Mapping Mountains – Trimble Surveys – Moel y Gamelin

19.01.14  Moel Morfudd (SJ 159 457), Pt. 497.7m (SJ 161 461), Moel y Gaer (SJ 166 463), Moel y Gamelin (SJ 176 465) and Moel y Faen (SJ 184 475)

Moel Morfudd (SJ 159 457)

With the weather set fair I met Aled at Bwlch Oernant (the Horseshoe Pass) above Llangollen where we parked one car and drove to the start of our walk at Bwlch y Groes (SJ 149 451).  The ridge that leads from this relatively high and narrow road heads north-eastward taking in the summits of four Deweys.  It was our plan to survey all of these and one or two other hills if time permitted.

The crest of the connecting ridge between all of these summits has a wide gravel track meandering across its spine, this somewhat spoils the aesthetic beauty but as all hills are immersed in copious amounts of heather it makes passage soooo much easier!

As we gained height the view below opened up with overnight winter cold having formed mist patches that crept around the lower hill sides as light cast radiant colour on the land.

Early morning mist in the Vale of Llangollen.

Our first summit was Moel Morfudd which has a trig pillar and a small rocky tor on its west side.  The Trimble was set up aligned to the highest part of this small tor and gathered ten minutes of data.

The high point of Moel Morfudd is above the base of the summit trig pillar.

We then surveyed a 497m map heighted hill for Sub-Pedwar status before continuing toward Moel y Gaer with its ancient hill fort on fine display when approaching from the south-west.  The sides of this hill are scarred with wide eroded tracks used by trail riders, somewhat of an infringement in such a beautiful place.

A hillside despoiled - Moel y Gaer.

By now we could see a cloud bank out to the west with darkened patches implying showery weather.  Thankfully the morning’s sunshine only disappeared for an hour or so as this cloud threatened to push eastward.  The sun prevailed and gave us blue skies for the remainder of the walk over the highest hill of the day; Moel y Gamelin which as well as being a Dewey is also a Marilyn.

At least waiting for things such as surveying equipment to do its stuff gives time to look and watch the play of light, and today down in the valley the sun cast its magic on fields of green with the limestone rocks of Mynydd Rhiwabon being highlighted against a dark foreground and milky blue sky.

Play of light on fields of green.

The limestone rocks of Mynydd Rhiwabon.

After five minute’s data collection to the top of a small embedded rock beside the summit cairn we were away heading toward our final objective; Moel y Faen.  During the walk we surveyed every bwlch we came to with good discussion on the placement of the Trimble and the margin of uncertainty associated with where we put it, when compared to where the critical bwlch may actually be.  I decided the whole process was a guess and smiled at what the G&J reaction may be if ever they read this sentence.

The Trimble GeoXH 6000 on the highest point we could find on Moel y Gamelin.

During the whole day the Trimble was in sluggish mood and decided to take its time achieving its required 0.1m accuracy, so much so that it added an approximate 90 minutes to the walks estimated time, and as it was now perched on grass beside a fence at the bwlch of Moel y Faen and seemingly very happy to still be in sluggish mode it meant that daylight was soon to be transformed to dusk and as the sun disappeared behind an adjacent hillside the temperature plummeted.  

Even though the distance of the walk was not great, taking on 11 survey points with a sluggish Trimble can mean a long day on the hill where surveying stamina is called for.  I’m now quite used to this unusual pursuit having practiced near hyperthermic conditions with the G&J team when marooned on a summit in horrid weather for two hours and more, but this novel experience was relatively new for Aled, he came through with flying colours, although if not for the varied topics of discussion I think our patience with our predicament could well have been tested! 

On our last summit of the day; Moel y Faen, we sat and looked out to the north onto agricultural land and far away hills full of heather and as yet unplanned days out with the Trimble.  Below us was Bwlch Oernant and Aled’s awaiting white van, by the time we packed the Trimble away and headed down we’d been out on the hill for over seven hours, with probably the same amount of time waiting for the Trimble as walking on the hill.  It’s funny the enjoyment one gains from the quirky aspects of life.

The summit of Moel y Faen.

It proved an excellent day on the hill even if our esteemed Europeaklist editor could not make the walk, and it was great to see Aled again and have the opportunity to discuss future plans.


Survey Result:

Moel Morfudd

Summit Height:  549.6m (converted to OSGM15)

Summit Grid Reference:  SJ 15965 45762

Bwlch Height:  434.7m (converted to OSGM15)

Bwlch Grid Reference:  SJ 17063 46541

Drop:  114.9m

Dominance:  20.90%

Pt. 497.7m

Summit Height:  497.7m (converted to OSGM15)

Summit Grid Reference:  SJ 16163 46144

Bwlch Height:  478.5m (converted to OSGM15)

Bwlch Grid Reference:  SJ 16080 46096

Drop:  19.2m

Dominance:  3.86%

Moel y Gaer

Summit Height:  503.5m (converted to OSGM15)

Summit Grid Reference:  SJ 16681 46360

Bwlch Height:  465.8m (converted to OSGM15)

Bwlch Grid Reference:  SJ 16515 46252

Drop:  37.7m

Dominance:  7.48%

Moel y Gamelin

Summit Height:  576.9m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SJ 17634 46515 (Trimble GeoXH 6000)

Bwlch Height: c 192m (interpolation)

Bwlch Grid Reference:  SJ 06920 47561 (interpolation)

Drop:  c 385m (Trimble GeoXH 6000 summit and interpolated bwlch)

Dominance:  66.72% (Trimble GeoXH 6000 summit and interpolated bwlch)

Moel y Faen

Summit Height:  547.1m (converted to OSGM15)

Summit Grid Reference:  SJ 18490 47530

Bwlch Height:  488.4m (converted to OSGM15)

Bwlch Grid Reference:  SJ 18034 47277

Drop:  58.7m

Dominance:  10.74%

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