Mapping Mountains – Summit Relocations – 200m Twmpau

 

Stingwern Wood (SJ 145 000) 

There has been a Summit Relocation to a hill that is listed in the 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from detail on contemporary maps produced from Ordnance Survey data and a Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

Stingwern Wood (SJ 145 000)

The criteria for the list that this summit relocation applies to are: 

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub category entitled the 200m Sub-Twmpau consisting of all Welsh hills at or above 200m and below 300m in height that have 20m or more and below 30m of drop.  With the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Stingwern Wood, and it is adjoined to the Carnedd Wen group of hills which are situated in the south-eastern part of North Wales (Region A, Sub-Region A4), and it is encircled by minor roads with the B4390 road further to its north, the B4389 road further to its west and the A483 road further to its south-east, and has the village of Aberriw (Berriew) towards the east. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website the qualifying hill was included in the main P30 list with a summit height of 251m positioned at SJ 154 997, which was taken from the spot height that appears on the Ordnance Survey 1:25,000 Explorer map. 

Extract from the Ordnance Survey 1:25,000 Explorer map

After the accompanying sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with an estimated c 60m of drop, based on an estimated c 258m summit height and an estimated c 198m bwlch height, with both values based on interpolation of 10m contouring that appear on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, with the summit also relocated to SJ 145 000. 

The summit of this hill has now been surveyed with the Trimble GeoXH 6000, resulting in 260.0m at SJ 14514 00063 and this height comes within the parameters of the Summit Relocations used within this page heading, these parameters are: 

The term Summit Relocations applies when the hill’s high point is found to be positioned; in a different field, to a different feature such as in a conifer plantation, placed within a different map contour, to a different point where a number of potential summit positions are within close proximity, or when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary that is judged to be a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist. 

The Trimble GeoXH 6000 gathering data at the summit of Stingwern Wood

Therefore, the new listed summit height for this hill is 260.0m and is positioned at SJ 14514 00063, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and is approximately 1km west north-westward from where the originally listed summit is positioned. 

 

ills of Wales, and are reproduced below@

The full details for the hill are:

Group:  Carnedd Wen

Name:  Stingwern Wood

OS 1:50,000 map:  136

Summit Height:  260.0m (converted to OSGM15, Trimble GeoXH 6000) 

Summit Grid Reference (New Position):  SJ 14514 00063 (Trimble GeoXH 6000) 

Bwlch Height:  c 198m (interpolation) 

Bwlch Grid Reference:  SJ 14414 00402 (interpolation) 

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

 

Myrddyn Phillips (March 2021)