Mapping Mountains – Trimble Surveys – Cefn yr Ystrad

06.06.23  Twyn y Waun (SO 084 073) 

LIDAR image of Twyn y Waun (SO 084 073)

Due to the nature of Twyn y Waun the hill received a new category of classification in January 2018; the newly created title was one of Dual Summit Pedwar.  The reason for doing this is that the natural summit of this hill is intact, however it is so inconspicuous compared to what now towers over it that on my previous visit I walked over it twice without realising it was the actual natural summit.

What now towers over the natural summit is the end product of mining waste spoil, which in this area has created three new man-made Pedwar hills and as of June 2023 a newly discovered 400m Sub-Pedwar.  The three Pedwar hills are huge and from a distance look almost natural.  When Aled and I created the category of Dual Summit Pedwar for Twyn y Waun it was with intention to recognise an ascent of the natural and/or adjacent man-made summit as counting toward a completion of the Y Pedwarau.  Today’s objective was to visit the natural summit as the others are obstructed by copious amounts of barb wired fences and time was also now against us as we wanted a meal on our way back toward Welshpool.

The natural summit of Twyn y Waun can easily be visited from an open gate beside a cattle grid, close to the high point of the minor road that skirts this and the other man-made hills to their east.

We parked in a lay-bi and sauntered back down the road to the gate giving access to the open hillside, which hereabouts is a grazing field used by the customary sheep, but also inhabited by many mountain ponies which were here on my last visit and which today were there in great numbers, with their young looking ever so cute in the evening light as the sun cast beautiful colour on the scene. 

Heading down the road toward the gate giving access on to the open hill

I followed Mark through the open gate and up toward the ponies who were all gathered around the summit of the hill.  Once on top I used the Trimble as a hand-held unit to zero in to the ten figure grid reference attained from LIDAR analysis for the high point of the hill. 

The mountain ponies of Twyn y Waun

As the equipment quietly beeped away collecting its individual datum points Mark walked toward the point of the ten figure grid reference given on the Hill Bagging website for the summit.  Visually I found these two positions hard to separate, although Mark thought the LIDAR position a little higher. 

Gathering data at the natural summit of Twyn y Waun

Once I had packed the equipment away I joined Mark and we slowly walked down the hill toward the connecting bwlch of the two Twyn y Waun man-made hills (SO 082 070 and SO 085 065).  Again, the area of the bwlch was heavily guarded by barbed wire, turning our back to the hills for another day we headed to the open gate and the minor road leading back to the awaiting car. 

Heading down from the natural summit of Twyn y Waun

It had been a fine day on the hill with five new Pedwar hills visited for Mark, and three for me with a fourth being a repeat.  All that remained was the drive to the Wheelright Arms in Erwyd for a good bit of pub grub! 

 

Survey Result:

 

Twyn y Waun (reclassified to Dual Summit status)          

Summit Height:  450.6m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SO 08442 07378 (Trimble GeoXH 6000)

Bwlch Height:  380.0m (LIDAR)

Bwlch Grid Reference:  SO 08277 08338 (LIDAR)

Drop:  70.7m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Dominance:  15.68% (Trimble GeoXH 6000 summit and LIDAR bwlch)

 

 

For details on the 1^st visit to Twyn y Waun

For further details please consult the Trimble Survey Spreadsheet