Mapping Mountains – Trimble Surveys – Cilfaesty

 

14.07.21  Pen y Gelli (SO 180 909)

Pen y Gelli (SO 180 909)

With increasingly settled weather I planned a day visiting seven hills, with six being P30s and the other a sub.  I had visited my last hill of the day; Trehafren Hill (SO 100 910) once before, otherwise the remaining six hills were new for me. 

The settled weather also meant warming conditions and as all seven of these hills were positioned above Kerry and Newtown and therefore relatively near to where I live, I could set off early in the morning and head back home before the heat of the day struck. 

I was parked at the start of an overgrown track and walking up a narrow country lane 2 miles to the east of Kerry by 6.30am.  Except for the occasional barking of a disturbed slumbering dog all was peaceful and quiet. 

Prior to visiting these hills I had analysed each with available LIDAR.  Building up contours for both summit and bwlch, all necessary information was written down, with the ten figure grid references produced by LIDAR leading me toward the high point of each hill with the aid of using the Trimble as a hand-held GPS unit. 

LIDAR image of Pen y Gelli (SO 180 909)

A short distance up the narrow lane brought me to a seldom used gate where I trampled down copious amounts of brambles before accessing the field beyond.  This was the field where the summit was situated and the early morning sun was striking the upper part of the hill with long shadows cast from trees and hedgerows adding a dramatic element to the light. 

Even without the aid of LIDAR the summit of this hill would not be difficult to pinpoint and soon the Trimble was set up gathering data.  During data collection I stood downhill of the equipment scribbling all necessary information in my surveying notebook and listened to the occasional sound of a passing car on the A489 road just below and to the south of the hill.  Nothing else seemed to stir, it was peaceful and a good hill to start the day’s surveying and bagging on. 

Gathering data at the summit of Pen y Gelli

To the south across the intervening valley stood Bryn Pant y Drain (SO 178 885), this would be my second hill of the day, and beyond its summit early morning clag hung to higher ground.  I hoped by the time I progressed beyond this hill any lingering low cloud would be burnt off the hills. 

The Trimble GeoXH 6000 set-up position at the summit of Pen y Gelli

Once the allotted data were gathered and stored, I closed the equipment down, packed it away and wandered down the field through the dew soaked grass back to the gate and then the narrow lane.  It was 6.50am when I arrived back at my car, it had only taken 20 minutes to visit and survey the hill, all was quiet and even the disturbed dog that barked upon my arrival had decided to go back to sleep.

 

Survey Result: 

 

Pen y Gelli

Summit Height:  208.5m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SO 18007 90939 (Trimble GeoXH 6000)  

Bwlch Height:  175.4m (LIDAR)

Bwlch Grid Reference:  SO 16961 91121 (LIDAR)

Drop:  33.1m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Dominance:  15.88% (Trimble GeoXH 6000 summit and LIDAR bwlch)

 

 

For further details please consult the Trimble Survey Spreadsheet