Mapping Mountains – Trimble Surveys – Moelwyn Mawr

 

22.09.21  Bryn y Gwynt (SH 599 449) 

LIDAR image of Bryn y Gwynt (SH 599 449)

This hill entered the ranks of P30s in 2018 due to LIDAR analysis conducted by Aled Williams and today it was time for him to visit his new hill!  However, this was not our original plan as we had hoped to visit Moel y Dyniewyd (SH 612 477) and its accompanying hills, but the weather for such a walk was not encouraging with low gloom and drizzled rain, and although the forecast gave for a brighter afternoon, we didn’t fancy the thought of heading up this hill in unfavourable conditions, getting wet in the process, with the prospect of wandering around in wild surrounds trying to pinpoint summit and bwlch positions.  Therefore, we needed a plan B and Aled quickly came up with one; visit a number of lower heighted P30s that neither of us had been to, including the relatively recent new P30 of Bryn y Gwynt. 

This hill was originally listed as Coed Hafod y Llyn in the Welsh P30 lists published on Geoff Crowder’s v-g.me website.  Its name was changed to Bryn y Gwynt due to local knowledge from Aled, with this name also appearing on the series of Ordnance Survey Six-Inch maps.  As well as reclassifying this hill to P30 status, the original LIDAR analysis also promoted Bryn y Gwynt to Dominant status. 

Extract from the Ordnance Survey series of Six-Inch maps

Our quickly re-arranged plan was perfect as a wooded hill would give us shelter from the drizzled rain that still fell as we got our boots on, having parked just off the A4085 road on a track that runs parallel with the train line. 

As we set off the hill loomed above us, with its whole upper section covered in deciduous trees, which on many an occasion can be a delight to walk through.  However, on other occasions deciduous woods can be hellish with no semblance of a path, with going tough through all manner of undergrowth with brambles being the main obstacle.  This hill had a bit of both, but in the main it was a lovely place to walk in. 

Aled leading the way up Bryn y Gwynt

Aled navigated us upward over rich greened rising slopes through mature woodland with plenty of space between trees and occasional rocks interspersed amongst the greenery.  It was a wonderful place to be on such a morning, but with the added bonus of autumnal colour that in a few weeks will adorn this hill, it must be a sheer delight to then visit. 

Without the aid of ten figure grid references for this and the next two summits we visited, each walk was dependent upon finding our own way to the high point, which for me today required contentedly following Aled, who made good steady progress up the hill.  However, this was still an unusual experience for me, as for each walk and survey I usually come prepared with a mass of noted detail, including summit feature and all necessary ten figure grid references for both summit and adjoining bwlch. 

We reached a point that looked to be the summit; I took a few photographs and started to assess the rock that Aled was now standing on for Trimble placement.  Before setting the equipment up we decided to continue in to the wood as ground farther on looked as if it was higher, and so it proved and significantly so. 

The second point we reached was definitely the summit and soon the Trimble was set up atop my rucksack, with the measurement offset noted between its internal antenna and the ground at its base and it was soon quietly beeping away collecting individual datum points. 

Gathering data at the summit of Bryn y Gwynt

Once allotted data were gathered and stored, I closed the equipment down, took a few photographs and packed it away.  We now reversed our inward route avoiding all steep drops and soon found ourselves back on the track with Aled’s car about 100 metres away.  One wooded hill visited and two more to go. 

 

Survey Result: 

 

Bryn y Gwynt (significant name change)

Summit Height:  59.9m (converted to OSGM15, Trimble GeoXH 6000) (significant height revision)

Summit Grid Reference:  SH 59949 44919 (summit relocation confirmed)

Bwlch Height:  28.0m (LIDAR)

Bwlch Grid Reference:  SH 60224 45248 & SH 60226 45258 & SH 60227 45259 (LIDAR)

Drop:  31.9m (30-99m Twmpau addition) (30-99m Sub-Twmpau reclassified to 30-99m Twmpau)

Dominance:  53.21% (Dominant addition)

 

 

For further details please consult the Trimble Survey Spreadsheet