Mapping Mountains – Summit Relocations – Y Pedwarau - The 400m Hills of Wales

Moel Eglwys (SH 905 479)  

There has been a Summit Relocation to a hill that is listed in the Y Pedwarau – The 400m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from a Trimble GeoXH 6000 summit survey conducted by Myrddyn Phillips and Aled Williams and LIDAR bwlch analysis conducted by Myrddyn Phillips. 

The summit of Moel Eglwys (SH 905 479)

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

Y Pedwarau – The 400m Hills of Wales.  Welsh hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list are five categories of sub hills; 500m Sub-Pedwarau, 500m Double Sub-Pedwarau, 400m Sub-Pedwarau, 390m Sub-Pedwarau and the 390m Double Sub-Pedwarau.  The list is co-authored by Myrddyn Phillips and Aled Williams and is published on Mapping Mountains in Google Doc format.

Y Pedwarau - The 400m Hills of Wales by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Moel Eglwys, and it is adjoined to the Carnedd y Filiast group of hills, which are situated in the central part of North Wales (Region C1, Sub-Region C1A), and it is positioned encircled by minor roads, with the A5 road to its north, and has the village of Cerrigydrudion towards the east north-east.

When the 1^st edition of the Y Pedwarau was published by Europeaklist in May 2013, this hill was listed with an estimated c 36m of drop, based on the 448m summit spot height positioned at SH 90549 47807 that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and an estimated c 412m bwlch height, based on interpolation of 10m contouring between 410m - 420m.

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

However, it was not until the survey with the Trimble GeoXH 6000 that the summit details for this hill could be accurately re-assessed.

The Trimble survey gives the highest ground on this hill as 447.6m positioned at SH 90580 47962, as opposed to the Trimble giving 447.4m positioned at SH 90552 47811, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the high point of the hill is found to be positioned; in a different field, to a different feature such as in a conifer plantation,  within a different map contour either on Ordnance Survey maps or interactive mapping, to a different point where a number of potential summit positions are within close proximity, 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 or covered reservoir that is considered a relatively recent man-made construct, or the de-twinning of a summit, 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 set-up position at the summit of Moel Eglwys (SH 905 479)

Gathering data at the old summit position of Moel Eglwys (SH 905 478)

Therefore, the height produced by the Trimble GeoXH 6000 survey to the summit of this hill is 447.6m and is positioned at SH 90580 47962.  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 150 metres northward from the position of the map spot height and the previously listed summit position.

The full details for the hill are:

Group:  Carnedd y Filiast

Name:  Moel Eglwys

OS 1:50,000 map:  116

Summit Height:  447.6m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference (New Position):  SH 90580 47962 (Trimble GeoXH 6000)

Bwlch Height:  410.9m (LIDAR)

Bwlch Grid Reference:  SH 90043 48234 (LIDAR) 

 

Drop:  36.6m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Myrddyn Phillips and Aled Williams (September 2014)

Mapping Mountains – Trimble Surveys – Carnedd y Filiast

27.09.14  Moel Eglwys (SH 905 479)  

Garn Prys (SH 887 483)

The northern Arenig is dominated by the moorland mass of Carnedd y Filiast and the isolated peak of Foel Goch with its lower satellite hills surrounding it.  The former has lands descending northward to the A5 road as it bisects the Arenig from the next great upland of Mynydd Hiraethog.  As the land heads toward this road it takes in a number of summits including the cairned top of Garn Prys before it continues to the hill ranges last northern outlier; Moel Eglwys.

I’d only visited Moel Eglwys once before on the 24^th November 2003, it was then the second of four bagging walks of the day and was a quick 16 minute scamper up and down the hill.

Today’s visit was with Aled, we’d already visited Moel y Gydros (SH 914 453) and as the weather was improving the temptation to take in one or two more hills and surveys was too great to resist.

We parked at SH 909 476 where one car can be squeezed onto the grass verge beside the narrow lane.  From here a public footpath heads west around the southern flank of the hill before it swings north-westward toward the area of this hill’s critical bwlch.

As we set off a family were walking down the road toward us, we had passed their parked car a mile or so further down the road.  They were out taking in a small walk around the hill using the track we were about to walk up.  We chatted for a few minutes before our ascent route headed straight up the hill and their planned route continued around the hill.

As we approached the upper part of the hill the views started to open up with Bwlch Blaen-y-cwm standing out seemingly struggling against its adjacent hillsides, forever higher and dominating.

Looking out toward Bwlch Blaen-y-cwm

The Ordnance Survey map has a 448m spot height adjoined to this hill’s summit, this appears on the ground in a high field, adjacent is a fence, the Trimble was placed on this high point and gathered five minutes of data.

Gathering data at the point where the 448m spot height appears on the map

Beyond the fence is another high point, we looked out toward this and both of us thought it higher when compared to the land where the OS spot height indicates is the summit.  This other land is part of a turnip field.  The Trimble has never surveyed in a turnip field before, ever on for new experiences it definitely needed investigating.

Aled in search of the highest turnip

As the last minute of data were logged Aled went turnip investigating, I soon joined him, we marched around a bit, careful not to damage any of the crop.  Once the highest turnip had been found the Trimble was placed on its improvised tripod and gathered the allotted five minutes of data.

The Trimble on its improvised tripod at the high point of the turnip field

This high point was on scrub land just free of turnips, after data were collected we set off, reversing our inward route back to the car.  Moel Eglwys is a fine hill with excellent views, we’ll have to wait and see if its high point is in a turnip field.

Survey Result:

Moel Eglwys

Summit Height:  447.6m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SH 90580 47962 (Trimble GeoXH 6000) (summit relocation)

Bwlch Height:  410.9m (LIDAR)

Bwlch Grid Reference:  SH 90043 48234 (LIDAR)

Drop:  36.6m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Dominance:  8.19% (Trimble GeoXH 6000 summit and LIDAR bwlch)

For further details please consult the Trimble Survey Spteadsheet