Friday, 7 August 2015

Mapping Mountains – Significant Height Revisions – Y Trichant

Old Radnor Hill (SO 251 587)

There has been a Significant Height Revision initiated by a survey with the Trimble GeoXH 6000 to the listing of the Y Trichant, with the following details being retrospective as the survey that resulted in this height revision was conducted on 11th January 2014.

The name of the hill is Old Radnor Hill and it is situated in the southern part of the Fforest Glud range of hills, which is known in English as the Radnor Forest, this range of hills is in the heartland of mid Wales and the survey was conducted on a fine and bright winter’s day.

The hill is listed in the Y Trichant, these are the hills in the 300m height band of the Twmpau  (thirty welsh metre prominences and upward) and it is situated south-east of Maesyfed (New Radnor), with the nearest major road being the A44 which skirts the hill on its northern and eastern side.  The A44 road to the east of this hill comprises a road cutting which would significantly increase this hill’s drop value if the natural bwlch is considered to no longer exist and if the nearest point to it is not taken as that for the drop value of the hill, with an on-site visit judging the remains of the natural bwlch to be situated inside what is now an old Chapel.

The summit height of Old Radnor Hill has been dramatically decreased over time due to it being quarried.  However, prior to the survey with the Trimble GeoXH 6000 its listed height was an estimated c 317m based on the uppermost contour on the Ordnance Survey enlarged mapping hosted on the Geograph website showing part of a 315m contour ring.

This hill's new summit height is 312.6m, which is 4.6m lower than its previously estimated listed height and 2.4m lower than the 315m uppermost ring contour on the Ordnance Survey enlarged mapping on the Geograph website.

The full details for the hill are:

Cardinal Hill:  Gwaun Ceste

Summit Height (New Height):  312.6m (converted to OSGM15)

Name:  Old Radnor Hill

OS 1:50,000 map:  148

Summit Grid Reference:  SO 25135 58770
Drop:  97.1m (converted to OSGM15)

The quarried remains of Old Radnor Hill

Myrddyn Phillips (August 2015)

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