Thursday 22 February 2018

Mapping Mountains – Summit Relocations – Y Trichant and Y Trechol – The Dominant Hills of Wales


Upper Park (SJ 189 052)

There has been confirmation of a Summit Relocation to a hill that is listed in the Y Trichant and Y Trechol – The Dominant Hills of Wales, and which was initiated by a survey with the Trimble GeoXH 6000, with the survey that confirmed this summit relocation taking place on the 7th January 2018.

The criteria for the two listings that this summit relocation affects are:

Y Trichant - Welsh hills at and above 300m and below 400m in height that have 30m minimum drop. 

Y Trechol - The Dominant Hills of Wales - These are the Welsh P30 hills whose prominence  equal or exceed half that of their absolute height.  With the criteria for 
Lesser Dominant status being those addition Welsh P30 hills whose prominence is 33% or more and below 50% of their absolute height.

The name of the hill is Upper Park and it is situated in the Carnedd Wen range of hills which are in the south-eastern part of North Wales (Region A, Sub-Region A4), and it is positioned between the A 458 road to its north and the A 483 road to its south-east, and has the town of Y Trallwng (Welshpool) to its north-east.

Upper Park (SJ 189 052)

As the summit of the hill is not on designated open access land and a part of a private estate permission to visit should be sought, for those wishing to do so there are a number of options for an ascent, all of which use tracks through forested plantations.

When this hill was originally listed in the Welsh P30 lists on Geoff Crowder’s v-g.me website the summit position was given as SJ 189 052, and although this six figure grid reference matches that of the position of the confirmed relocation, its position was to the 352m spot height that appears on the Ordnance Survey 1:25,000 Explorer map (SJ 18895 05292).

Two data sets were taken with the Trimble GeoXH 6000, the first at the high point of the hill which is in a deciduous plantation known as Crown Wood.  The second was taken to the high point of the adjacent field where the 352m spot height appears, these results are given below:

1st survey, inside Crown Wood at high point of hill:  354.0m (converted to OSGM15)

2nd survey, adjacent field where the 352m spot height appears:  352.4m (converted to OSGM15)

Extract from the Ordnance Survey Interactive Coverage Map hosted on the Geograph website showing the summit position in relation to the spot height position

Therefore, the confirmation of the position of the relocated summit is at SJ 18980 05270 and this is ground within a deciduous wood, this position is approximately 100 metres east south-eastward from where the 352m spot height appears on the Ordnance Survey 1:25,000 Explorer map.


The full details for the hill are:

Group:  Carnedd Wen

Summit Height:  354.0m (converted to OSGM15)

Name:  Upper Park

OS 1:50,000 map:  125

Summit Grid Reference (New Position):  SJ 18980 05270 
        
Drop:  177.0m (converted to OSGM15)

Dominance:  49.998%


The Trimble GeoXH 6000 gathering data at the summit of Upper Park with the position of where the 352m spot height appears on the ground in the frosted field in the centre background of this photo


Myrddyn Phillips (February 2018)











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