Saturday, 23 July 2016

Mapping Mountains – Summit Relocations – Y Pedwarau

Moel y Ci (SH 590 657)

This is the twenty seventh post under the heading of Summit Relocations, with the survey that resulted in the following details taking place on 14th July 2016 in good, clear and bright conditions.

The twenty seventh major summit relocation initiated from a survey with the Trimble GeoXH 6000 was conducted in the hills of the Glyderau, with the small community of Rhiwlas situated to the hill’s west, and which is positioned between Caernarfon to its west south-west and Bangor to its north.

The hill is listed as a Pedwar (Y Pedwarau [Europeaklist May 2013]), these are the Welsh 400m hills with 30m minimum drop, with its summit position given as SH 593 659 which is the position of the 410m spot height that appears on current Ordnance Survey 1:50,000 maps.  However, the summit area of this hill is given four small uppermost 410m ring contours on Ordnance Survey 1:25,000 maps.  The grid reference for each position was noted and the intention was to survey each in turn to ascertain the high point of the hill, however sometimes contours do not match what appears on the ground and therefore the ground where one ring contour appears was visually judged lower and was not surveyed, whilst another point not given a 410m ring contour on Ordnance Survey maps was judged to warrant a survey.  The results of the four surveys appear below:

1st survey:  409.9m (409.864m, converted to OSGM15) at SH 59083 65767

2nd survey:  409.5m (409.527m, converted to OSGM15)) at SH 59086 65786

3rd survey:  409.4m (409.415m, converted to OSGM15) at SH 59104 65898

4th survey:  409.5m (409.486m, converted to OSGM15) at SH 59375 65941

The position of the fourth 410m ring contour that was not surveyed is at SH 59167 65790

Access to the hill is relatively easy as a narrow lane heads eastward from the village of Rhiwlas and meets open access land and continues as a green track which crests the bwlch between Moel y Ci and Parc Drysgol.  A path continues from the top of the green track through the heathery southern slopes of the hill and goes to the summit.

The position of the relocated summit is at SH 59083 65767 and is the top of a flattish rock amongst heather, this position is given a small 410m ring contour on the Ordnance Survey 1:25,000 Explorer map.

The full details for the hill are:

Cardinal Hill:  Glyder Fawr

Summit Height:  409.9m (converted to OSGM15)

Name:  Moel y Ci

OS 1:50,000 map:  114, 115

Summit Grid Reference (New Position):  SH 59083 65767 
Drop:  c 72m

The Trimble GeoXH 6000 gathering data at the summit of Moel y Ci, with the old position of the summit in the background on the left of this photograph

Myrddyn Phillips and Aled Williams (July 2016)

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