Mapping Mountains – Trimble Surveys – Mynydd Twr

28.10.18  Pen y Foel (SH 425 844)  

Pen y Foel (SH 425 844)

Pen y Foel was my fourth P30 of the morning and if time and surveying inclination permitted I hoped to visit another four P30s during the remainder of the day.  The hill is positioned overlooking the small community of Llannerch-y-medd on Ynys Môn and is crowned by the remains of the Llwydiarth Tower; which is a squat red bricked structure.

A public footpath heads northward from the periphery of Llannerch-y-medd and confidently strikes out toward the summit of the hill.  Today the edges of the green track which constitutes the footpath were slightly overgrown, but not so much as to lessen my pace or dampen my enthusiasm for another new hill.

The way to the hill

The green track soon led to an open grazing field where the remains of one forlorn looking house stands, with the Llwydiarth Tower situated just beyond perched on the summit of the hill, and which soon came in to view as I gained height.

The Llwydiarth Tower at the summit of Pen y Foel

Arriving at the summit I quickly judged where the high point of the hill was situated and soon had the Trimble in position and as the equipment was now placed beside the brick structure I decided that a ten minute data set should be taken.

The Trimble set-up position at the summit of Pen y Foel

Once the Trimble was activated to gather data I stood away from it and looked out across the island and beyond the Menai Strait to the elongated spine of Wales’ highest mountains on the mainland of this wonderful and beautiful country where I just happen to live.

Gathering data at the summit of Pen y Foel

Once data were gathered and stored I packed the Trimble away and followed my inward route back to my car.  I now wanted to head further north and visit four more hills over two walks and take data from the summit of the 178m map heighted Yr Arwydd (SH 472 854) and the 177m map heighted Mynydd Eilian (SH 472 917), with the former the recognised high point of Ynys Môn (outside of Mynydd Twr on Ynys Gybi) and the listed Marilyn.

Survey Result:

Pen y Foel 

Summit Height:  122.5m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SH 42575 84415 (Trimble GeoXH 6000)

Bwlch Height: c 61m (interpolation)

Bwlch Grid Reference:  SH 44053 82788 (interpolation)

Drop:  c 62m (Trimble GeoXH 6000 summit and interpolated bwlch)

Dominance:  50.21% (Trimble GeoXH 6000 summit and interpolated bwlch) (Lesser Dominant reclassified to Dominant)

For further details please consult the Trimble Survey Spreadsheet