Mapping Mountains – Trimble Surveys – Y Berwyn

29.04.15  Gwastad Mawr (SJ 210 349) and Pen y Gwely (SJ 211 337)   

Gwastad Mawr (SJ 210 349)

One of last year’s highlights were evening walks with Mark when we stood quietly watching the sun sink in the western sky from a number of different hills.  This evening was planned to be the first of hopefully many such evening walks during this year.

Mark had suggested a walk above Glyn Ceiriog which is a valley in the north-eastern Berwyn and mid-way between where Mark was working and where I live.  We met at 4.45pm and took one car to Pont y Meibion where we left it squeezed on a grass verge at SJ 195 351.

I had contemplated wearing shorts and a thin one skin summer walking jacket, thankfully I’d opted for trousers and my spring fleece coat as conditions on the hill proved a little chilly.  As we left to walk beside the Afon Ceiriog the sun glimmered out of a partly blue sky, but greying cloud further west gave the prospect of heavy showers.

Beside the Afon Ceiriog

We struggled finding our onward path and were kindly directed on our way by a passing woman who was walking home beside the river.  Once on the right route the path curved up the hillside with attentive horses watching our upward progress.

Our onward route with attentive horses

Below us the greens of fields and trees gave a cascade of colour all merging and blending, one shade set off against another, whilst further west dark cloud showered down on the land.  Walking up toward our first hill gave a tranquil view of life in this part of Wales, Glyn Ceiriog is a beautiful valley and this evening its quiet solitude was on fine display.

Subtlety of greens

Part of the beauty of Glyn Ceiriog

Beyond the footpaths gated enclosures through Caedicws Farm is a high narrow lane which gave access to the public footpath which headed northward from beside the farm of Spring Hill toward the summit of our first hill.  I’d originally listed this hill as Pen y Gwely North Top in the P30 list that appears on Geoff Crowder’s v-g.me website and it later appeared in Mark Jackson’s Tump listing as Spring Hill, which is the name of the adjacent farm.  When compiling the 1^st edition of Y Pedwarau for Europeaklist, Aled scrutinised all Ordnance Survey maps and found the name of Gwastad Mawr on the One-Inch ‘Old Series’ sheet.  The description of the large flat (land) seems more appropriate than either the use of a supplanted North Top or that of a farm’s name.

As we headed up the footpath across the closely cropped grass the westerly wind blew in with a chill.  The Ordnance Survey spot height this hill just on the east of the north – south fence that runs from the forestry that bounds the northern part of the hill down to the farm of Spring Hill.  Previous visitors had reported the high point to be a quartz rock which is positioned within the outer confines of the forestry.  Miraculously we only waited five minutes or so for the Trimble to attain its required 0.1m accuracy before data can be logged, and once data had been gathered we retraced our steps back down the high field to the narrow lane which joined a gravelled track and which gave access toward our second and last hill of the evening; Pen y Gwely, which is a Sub-Pedwar listed with 28m of drop in the 1^st edition of Y Pedwarau published by Europeaklist.

Mark at the point surveyed for the summit of Gwastad Mawr

The point surveyed for the summit of Gwastad Mawr

Heading toward Pen y Gwely

By now the westerly grey cloud had pushed north-eastward with only the occasional spit of a rain drop falling where we were and now the evening light was starting to be illuminated with shadows cast long and the whites, greys and blacks of cloud overlapping one another in the sky above.

Gentleness of spring until the little lambykins is sent to slaughter

The gravelled track led us to a small foot stile into an adjacent field with another foot stile taking us toward the high point of Pen y Gwely which is partly immersed in fields of green and attractive reed grass, thankfully the highest point seemed to be on grass and not embedded in reed grass which would have hampered with satellite signal coverage for the Trimble.

Approaching the summit of Pen y Gwely

As the Trimble gathered data we looked out onto the higher Berwyn to our south-west and many more Pedwar hills which are planned for future evening walks.  We still had the critical bwlch of this hill to survey to see if it remained as a Sub-Pedwar or if it attained the minimum of 30m of drop to enter the main list.  However, we also hoped to make it back to Glyn Ceiriog and The Oak Y Dderwen in time for an evening meal, and as they finished serving food at 9.00pm it was going to be a close run think for us to get there in time.

Gathering data at the summit of Pen y Gwely

We reversed our route from the summit of Pen y Gwely down to the narrow lane and walked up it with the bwlch down to our right.  Mark had input the ten figure grid reference for the Ordnance Survey 416m spot height that appears at this bwlch on their enlarged mapping on the Geograph website.  This mapping also shows a number of drainage channels running west – east across the area of this bwlch.

The bwlch of Pen y Gwely

Once down amongst the reed grass and drainage channels we wandered up and down from where Mark’s hand-held GPS had taken us to and debated the lay of land.  The sun was now quickly sinking out of the evening sky and my belly desperately needed the contented feel of pub grub in it.

We walked beside one of the drainage channels for a number of minutes and discussed where the Trimble should be placed, having decided on the preferred position the Trimble was placed on grass beside the banks of one of the channels and five minutes of data were collected.

Beside one of the drainage channels with lengthening shadows heralding the sinking of the sun

We’d got about 1 ½ miles to walk back to the car and then a couple of miles drive to Glyn Ceiriog, it was now 8.10pm and we thought there was a good chance that we would make the pub for 8.50pm, we just hoped that it hadn’t been a quiet night resulting in the chef having been sent home early.  

Leaving the narrow lane and joining the gravelled track back toward the car as the sun sinks behind Springhill Wood

As we joined the track that took us down to the car the sun disappeared behind the conifers of Springhill Wood, we arrived at the car at 8.35pm and by the time that all our gear had been sorted and put in the boot we left at 8.40pm and arrived at the pub for 8.50pm, just in time for eats – YIIPPEEE! 

Survey Result:

Gwastad Mawr (significant name change)

Summit Height:  448.9m (converted to OSGM15)

Summit Grid Reference:  SJ 21055 34971

Bwlch Height:  413.5m (LIDAR)

Bwlch Grid Reference:  SJ 20287 32903 (LIDAR) 

Drop:  35.3m (Trimble summit and LIDAR bwlch)

Dominance:  7.87% (Trimble summit and LIDAR bwlch)

Pen y Gwely

Summit Height:  443.9m (converted to OSGM15)

Summit Grid Reference:  SJ 21151 33727

Bwlch Height:  414.7m (LIDAR)

Bwlch Grid Reference:  SJ 21479 34250 (LIDAR)

Drop:  29.2m (Trimble summit and LIDAR bwlch)

Dominance:  6.59% (Trimble summit and LIDAR bwlch)



For the bwlch survey of Gwastad Mawr

For further details please consult the Trimble survey spreadsheet click {here}