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

Castell (SN 949 961) – Sub-Trichant deletion

There has been confirmation of a deletion 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 conducted by Myrddyn Phillips. 

LIDAR image of Castell (SN 949 961)

The criteria for the list that this deletion 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, and the Introduction to the Mapping Mountains publication of the list appearing on the 1^st January 2022. 

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

The name the hill is listed by is Castell and this was derived from the Ordnance Survey series of Six-Inch maps, and it is adjoined to the Pumlumon group of hills, which are situated in the northern part of South Wales (Region B, Sub-Region B1), and it is positioned with minor roads to its north and south, and the A470 road to its north-east, and has the village of Carno towards the east 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 not included in the Hills to be surveyed sub list, as it was considered not to 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 20m of drop, based on the 325m summit spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and the 305m bwlch spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map.  With the caveat that the bwlch spot height was noted to be too low. 

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

One of the resources recently available online is the mapping on the OS Maps website and the details for this hill were subsequently re-assessed against this mapping.  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 mapping had bwlch contouring between 305m – 310m, with interpolation placing the height of the bwlch as an estimated c 307m, resulting in an estimated c 18m of drop.

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 deletion of this hill from Sub-Trichant status is due to LIDAR analysis, resulting in a 323.7m summit height and a 306.4m bwlch height, with these values giving this hill 17.3m of drop, which is insufficient for it to be classified as a Sub-Trichant. 

 

The full details for the hill are: 

Group:  Pumlumon 

Name:  Castell 

OS 1:50,000 map:  136

Summit Height:  323.7m (LIDAR)                                                           

Summit Grid Reference:  SN 94917 96119 (LIDAR) 

Bwlch Height:  306.4m (LIDAR) 

Bwlch Grid Reference:  SN 94423 95831 (LIDAR) 

Drop:  17.3m (LIDAR) 

 

Myrddyn Phillips (November 2022)

 

 

  

Mapping Mountains – Significant Height Revisions – The Fours – The 400m Hills of England

Cold Stones (SE 125 636) 

There has been a Significant Height Revision to a hill that is listed in the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill prompted by Joe Nuttall who produced a summit analysis programme using LIDAR, and then confirmed by LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Cold Stones (SE 125 636)

The criteria for the list this height revision affects are:

The Fours – The 400m Hills of England.  English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list are three categories of sub hills, with this hill reclassified from the 400m Sub-Four category, the criteria for which are all English hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and the 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Cold Stones, and it is adjoined to the Whernside group of hills, which are situated in the Yorkshire Dales, and it is positioned with the B6265 road to its north and a minor road to its west, and has the town of Pateley Bridge towards the east north-east.

When the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, this hill was included as a 400m Sub-Four and listed with an estimated c 26m of drop, based on an estimated c 417m summit height positioned at SE 120 641 and a 391m col height, the latter based on the spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map, with an accompanying note stating; The one that got away, or more appropriately, the one that was quarried away, as Cold Stones was once an English 400m P30, with an imperial height of 1,403ft (427.6m) recorded for the summit on the OS 1:10,560 map, with the OS enlarged Geograph map giving a height of 391m for the extant col, thereby confirming that the hill used to have 37m of drop.  The summit has been quarried leaving the highpoint of the hill at c 417m (SE 120 641) on the western rim of the former summit dome, thereby reducing the drop to c 26m and relegating the hill to Sub-Four status. 

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. 

LIDAR summit image of Cold Stones (SE 125 636) 

LIDAR analysis gives the highest ground on this hill as 421.2m positioned at SE 12584 63663 and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey or Harvey map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR, also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 421.2m and this was derived from LIDAR analysis, this is 4.2m higher than its previously listed height of c 417m which was based on interpolation of 5m contouring that appeared on the OS Maps website. 

 

The full details for the hill are:

Group:  Whernside

Name:  Cold Stones

OS 1:50,000 map:  99

Summit Height (New Height):  421.2m (LIDAR)

Summit Grid Reference:  SE 12584 63663 (LIDAR)

Col Height:  390.8m (LIDAR)

Col Grid Reference:  SE 11773 63538 (LIDAR)

Drop:  30.4m (LIDAR)

 

Our thanks to Ronnie Bowron for bringing the details of this hill to our attention.

Myrddyn Phillips and Aled Williams (November 2022)

 

 

Mapping Mountains – Significant Name Changes – 200m Twmpau and Y Trechol – The Dominant Hills of Wales

 

Banc Bryn Amlwg (SN 547 504) 

There has been a Significant Name Change to a hill that is listed in the 200m Twmpau and 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 Banc Bryn Amlwg (SN 547 504)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 200m and below 300m 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. 

The 200m 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 in its entirety on Mapping Mountains in Google Doc format. 

Y Trechol - The Dominant Hills of Wales by Myrddyn Phillips

The hill is adjoined to the Mynydd Bach group of hills, which are situated in the western part of South Wales (Region B, Sub-Region B1), and it is positioned with a minor road to its west and the A482 road to its north-east, and has the town of Llanbedr Pont Steffan (Lampeter) towards the south-east.

The hill appeared in the original Welsh 200m P30 list on Geoff Crowder’s v-g.me website, under the transposed name of Allt Maestir, which is a prominent name that appears to the west of the summit of this hill on the Ordnance Survey 1:25,000 Explorer map.

Allt Maestir

278m

SN547505

146

199

Clem/Yeaman. Trig pillar.

 

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 a name that appears on the contemporary Ordnance Survey 1:25,000 Explorer map and which does not necessarily apply to land where the summit is situated, and use it for that of the 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

Since the original publication of the Welsh P30 lists on Geoff Crowder’s v-g.me website there have been a number of 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 were digitally updated such as the Ordnance Survey Vector Map Local that was hosted on the Geograph website and which was entitled the Interactive Coverage Map, whilst others are current and digitally updated such as the interactive mapping on the Magic Maps and WalkLakes websites.  One of the historic maps now available online is the Ordnance Survey Draft Surveyors map which formed the basis for the first publicly available Ordnance Survey One-Inch ‘Old Series’ map, and it is the Draft Surveyors map in combination with the Six-Inch map that has prompted the change in the listed name of this hill.

The Draft Surveyors maps consist of the preliminary drawings made by the Ordnance Survey surveyors between the 1780s and 1840 and formed the basis for the first publicly available One-Inch map.  They were drawn at scales of six inches to the mile for areas considered of particular military significance and down to two inches to the mile for other areas.  Fair copies were then produced from these preliminary drawings to one inch to the mile and then copper plates were prepared for printing.  The Draft Surveyors maps for the whole of Wales are now available online and they form an important part in the study of Welsh upland place-names as they bridge the time frame between the late 18^th century and the mid-19^th century when the Ordnance Survey produced their first One-Inch maps, and importantly for this hill and its listed name, it is this map that uses the name of Brynamlwg Bank, with it being listed as Banc Bryn Amlwg. 

Extract from the Ordnance Survey Draft Surveyors Map

The Ordnance Survey series of Six-Inch maps formed the base map Ordnance Survey used for many decades leading to the production of the 1:10,000 Series of maps, both have now been superseded by the digitised Master Map.  The series of Six-Inch maps are excellent for name placement and especially so compared to the contemporary Ordnance Survey 1:25,000 Explorer map, and it is the series of Six-Inch maps that places the land incorporating Allt y Maestir taking in the forested section of this hill and not where LIDAR places the summit of the hill. 

Extract from the Ordnance Survey series of Six-Inch maps

Therefore, the name this hill is now listed by in the 200m Twmpau and Y Trechol – The Dominant Hills of Wales is Banc Bryn Amlwg, and this was derived from the Ordnance Survey Draft Surveyors Map, with the land incorporating Allt y Maestir substantiated from the Ordnance Survey series of Six-Inch maps. 

 

The full details for the hill are:

Group:  Mynydd Bach

Name:  Banc Bryn Amlwg

Previously Listed Name:  Allt Maestir   

OS 1:50,000 map:  146

Summit Height:  277.7m (LIDAR) 

Summit Grid Reference:  SN 54729 50489 (LIDAR) 

Bwlch Height:  175.65m (LIDAR) 

Bwlch Grid Reference:  SN 52826 53160 (LIDAR) 

Drop:  102.0m (LIDAR) 

Dominance:  36.74% (LIDAR)

 

Myrddyn Phillips (November 2022)

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

 

Bryn y Gadair (SN 956 942) – 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 LIDAR analysis initially conducted by Aled Williams and subsequently by Myrddyn Phillips. 

LIDAR image of Bryn y Gadair (SN 956 942)

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, and the Introduction to the Mapping Mountains publication of the list appearing on the 1^st January 2022. 

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

The name the hill is listed by is Bryn y Gadair, and it is adjoined to the Pumlumon group of hills, which are situated in the northern part of South Wales (Region B, Sub-Region B1), and it is positioned with the A470 road to its north-east and a minor road to its south, and has the village of Carno towards the north.

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, as it was considered not to 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 24m of drop, based on the 396m summit spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and the 372m bwlch spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage 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 LIDAR analysis, resulting in a 396.8m summit height and a 370.7m bwlch height, with these values giving this hill 26.1m of drop, which is sufficient for it to be classified as a Sub-Trichant. 

 

The full details for the hill are: 

Group:  Pumlumon 

Name:  Bryn y Gadair 

OS 1:50,000 map:  136

Summit Height:  396.8m (LIDAR)                                                           

Summit Grid Reference:  SN 95697 94281 (LIDAR) 

Bwlch Height:  370.7m (LIDAR) 

Bwlch Grid Reference:  SN 95476 94151 (LIDAR) 

Drop:  26.1m (LIDAR) 

 

Myrddyn Phillips (November 2022)

 

 

 

 

 

 

 

Mapping Mountains – Summit Relocations – The Fours – The 400m Hills of England

 

Cold Stones (SE 125 636) 

There has been a Summit Relocation to a hill that is listed in the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill prompted by Joe Nuttall who produced a summit analysis programme using LIDAR, and then confirmed by LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Cold Stones (SE 125 636)

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

The Fours – The 400m Hills of England.  English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list are three categories of sub hills, with this hill reclassified from the 400m Sub-Four category, the criteria for which are all English hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and the 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Cold Stones, and it is adjoined to the Whernside group of hills, which are situated in the Yorkshire Dales, and it is positioned with the B6265 road to its north and a minor road to its west, and has the town of Pateley Bridge towards the east north-east.

When the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, this hill was included as a 400m Sub-Four and listed with an estimated c 26m of drop, based on an estimated c 417m summit height positioned at SE 120 641 and a 391m col height, the latter based on the spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map, with an accompanying note stating; The one that got away, or more appropriately, the one that was quarried away, as Cold Stones was once an English 400m P30, with an imperial height of 1,403ft (427.6m) recorded for the summit on the OS 1:10,560 map, with the OS enlarged Geograph map giving a height of 391m for the extant col, thereby confirming that the hill used to have 37m of drop.  The summit has been quarried leaving the highpoint of the hill at c 417m (SE 120 641) on the western rim of the former summit dome, thereby reducing the drop to c 26m and relegating the hill to Sub-Four status. 

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. 

LIDAR summit image of Cold Stones (SE 125 636)

LIDAR analysis gives the highest ground on this hill as 421.2m positioned at SE 12584 63663 as opposed to 417.3m positioned at SE 12012 64046 for the previously listed summit, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies to when the high point is positioned in a different field, to a different feature such as a conifer plantation, within a different map contour, a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is considered 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 summit height produced by LIDAR analysis is 421.2m and this is positioned at SE 12584 63663.  This position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and is approximately 600 metres south-eastward from where the previously listed summit is positioned. 

 

The full details for the hill are:

Group:  Whernside

Name:  Cold Stones

OS 1:50,000 map:  99

Summit Height:  421.2m (LIDAR)

Summit Grid Reference (New Position):  SE 12584 63663 (LIDAR)

Col Height:  390.8m (LIDAR)

Col Grid Reference:  SE 11773 63538 (LIDAR)

Drop:  30.4m (LIDAR)

 

Our thanks to Ronnie Bowron for bringing the details of this hill to our attention.

Myrddyn Phillips and Aled Williams (November 2022)