Mapping Mountains – Hill Reclassifications – Y Trichant – The 300m Hills of Wales

Gallt y Goedhwch (SJ 137 159) – Sub-Trichant reclassified to Trichant

There has been confirmation of a reclassification to the list of Y Trichant – The 300m 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 survey conducted by Myrddyn Phillips with assistance from Mark Trengove and LIDAR analysis conducted by Myrddyn Phillips. 

Gallt y Goedhwch (SJ 137 159)

The criteria for the list that this reclassification applies to are:

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant, with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017, and the Introduction to the Mapping Mountains publication of the list appearing on the 1^st January 2022. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Gallt y Goedhwch, and it is adjoined to the Foel Cedig group of hills, which are situated in the southern part of North Wales (Region A, Sub-Region A3), and it is positioned encircled by minor roads, with the A490 road farther to its north-east, the B4393 road farther to its north-west, the B4382 road farther to its west and the A495 road farther to its south-east, and has the village of Meifod towards the south-east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included as the non-prioritised summit in the Hills to be surveyed sub list that accompanied the main P30 list with an accompanying note stating; Two points of same height (Maes-y-castell SJ137155).  The hill previously listed as Maes-y-castell has now been renamed as Lower Field, and it was this hill that was listed as the prioritised qualifying P30. 

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

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with 114m of drop, based on the 325m summit spot height and the 211m bwlch spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map.

However, it was not until the survey with the Trimble GeoXH 6000 that the details for the summit of this hill could be accurately re-assessed.  The hill has also now been analysed by LIDAR (Light Detection & Ranging); a technique which produced highly accurate height data that is now freely available for much of England and Wales.

The Trimble GeoXH 6000 gathering data at the summit of Gallt y Goedhwch

 

LIDAR bwlch image of Gallt y Goedhwch

Therefore, the confirmation of the reclassification of this hill from Sub-Trichant status is due to a Trimble GeoXH 6000 summit survey and LIDAR bwlch analysis, resulting in a 325.7m summit height and a 212.1m bwlch height, with these values giving this hill 113.6m of drop, which is sufficient for it to be classified as a Trichant. 

 

The full details for the hill are: 

Group:  Foel Cedig 

Name:  Gallt y Goedhwch 

OS 1:50,000 map:  125

Summit Height:  325.7m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SJ 13709 15922 (Trimble GeoXH 6000)                                     

Bwlch Height:  212.1m (LIDAR) 

Bwlch Grid Reference:  SJ 11170 14801 (LIDAR) 

Drop:  113.6m (Trimble GeoXH 6000 summit and LIDAR bwlch) 

 

Myrddyn Phillips (September 2022)

 

 

 

 

 

 

  

Mapping Mountains – Trimble Surveys – Foel Cedig

21.04.14  Gallt y Goedhwch (SJ 137 159) and Lower Field (SJ 137 155)

Gallt y Goedhwch (SJ 137 159)

Mark suggested meeting up and had originally thought of heading for Rhobell Fawr (SH 786 256), this was quickly shelved as the forecast predicted intense thunderstorms in mid Wales for the afternoon.  The next idea was a circuit in the Howgills, but it seemed the worsening weather was going to hit that part of England as well.  However, the forecast for the morning was set fair so he suggested upping his HuMP total and visiting Gallt y Goedhwch which is situated in the tranquil lands above the Dyffryn Meifod, a few miles from Welshpool.

The hill also had the added advantage of having two similar heighted tops for its main summit which has a 325m spot height on the Ordnance Survey enlarged Geograph map, and just to the south is another summit which has a small uppermost c 320m ring contour.  This has caused a bit of debate in the past between Douglas Law, Chris Watson, George Gradwell and me.  Hopefully the Trimble could distinguish which of the two similar heighted tops is the higher, give a height to the southerly summit, confirm this to be lower than the main summit and if we surveyed the bwlch between we could also give a drop value for the southern summit.  I also hadn’t visited this hill, so it would be a new P30 tick for me.

I had suggested starting from a relatively high road and approaching the hill from the south-east, but Mark pointed out that this route had a reputation for meetings with an inquisitive farmer, so we parked at a road junction where sufficient space for at least one car can be found at SJ 139 169.  This route would also enable us to have a good walk, instead of a quick bag.

As Mark was getting his boots on I sauntered over to the near hedge row and admired the colourful crop of wild flowers, all newly sprung with that luxuriant colour of early spring, highlighted by morning sunshine.  As we started eastward down the lane toward the farm of Gwaelod (SJ 142 164) we soon encountered all manner of friendly animals from donkeys to dogs; all wanted a pat and a lot of fuss.  From this vantage point Gallt y Goedhwch rose steeply above the green fields with its lower slopes covered in deciduous woodland, it was these slopes that we hoped to gain access on through to the summit.

We left the lane before the farm and joined a public footpath across a field which aimed for the lower reaches of the wooded slopes and a track that contoured its way around the hill.  Once in the wood we had to pick our spot when to bear left and head uphill.  Once picked, we wondered if an easier route may have existed further up the track, as our route was unforgivingly steep.  It was all rather beautiful though, as the land was covered in fallen foliage interspersed amongst mature trees, all quiet except for our labours and the welcome addition of bird song.

Crossing the field before entering the wood

The steep slopes in the wood

As height was gained we encountered a high fence, no doubt put in place for pheasant rearing.  A few minutes later and the steep slope started to relent as we came out of the wood to the northerly ridge of the hill.  Such a wonderful place to be on a morning bathed in blue sky, but we knew this was not going to last as the heat of the day was predicted to set off intense thunder showers in the early afternoon.

Emerging out of the wood on to the upper slopes of Gallt y Goedhwch

We were soon on the high point, or the two high points, we assessed the height difference between each and thought the more south-westerly one to be the higher, Mark thought by as much as 0.5m.  The Trimble was placed on each in turn, gathering ten minutes of data from both.  Each high point is easily identifiable as the summit consists of a small rocky ridge with the ground conveniently reaching its respective high points without bothersome intermediate rocky bits vying for possible other high points, outside of the two that we were now surveying and of course the other southerly summit that could be as high!!

The highest part of Gallt y Goedhwch is the south-westerly point of the main summit

Mark enjoys the rest whilst the Trimble gathers data at the north-easterly point of the main summit with the high point of the hill in the background

Once the data was stored we made our way to the bwlch between the main summit and the southerly one and had a good look at the ground, once the position of the critical bwlch was decided upon the Trimble was placed on the spot and gathered five minutes of data.

Gathering data at the bwlch between the two hills

The southerly summit is quite steep when approaching from its northerly bwlch.  The name of Maes y Castell appears on the map near to the summit of this hill but the Ordnance Survey 1:2,500 map from 1975 implies that this name is that of the farm at SJ 137 154, whilst the name of Y Bwythyn appears on the OS enlarged Geograph map, this name seems to be applicable to a cottage, whilst the Tithe map gives the name of Lower Field for land where the summit is situated and therefore it is this latter name that is now being used for that of the hill.  This southerly summit also consists of a small rocky ridge, within a few minutes the Trimble was balanced on top, aligned with its highest point.  Thankfully there was only a slight whisper of breeze that helped negate the heat of the sun, otherwise strong wind would no doubt have dislodged the Trimble and rolled it down the hillside.  Another ten minutes of data was collected as we lounged around in the sun and admired the view.

The Trimble GeoXH 6000 on the summit of  Lower Field

We headed westward from the bwlch and re-joined our inward track in the wood as the blue of the sky was replaced by an ominous murkiness; heralding what we thought was the impending storm.  Thankfully this never materialised for this part of Wales as the predicted intense rain concentrated itself to the south of the country. 

Four data points gathered and hopefully a few questions answered by the results, an excellent small walk taking just over three hours.

An Easter bunny, unfortunately a dead one.  We came across this during our descent back through the wood

Survey Result:

Gallt y Goedhwch

Summit Height:  325.7m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SJ 13709 15922 (Trimble GeoXH 6000)

Bwlch Height:  212.1m (LIDAR)

Bwlch Grid Reference:  SJ 11170 14801 (LIDAR)

Drop:  113.6m (Trimble GeoXH 6000 summit and LIDAR bwlch) (Sub-Trichant reclassified to Trichant)

Dominance:  34.89% (Trimble GeoXH 6000 summit and LIDAR bwlch)

Lower Field (significant name change)

Summit Height:  321.1m (converted to OSGM15)

Summit Grid Reference:  SJ 13704 15586

Bwlch Height:  295.3m (converted to OSGM15)

Bwlch Grid Reference:  SJ 13681 15650

Drop:  25.8m (Trichant reclassified to Sub-Trichant)

Dominance:  8.03%

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