Mapping Mountains – Hill Reclassifications – Y Pedwarau - The 400m Hills of Wales

Cwm Cynnydd Bank (SO 053 724) - 400m Sub-Pedwar reclassified to Pedwar

There has been a reclassification to the listing of the Y Pedwarau with a 400m Sub-Pedwar being reclassified to Pedwar status due to analysis of LIDAR data by Aled Williams.  The 400m Sub-Pedwarau is one of five categories of sub hills that accompany the main Y Pedwarau list, with the criteria for 400m Sub-Pedwar status being all Welsh hills at or above 400m and below 500m in height with 20m or more and below 30m of drop, with the criteria for Pedwar status being all Welsh hills at or above 400m and below 500m in height with a minimum 30m of drop.

The hill is situated in the Pegwn Mawr group with its Cardinal Hill being Brondre Fawr Hill (SO 041 783) and is placed in the Region of Mid and West Wales (Region B, Sub-Region B1), and is positioned between the small communities of Bwlch y Sarnau to the north-west and Abaty Cwm Hir (Abbey Cwmhir) to the south.

The summit of the hill is situated in conifer plantation but the hill can be accessed via forestry tracks from a number of directions as these encircle the upper part of the hill.  The forestry track towards the north-east and also the south-west of the summit gives access to a forest ride that passes within a few metres and to the east of the high point of the hill.

The name of the hill is Cwm Cynnydd Bank (previously listed in Y Pedwarau as Pt. 444m, Cwmcynydd Bank) and prior to the analysis of LIDAR data and its subsequent listing as a Pedwar the hill had been listed as a 400m Sub-Pedwar with c 27m of drop based on the 444m spot height that appears at SO 05234 72506 on the Ordnance Survey 1:25,000 Explorer map and an estimated bwlch height of c 417m at SO 05783 72592.

As Aled was analysing other hills in the vicinity against LIDAR data, he did likewise with Cwm Cynnydd Bank.  LIDAR (Light Detection & Ranging) is highly accurate height data that is now freely available for much of England and Wales.

Aled’s analysis of LIDAR data gives the hill the following details:

Cwm Cynnydd Bank

Summit Height:  451.4m

Summit Grid Reference:  SO 05342 72437

Bwlch Height:  416.4m

Bwlch Grid Reference:  SO 05788 72576

Drop:  35.0m

Therefore, the 451.4m LIDAR data produced for the summit position at SO 05342 72437 and the 416.4m LIDAR data produced for the bwlch position at SO 05788 72576 gives this hill 35.0m of drop which is sufficient for its reclassification from a 400m Sub-Pedwar to a Pedwar.

The full details for the hill are:

Cardinal Hill:  Brondre Fawr Hill  

Summit Height:  451.4m (LIDAR data)  

Name:  Cwm Cynnydd Bank  

OS 1:50,000 map:  136, 147  

Summit Grid Reference:  SO 05342 72437  

Drop:  35.0m (LIDAR data)  

This now brings the overall total for Y Pedwarau to 445 hills with eight additions, and ten reclassifications to 400m Sub-Pedwar status since publication of the list by Europeaklist in May 2013.  The hill will be taken out of the 400m Sub-Pedwar list and added to the Pedwar list in forthcoming publications.  The list of Pedwar hills is available from the Haroldstreet website (January 2014) with all subsequent changes available via the Mapping Mountains site, with the list also having commenced publication on Mapping Mountains on the 30.01.17.

The list of additions and reclassifications from the Pedwar list since the 1^st edition of the Y Pedwarau was published by Europeaklist are as follows:

PEDWAR ADDITIONS

Y Garn (SH 758 375) 400m Sub-Pedwar reclassified to Pedwar with 31.2m drop

Cefn Perfa (SO 173 579) 400m Sub-Pedwar reclassified to Pedwar with 30.1m drop

Craig y Ganllwyd (SH 707 258) 400m Sub-Pedwar reclassified to Pedwar with 33.4m drop

Pt. 499.5m (converted to OSGM15) (SH 665 310) 400m Sub-Pedwar reclassified to Pedwar with 30.3m drop

Mynydd Poeth (SH 953 513) 400m Sub-Pedwar reclassified to Pedwar with 31.7m drop

Pt. 415.6m (LIDAR data) (SO 243 011) 400m Sub-Pedwar reclassified to Pedwar with 31.4m drop

Lan (LIDAR data) (SO 052 391) 400m Sub-Pedwar reclassified to Pedwar with 35.7m drop

Cwm Cynnydd Bank (LIDAR data) (SO 053 724) 400m Sub-Pedwar reclassified to Pedwar with 35.0m drop

PEDWAR RECLASSIFICATIONS

Pt. 422.3m (converted to OSGM15) (SO 073 822) Pedwar reclassified to 400m Sub-Pedwar with 29.0m drop

Wenallt (SN 933 571) Pedwar reclassified to 400m Sub-Pedwar with 28.3m drop

Bryn Serth (SO 147 109) Pedwar reclassified to 400m Sub-Pedwar with 25.4m drop

Banc Bronderwgoed (SN 871 987) Pedwar reclassified to 400m Sub-Pedwar with 27.7m drop

Drysgol (SN 946 744) Pedwar reclassified to 400m Sub-Pedwar with 29.2m drop

Craig y Garreg-lwyd (SH 730 427) Pedwar reclassified to 400m Sub-Pedwar with 29.9m drop

Pt. 407.7m (converted to OSGM15) (SO 180 692) Pedwar reclassified to 400m Sub-Pedwar with 28.3m drop

Twyn Disgwylfa (LIDAR data) (SS 995 959) Pedwar reclassified to 400m Sub-Pedwar with 28.8m drop

Esgair Wen (LIDAR data) (SN 807 664) Pedwar reclassified to 400m Sub-Pedwar with 29.9m drop

Carreg y Gwynt (LIDAR data) (SN 956 776) Pedwar reclassified to 400m Sub-Pedwar with 28.1m of drop

Myrddyn Phillips and Aled Williams (March 2017)

Mapping Mountains – Significant Name Changes – Y Pedwarau - The 400m Hills of Wales

Cwm Cynnydd Bank (SO 061 726)

There has been a Significant Name Change to a hill that is listed in the Y Pedwarau, and the following details are in respect of a hill that was surveyed with the Trimble GeoXH 6000 on the 18^th February 2016.

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

Y Pedwarau - These are the Welsh hills at and above 400m and below 500m in height that have 30m minimum drop.  The list is co-authored by Myrddyn Phillips and Aled Williams, and the introduction to the Mapping Mountains publication of this list appeared on the 30th January 2017.

The hill is a part of the Pegwn Mawr range, this group of hills is situated in the north-eastern part of Mid and West Wales, and the hill is positioned to the north north-east of the small community of Abaty Cwm Hir (Abbey Cwmhir).

Cwm Cynnydd Bank (SO 061 726)

The hill appeared in the 400m P30 list on Geoff Crowder’s v-g.me website under the name of Waun Gaseg, which is a name that appeared close to the summit of the hill on Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps of the day.  

Waun Gaseg

450m

SO061726

136/147

200/214

Height from 1986 #136 1:50000 map

  

During my early hill listing I paid little regard to name placement on a map, or the meaning of names and to what feature the name was appropriately applied to.  Therefore I prioritised names for listing purposes that I now understand are inappropriate, and Waun Gaseg is such an example as this name has usually been applied by the Ordnance Survey to land beside a small stream that is below and to the south-east of this hill’s summit, whilst a number of different scaled Ordnance Survey maps position the name Cwm Cynnydd Bank as applicable to land extending toward the summit of this hill. 

Extract from the series of Ordnance Survey Six-Inch maps

Therefore, the name this hill is now listed by in Y Pedwarau is Cwm Cynnydd Bank and this was derived from a number of different scaled Ordnance Survey maps, all of which place this name applicable to land that extends toward this hill’s summit.

The full details for the hill are:

Group:  Pegwn Mawr

Name:  Cwm Cynnydd Bank

Previously Listed Name:  Waun Gaseg 

Summit Height:  454.9m (converted to OSGM15)

OS 1:50,000 map:  136, 147

Summit Grid Reference:  SO 06116 72668 

Drop:  83.9m (converted to OSGM15)

For details on the survey of Cwm Cynnydd Bank

Myrddyn Phillips and Aled Williams (October 2016)

Mapping Mountains – Significant Height Revisions – Y Pedwarau

Cwm Cynnydd Bank (SO 061 726)

There has been a Significant Height Revision to a hill that is listed in the Y Pedwarau that was initiated by a survey with the Trimble GeoXH 6000, with the survey that resulted in this height revision being conducted on 18^th February 2016.  The criteria for Pedwar status being all Welsh hills at or above 400m and below 500m in height that have 30m minimum drop.

The name of the hill is Cwm Cynnydd Bank and it is situated in the hills of the Pegwn Mawr range which is positioned in mid Wales and the survey was conducted during a walk taking in one Trichant and three Pedwar hills.

The hill is situated in woodland, but can be accessed from open hillside and forest tracks to within a few metres of its summit, which is positioned in mature conifer plantation just to the north of a broad path.  The hill is situated to the north of the small community of Abaty Cwm Hir (Abbey Cwmhir) and to the south-east of the small community of Bwlch y Sarnau.

Prior to the survey with the Trimble GeoXH 6000 the hill was listed as a Pedwar with a 450m summit height taken the spot height that appears on the Ordnance Survey 1:50,000 Landranger map.  This height equates to the old imperial height of 1,477ft that appears on the Ordnance Survey 1:25,000 Historical Map which originates from the series of Ordnance Survey old Six-Inch maps.  This height appears near to or on the broad path that gives access to this hill’s summit and which traverses its broad north-east to south-west ridge.

When surveying this summit I waited a long time for the Trimble GeoXH 6000 to attain its 0.1m accuracy level before data should be logged, during this time I assessed the lay of land around the summit and tried to keep warm.  I estimated the summit of the hill to be approximately 3m higher than the path where the centralised imperial height appears on the old Six-Inch map. 

Therefore this hill’s new summit height is 454.9m (converted to OSGM15) which is 4.9m higher than its previously listed height of 450m and 14.9m higher than the uppermost 440m ring contour that appears on Ordnance Survey 1:25,000 Explorer maps.

The full details for the hill are:

Cardinal Hill:  Brondre-fawr Hill

Summit Height:  454.9m (converted to OSGM15)

Name:  Cwm Cynnydd Bank

OS 1:50,000 map:  136, 147

Summit Grid Reference:  SO 06116 72668

Drop:  83.9m (converted to OSGM15)

Gathering data at the summit of Cwm Cynnydd Bank (SO 061 727) which resulted in this hill's significant height revision

For details on the survey that significantly revised the summit height of this hill

Myrddyn Phillips and Aled Williams (February 2016)