Monday 16 November 2015

Mapping Mountains – Trimble Surveys – Moel y Gamelin


20.10.15  Wynnstay Park (SJ 310 429) and Pentre Clawdd Gorse (SJ 311 442), only bwlch surveyed   

The grounds of Wynnstay Park

The Wynnstay Estate was the family seat of the Wynns, a family whose land owning prowess included much of the southern part of north Wales.  The main house on this old estate has now been converted to flats and private houses.  The high point of Wynnstay Park is a potential P30 with a summit spot height of 141m and a bwlch spot height that is not centred on the valley to valley traverse of 113m, with another summit ; Pentre Clawdd Gorse (SJ 311 442) being potentially higher.

I parked beside the entrance to the estate grounds at SJ 311 433 next to Broth Lodge, leaves crisped under my feet and an occasional car passed me as I quickly marched to the top of the paved road leading to the old estate house.  The 141m map spot height appears on the north-eastern side of an intersection, visually the land to the south-west of this intersection looked higher.

As I continued toward where I thought the highest ground to be situated I watched a photographer frame a shot of autumnal trees above their fallen leaves, I stopped and we chatted, I looked through the viewfinder of his camera and the composition looked stunning, my photo taken from the same position looks drab in comparison.  I explained what I hoped to do and asked him where he thought the highest ground to be positioned, he looked around and pointed toward the place where I had independently also judged the summit of Wynnstay Park to be situated.

I placed the Trimble on top of my rucksack and the long waiting game began.  After about ten minutes the Trimble’s accuracy level was struggling to make 0.35m, so I switched it off and created a new file and set it up facing in a different direction but still aligned over the high point.  I then stood back and waited………. and waited……….. and waited.

During this time I took a number of photos of trees and a ‘Caution Squirrels Crossing’ sign.  It took an age for the Trimble to achieve its required 0.1m accuracy level before data should be logged, but once it had I quickly pressed ‘Log’ and waited for the five minutes of data collection to be complete.

This sign amused me during my long wait for the Trimble to achieve its 0.1m accuracy level before data should be logged

The Trimble set-up position at Wynnstay Park

By now the sun was low on the horizon and once the Trimble was packed away I scampered off down the road, past my car and on to a footpath that led over a field toward the first of two bwlch surveys I wanted to complete.  This first potential bwlch position was in a grassed field with an enclosed footpath next to it and allotments in front of it.  As the Trimble gathered data I chatted with a couple of people who were out walking their dogs, one kindly pointed me in the right direction for easiest access toward the footpath near to where I wanted to gather the second potential bwlch data set.

Gathering data at the first of two set up positions for the bwlch

This second position was in another grassed field with a graveled track adjacent to it and separated from it by a large hedge.  As the Trimble gathered its 14th and last data set of the day I stood uphill of it and peered down on the field and looked at the land as it continued its downward progress from where the Trimble was quietly beeping away.

Gathering data at the second of two set up positions for the bwlch

Once the Trimble was packed away I followed the footpath from the graveled track uphill to the field and my inward route back to my car.  It had been another good day visiting hills made out of mine spoil and ones luxuriating themselves in country parks.

The paved road leading toward the summit of Wynnstay Park 

Survey Result:


Wynnstay Park

Summit Height:  141.2m (LIDAR, and confirmed as lower than Pentre Clawdd Gorse [SJ 31131 44252])

Summit Grid Reference:  SJ 31001 42958 (LIDAR) (summit relocation)

Bwlch Height:  128.2m (LIDAR)

Bwlch Grid Reference:  SJ 31418 43293 (LIDAR)

Drop:  13.0m (LIDAR)

Dominance:  9.22% (LIDAR)





Pentre Clawdd Gorse

Summit Height:  142.0m (converted to OSGM15, from subsequent Trimble GeoXH 6000 survey and confirmed as higher than Wynnstay Park [SJ 31001 42958])

Summit Grid Reference:  SJ 31131 44252 (from subsequent Trimble GeoXH 6000 survey) (summit relocation confirmed)

Bwlch Height:  109.8m (LIDAR)

Bwlch Grid Reference:  SJ 30789 44141 (LIDAR)

Drop:  32.2m (Trimble GeoXH 6000 summit and LIDAR bwlch) (100m Twmpau addition)

Dominance:  22.67% (Trimble GeoXH 6000 summit and LIDAR bwlch)
  




For the post detailing the summit survey of Pentre Clawdd Gorse

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




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