Mapping Mountains – Significant Name Changes – 200m Twmpau

 

Cefn Dinas (SO 129 964) 

There has been a Significant Name Change to a hill that is listed in the 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

LIDAR image of Cefn Dinas (SO 129 964)

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

200m Twmpau - Welsh hills at or above 200m and below 300m in height with 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

The hill is adjoined to the Carnedd Wen group of hills which are situated in the south-eastern part of North Wales (Region A, Sub-Region A4), and it has minor roads to its north, south and east and the B4389 road to its west, and has the village of Betws Cedewain towards the west north-west. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was listed under the invented and transposed name of Bryn y Cefn-dinas, with an accompanying note stating; Name from coppice to the North-West.

Bryn y Cefn-dinas

223m

SO130964

136

215

Name from coppice to the North-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 a near wood and add the words Bryn y to it.  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

This was one of a number of hills visited during the hill in the company of Alex Cameron, and when descending the hill I flagged down a vehicle heading toward us on a track.  The driver was the local gamekeeper, who we had briefly talked to whilst driving up the narrow road leading to the start of the track heading up the hill.  During our conversation he confirmed that he had heard the name of Cefn Dinas used for this hill. 

Therefore, the name this hill is now listed by in the 200m Twmpau is Cefn Dinas, and this was derived from local enquiry. 

 

The full details for the hill are:

Group:  Carnedd Wen

Name:  Cefn Dinas

Previously Listed Name:  Bryn y Cefn-dinas   

OS 1:50,000 map:  136

Summit Height:  221.3m (converted to OSGM15, Trimble GeoXH 6000) 

Summit Grid Reference:  SO 12992 96463 (Trimble GeoXH 6000) 

Bwlch Height:  176.6m (LIDAR) 

Bwlch Grid Reference:  SO 13331 96892 (LIDAR) 

Drop:  44.7m (Trimble GeoXH 6000 summit and LIDAR bwlch)

 

Myrddyn Phillips (April 2021)

 

 

 

 

 

Mapping Mountains – Trimble Surveys – Carnedd Wen

 

15.09.20  Cefn Dinas (SO 129 964) 

LIDAR image of Cefn Dinas (SO 129 964)

Cefn Dinas was the twelfth of a hoped for thirteen hills for Alex during the day.  However, for me, it was only the ninth, as I had sat out the last three hills, all of which I had recently visited and Trimbled.  

The rain that had started when I was with John Watkins making place-name enquiries for the hill now listed as Square Field (SJ 070 031) was intermittently falling.  This felt refreshing when I waited beside a gate for Alex to scamper up Pen y Gaer (SJ 067 014), but by the time we parked below Crasty Frain (SO 109 983) the rain was heavier, and as Alex headed up the narrow lane to the gate giving access toward the summit I sat in the car with a boiled egg sandwich and a packet of crisps.  Alex was soon back and we now headed toward Moelywigoedd farm.  I’d recently visited this farm and met Ian Jerman who took me to the summit of his hill, we had exchanged email addresses and after processing the Trimble data I’d sent him the height of his hill and a couple of photographs of him on top.  Prior to this visit I’d emailed him and asked permission for Alex to visit, he’d replied in the affirmative, and although he was out working on the land when we arrived, I talked with his sister and as Alex headed up the hill I waited beside the car for his return. 

Alex arriving back after visiting Crasty Frain (SO 109 983)

Our route now headed southward, nearer the A483 road for the onward journey back to Welshpool Railway Station.  But before heading home we had time for at least one more hill; Cefn Dinas, which is positioned overlooking the small community of Betws Cedewain. 

Parking above the village beside the track that directed us upward toward the summit, we followed it as it swung rightward and continued around the southern flank of the hill.  As it did so, we continued on a green track to a gate which gave access to a steepening field that was adjacent to the field where the summit was positioned. 

The steepening field leading toward the summit of Cefn Dinas

We had discussed our cut-off time during the day and decided that we should be back at the car, ready to leave by 7.15pm.  As we approached the summit with the ten figure co-ordinates produced by LIDAR analysis taking us to the high point it was 5.30pm, the ascent had only taken just over 15 minutes. 

Alex at the summit of Cefn Dinas

The Trimble was soon set-up and gathering its allotted data.  During data collection Alex wandered back to the gate entrance for our downward route, whilst I stood a few metres away beside the northerly boundary fence.  I checked my watch and estimated what time we’d be back at the car and realised that if we were quick we could also visit the planned last hill, which would be the thirteenth for Alex, and tenth for me. 

Gathering data at the summit of Cefn Dinas

With the Trimble packed away we headed down, only stopping to flag down and talk with the local gamekeeper who we had briefly talked to whilst driving up the narrow road leading to the start of the track heading up the hill.  He confirmed that he had heard the name Cefn Dinas used for this hill, and then it was a walk back to the car and through Betws Cedewain toward a turning on our left where I squeezed the car next to three wheelie-bins leaving sufficient space to access the continuation of the paved lane and the track in both directions.  It was now 6.10pm and we had over an hour to ascend, survey and descend the last hill of the day; Aberbechan Wood (SO 128 950).

 

Survey Result:

 

Cefn Dinas (significant name change)  

Summit Height:  221.3m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SO 12992 96463 (Trimble GeoXH 6000)

Bwlch Height:  176.6m (LIDAR)

Bwlch Grid Reference:  SO 13331 96892 (LIDAR)

Drop:  44.7m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Dominance:  20.18% (Trimble GeoXH 6000 summit and LIDAR bwlch)

 

 

For further details please consult the Trimble Survey Spreadsheet