeoXH 6000 summit survey conducted by Myrddyn Phillips, with the latter taking place on the 25^th October 2014.

Pt. 368.9m (SH 991 412)

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

Y Trichant – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017.

As I do not know an appropriate name for the hill either from historic documentation or local enquiry it is being listed under the point (Pt. 368.9m) notation, and it is adjoined to the Arenig group of hills, which are situated in the central part of North Wales (Region A, Sub-Region A3), and it is positioned with the A494 road to its south-east, and has the town of Y Bala towards the south-west. 

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was not included in the Hills to be surveyed sub list that accompanied the main P30 list, as it did not meet the criteria then used for this sub category. 

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with 25m of drop, based on the 369m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and the 344m bwlch spot height that appears on the Ordnance Survey Vector Map Local hosted on the Geograph website and which is entitled the Interactive Coverage Map.

Extract from the Ordnance Survey Vector Map Local hosted on the Geograph 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 image of Pt. 368.9m (SH 991 412)

The confirmation of the addition of Pt. 368.9m to Sub-Trichant status is due to LIDAR analysis, resulting in a 368.9m summit height and a 344.2m bwlch height, with these values giving this hill 24.7m of drop which is sufficient for it to be classified as a Sub-Trichant.

The full details for the hill are:

Group:  Arenig

Name:  Pt. 368.9m

OS 1:50,000 map:  125

Summit Height:  368.9m (LIDAR)

Summit Grid Reference:  SH 99136 41259 (LIDAR)

Bwlch Height:  344.2m (LIDAR)

Bwlch Grid Reference:  SH 99216 41144 (LIDAR)

Drop:  24.7m (LIDAR)

Myrddyn Phillips (November 2019)

Mapping Mountains – Hill Reclassifications – Y Trichant

Cerrig y Ddinas (SH 754 739) – Sub-Trichant reclassified to Trichant

There has been a reclassification to a hill that is listed in the Y Trichant, with the summit height and its position initially ascertained from LIDAR analysis and the summit height, bwlch height and their locations, the drop and status of the hill subsequently confirmed by a survey with the Trimble GeoXH 6000 conducted by Myrddyn Phillips, with the latter taking place on the 22^nd May 2019.

Cerrig y Ddinas (SH 754 739)

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

Y Trichant – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017.

The name of the hill is Cerrig y Ddinas and it is adjoined to the Carneddau group of hills, which are situated in the north-western part of North Wales (Region A, Sub-Region A1), and it is positioned with the A55 road and the coast to its north, and has the town of Conwy towards the north-east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was included in the Hills to be surveyed sub list as it did not meet the criteria then used for the main P30 list; however the main P30 and accompanying sub list has now been standardised and interpolated heights and drop values also included.

When this list was standardised and interpolated heights also included this hill was listed with an estimated c 26m of drop, based on the 312m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map which was prioritised in favour of the 314m summit spot height that appears on the Ordnance Survey 1:50,000 Landranger map, and an estimated bwlch height of c 286m based on interpolation of 10m contouring on the contemporary Ordnance Survey 1:25,000 Explorer map.

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

Extract from the Ordnance Survey 1:50,000 Landranger map

The details for this hill were re-examined when the OS Maps website became available online.  This is the replacement for OS Get-a-map and has contours at 5m intervals.  The mapping on OS Maps shows this hill with bwlch contouring between 280m – 285m with an estimated height of c 284m giving this hill a drop value nearer 30m.

Extract from 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, however LIDAR coverage only takes in the summit of this hill. 

LIDAR summit image of Cerrig y Ddinas

The reclassification of this hill to Trichant status is due to a Trimble GeoXH 6000 bwlch and summit survey, resulting in a 313.5m summit height and a 283.0m bwlch height, with these values giving this hill 30.5m of drop, which is sufficient for this hill to be classified as a Trichant.

 

The full details for the hill are:

Group:  Carneddau

Name:  Cerrig y Ddinas

OS 1:50,000 map:  115

Summit Height:  313.5m (converted to OSGM15)

Summit Grid Reference:  SH 75427 73948

Bwlch Height:  283.0m (converted to OSGM15)

Bwlch Grid Reference:  SH 75140 73786

 

Drop:  30.5m (converted to OSGM15)

For details on the survey of this hill

Myrddyn Phillips (August 2019)