Mapping Mountains – Hill Reclassifications – Y Trechol – The Dominant Hills of Wales

Cae Ffwyn Uchaf (SN 588 005) – Dominant reclassified to Lesser Dominant

There has been a reclassification to the listing of Y Trechol – The Dominant Hills of Wales, with the summit height, its location, drop and status of the hill confirmed by LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of Cae Ffwyn Uchaf

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

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.

Prior to LIDAR analysis this hill was listed with 50.75% dominance based on a c 34m drop value, with a 67m summit spot height on the Ordnance Survey 1:50,000 Landranger map and an estimated bwlch height of c 33 based on interpolation of bwlch contouring between 30m – 35m.

The bounded land where the summit of this hill is situated is named Cae Ffwyn Uchaf on the Tithe map and this is the name the hill is now listed by.  The hill is adjoined to the Mynydd Penlle’rcastell group of hills, which are situated in the western part of South Wales (Region C, Sub-Region C1), and is positioned with the B4296 immediately to its east with the M4 and the Afon Lliw beyond, and has the town of Gorseinon towards the south.

 

If wanting to visit the hill permission to do so should be sought as the summit area is not a part of designated open access land, for those wishing to do so the summit is positioned relatively close to a B road which could give access towards the summit from its east.

The reclassification of Cae Ffwyn Uchaf to Lesser Dominant status is due to LIDAR analysis conducted by Myrddyn Phillips.   The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

The DTM LIDAR analysis gives the hill the following details:

Name:  Cae Ffwyn Uchaf

Summit Height:  66.6m

Summit Grid Reference:  SN 58825 00532

Bwlch Height:  36.0m (natural bwlch)

Bwlch Grid Reference:  SN 59731 00951 (natural bwlch)

Drop:  30.6m

Dominance:  45.90%

LIDAR bwlch image of Cae Ffwyn Uchaf

Therefore, the 66.6m LIDAR analysis for the summit position at SN 58825 00532 and the 36.0m LIDAR analysis for the bwlch position at SN 59731 00951 gives this hill 30.6m of drop and 45.90% dominance, which is insufficient for its continued Dominant status, with LIDAR also giving a 65.9m height at SS 58625 99765 which is to the old listed summit of this hill.

 

LIDAR image of the old listed summit at SS 58625 99765

The full details for the hill are:

Group:  Mynydd Penlle’rcastell

Name:  Cae Ffwyn Uchaf

OS 1:50,000 map:  159

Summit Grid Reference:  SN 58825 00532 (LIDAR)

Summit Height:  66.6m (LIDAR)

Bwlch Grid Reference:  SN 59731 00951 (LIDAR, natural bwlch)

Drop Summit to Bwlch:  30.6m (LIDAR)

Drop Bwlch to ODN:  36.0m (LIDAR, natural bwlch)

Dominance:  45.90% (LIDAR)

Myrddyn Phillips (February 2019)

Mapping Mountains – Summit Relocations – 30-99m Twmpau and Y Trechol – The Dominant Hills of Wales

Cae Ffwyn Uchaf (SN 588 005)

There has been a Summit Relocation 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, drop and status of the hill confirmed by LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of Cae Ffwyn Uchaf

The criteria for the two listings that this summit relocation 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 name of the bounded land where the summit of this hill is situated is Cae Ffwyn Uchaf and this was derived from the Tithe map, and it is the name this hill is now listed by.  The hill is adjoined to the Mynydd Penlle’rcastell group of hills, which are situated in the western part of South Wales (Region C, Sub-Region C1), and is positioned with the B 4296 immediately to its east with the M 4 and the Afon Lliw beyond, and has the town of Gorseinon towards the south.

As the summit of this hill is not a part of designated open access land permission to visit should be sought, for those wishing to do so it is positioned relatively close to a B road which could give access towards the summit from its east.

When this hill was originally listed as a P30 and published in the 30-99m height band of hills on Geoff Crowder’s v-g.me website, and drop values later added it was listed with c 34m of drop based on the 67m spot height that appears on the Ordnance Survey 1:50,000 Landranger map at SN 586 998 and an estimated c 33m bwlch height.

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

The position of this hill’s summit was re-evaluated when the Ordnance Survey Interactive Coverage Map hosted on the Geograph website became available online, this map showed a 67m spot height positioned at SN 588 005.

Extract from the Ordnance Survey Interactive Coverage Map hosted on the Geograph website

However, it was only with the advent of LIDAR that the high point of this hill could be confirmed, with the summit height produced by LIDAR analysis being 66.6m at SN 58825 00532, with LIDAR giving 65.9m at SS 58625 99765 to the position of the previously listed summit.  The position of the new listed summit position in relation to that previously given comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

LIDAR image of the old listed summit position

The term Summit Relocations applies to any listed hill whose summit meets the following criteria; where there are a number of potential summit positions within close proximity and the highest point is not where previously given, 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, or when the summit of the hill is in a different field compared to where previously given, or when the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary that is judged to be a relatively recent man-made construct.  As heights on different scaled Ordnance Survey maps are not consistent the height given on the 1:25,000 Explorer map is being prioritised in favour of the 1:50,000 Landranger map for detailing these relocations.

The summit height produced by LIDAR analysis is 66.6m and is positioned at SN 58825 00532, this position is close to where the 67m spot height appears on the Ordnance Survey Interactive Coverage Map hosted on the Geograph website, and it is approximately 750 metres north from where the previously listed summit is positioned.  With the caveat that the previously listed summit has a covered reservoir positioned at or close to it, and as this is considered a relatively recent man-made construct it is not considered as a part of this hill’s height.

   

The full details for the hill are:

Group:  Mynydd Penlle’rcastell

Name:  Cae Ffwyn Uchaf

OS 1:50,000 map:  159

Summit Height:  66.6m (LIDAR)

Summit Grid Reference (new position):  SN 58825 00532 (LIDAR)

Bwlch Height:  36.0m (LIDAR, natural bwlch)

Bwlch Grid Reference:  SN 59731 00951 (LIDAR, natural bwlch)

 

Drop:  30.6m (LIDAR)

Dominance:  45.90% (LIDAR)

My thanks to Aled Williams for helping to decipher the Tithe name given to the bounded land where the summit of this hill is situated

Myrddyn Phillips (January 2019)

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

Cae Ffwyn Uchaf (SN 588 005)

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, drop and status of the hill confirmed by LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of Cae Ffwyn Uchaf

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 Mynydd Penlle’rcastell group of hills, which are situated in the western part of South Wales (Region C, Sub-Region C1), and is positioned with the B 4296 immediately to its east with the M 4 and the Afon Lliw beyond, and has the town of Gorseinon towards the south.

Since this hill appeared in the original Welsh 30-99m P30 list published on Geoff Crowder’s v-g.me website its summit has been relocated, with it originally appearing under the name of Pen yr Heol, with an accompanying note stating; Name from road at summit.

Pen yr Heol

67m

SS586998

159

164/178

Height from 1987 1:50000 map. Name from road at summit

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 what I thought to be a road, and which is in fact a district of Gorseinon, as that for 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.

As the summit of this hill comprises bounded land the details for it were examined on the Tithe map.  The term Tithe map is generally given to a map of a Welsh or English parish or township and which was prepared after the 1836 Tithe Commutation Act.  This act allowed tithes to be paid in cash rather than goods.  The Tithe maps gave names of owners and occupiers of land in each parish and importantly for place-name research they also included the name of enclosed land.  This enclosed land is usually based on a field system, however not every field is given a name, but many are and especially so in Wales.

Extract from the Tithe map

The enclosed land where the summit of this hill is situated is given the number 273 on the Tithe map, this can be cross referenced against the apportionments; it is these apportionments that give the name of the owner or occupier of the land as well as the name of the land.  The land where the summit of this hill is situated is named as Cae ffrenuchaf [sic] in the apportionments, with the details on the Tithe map appearing in the parish of Llandeilo Tal-y-bont in the county named as Glamorganshire.

Extract from the apportionments

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

The full details for the hill are:

Group:  Mynydd Penlle’rcastell

Name:  Cae Ffwyn Uchaf

Previously Listed Name:  Pen yr Heol 

OS 1:50,000 map:  159

Summit Height:  66.6m (LIDAR)

Summit Grid Reference:  SN 58825 00532 (LIDAR)

Bwlch Height:  36.0m (LIDAR, natural bwlch)

Bwlch Grid Reference:  SN 59731 00951 (LIDAR, natural bwlch)

 

Drop:  30.6m (LIDAR)

Dominance:  45.90% (LIDAR)

My thanks to Aled Williams for helping to decipher the Tithe name given to the bounded land where the summit of this hill is situated

Myrddyn Phillips (January 2019)