Mapping Mountains – Significant Name Changes – 200m Twmpau

Gallt y Celyn (SH 811 542)

There has been a Significant Name Change to a hill that is listed in the 200m Twmpau, and the following details are in respect of a hill whose summit was surveyed with the Trimble GeoXH 6000 on the 24^th December 2013 and whose bwlch was surveyed on the 23^rd February 2016. 

The hill is situated in the Mynydd Hiraethog group of hills, and is positioned to the north of the Afon Conwy and the A5 road and between the towns of Betws-y-coed to its north-west, Pentrefoelas to its south-east and Llanrwst to its north.

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

The hill appeared in the Sub List that accompanied the 200m P30 list on Geoff Crowder’s v-g.me website and was later added to the P30 list when drop values based on interpolation were included.  It was subsequently reclassified to a 200m Sub-Twmpau based on its summit survey and finally reinstated as a 200m Twmpau after its bwlch was surveyed.

The hill originally appeared in this Sub List under an invented name of Bryn Graeanllyn, with an accompanying note stating; Name from buildings to the West.  As was my liking during my early hill listing I thought it appropriate to invent a name for a hill if no name seemed to appear for it on Ordnance Survey maps of the day.  My preference was to use farm names and put Pen, Bryn or Moel in front of them.  This is not a practice that I now advocate as with research either conducted locally or historically an appropriate name for the hill can usually be found.

Bryn Graeanllyn

258m

SH811542

116

18

Name from buildings to the West

The name this hill is now listed by is Gallt y Celyn and this was derived from the Tithe map.  The term Tithe map is generally given to a map of a Welsh or English parish or township and which was prepared after the 1836 Tithe Commutation Act.  This act allowed tithes to be paid in cash rather than goods.  The Tithe maps gave names of owners and occupiers of land in each parish and importantly for place-name research they also included the name of enclosed land.  This enclosed land is usually based on a field system, however not every field is given a name, but many are and especially so in Wales.

The enclosed land is given the number of 2434 on the Tithe map

The enclosed land where the summit of Gallt y Celyn is situated is given the number of 2434 on the Tithe map, this can be cross referenced against the apportionments; it is these apportionments that give the name of the owner or occupier of the land as well as the name of the land.  The land where the summit of this hill is situated is named as Allotment on Gallt y Celyn and is described as Rocky Pasture; it appears in the county named as Denbigh.

When cross referenced in the apportionments the enclosed land is named as part of Gallt y Celyn

This is an example where the practice of transferring the map name given to a lower heighted hill to that of a near higher hill that is unnamed on current Ordnance Survey maps, and then using a directional name for the lower hill based on the name now given to the higher hill is foolhardy.  The details of this example appear below:


200m Twmpau:

Dinas Mawr    254.0m (converted to OSGM15) summit at SH 808 539

Gallt y Celyn    257.6m (converted to OSGM15) summit at SH 811 542

The hill at SH 808 539 is named Dinas Mawr on Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps, whereas that of Gallt y Celyn is unnamed on Ordnance Survey maps.  By transferring the name of the lower hill to the higher hill and then using a directional name for the lower hill, you get:

Tumps:

Dinas Mawr SW Top at SH 808 539

Dinas Mawr at SH 811 542

Both of these names are now inappropriate for the hill they are given to.  This is how these hills are currently listed in Mark Jackson’s Tumps.  If only the same amount of time were spent on place-name data when compared to the time spent on numerical data the contents within all hill lists would improve dramatically.

The full details for the hill are:

Group:  Mynydd Hiraethog

Name:  Gallt y Celyn

Previously Listed Name:  Bryn Graeanllyn 

Summit Height:  257.6m (converted to OSGM15)

OS 1:50,000 map:  116

Summit Grid Reference:  SH 81121 54259  

Drop:  30.1m (converted to OSGM15)

For details on the summit survey and the bwlch survey of Gallt y Celyn.

Myrddyn Phillips (June 2016)

Mapping Mountains – Hill Reclassifications – 200m Twmpau

Gallt y Celyn (SH 811 542) - 200m Sub-Twmpau reclassified to 200m Twmpau

There has been a reclassification within the 200m Twmpau (thirty welsh metre prominences and upward) hill list instigated by a survey with the Trimble GeoXH 6000.   The hill has a convoluted history of reclassification and is situated just to the north of the A 5 and southward of the small community of Capel Garmon and south-eastward of the town of Betws-y-coed, and is positioned in the Mynydd Hiraethog range of hills.

The Trimble GeoXH 6000 survey that resulted in this hill’s reclassification from a 200m Sub-Twmpau to a 200m Twmpau was conducted in the afternoon of the 23^th February 2016 on a beautiful winter’s day in good, dry and sunny conditions.

The hill is unnamed on current Ordnance Survey maps but is given as a part of Gallt y Celyn on the Tithe map and therefore this name is deemed appropriate to use.

 

Access to the hill is relatively easy as there is a public footpath approaching from the north which can be accessed from Capel Garmon, and also one from the south-east which can be accessed from a steep minor lane that heads north from the A 5.  The summit of the hill is only a short distance from where these footpaths meet and is on open access land.

The hill has a convoluted history of inclusion and exclusion from the 200m P30 Welsh list as it was originally included in the ‘Hills to Survey’ Sub-List that accompanied the main P30 lists on Geoff Crowder’s v-g.me website.  This Sub-List was reliant upon the details on Ordnance Survey maps being correct and did not take in contour interpolation for inclusion within the main P30 list.  After the Sub-List was standardised and contour interpolation used, the hill was reclassified to a P30 with c 30m of drop, based on a 258m summit spot height and an estimated bwlch height of c 238m.  To complicate matters this hill had twin tops, both given a 258m spot height on Ordnance Survey maps, these tops were surveyed with the Trimble on the 24^th December 2013 with the following results:

257.610m (converted to OSGM15) at SH 81121 54259.

257.093m (converted to OSGM15) at SH 81007 54476.

Although the twin tops had been separated the bwlch was not surveyed and as it was estimated to be c 238m high, the drop for this hill was accepted as being just under the qualifying minimum drop of 30m and therefore the hill re-joined the ranks of Subs.

It was always my intention to survey the bwlch and determine once and for all the classification of the hill, and on the 23^rd February I found myself immersed in a water laden bog gathering the allotted five minutes of data.  This survey resulted in a bwlch height of 227.5m (227.529m, converted to OSGM15), which gave this hill 30.1m (30.081m) of drop, and therefore it re-joins the ranks of P30 Twmpau hills.

The full details for the hill are:

Cardinal Hill:  Mwdwl Eithin

Summit Height:  257.6m (converted to OSGM15)

Name:  Gallt y Celyn

OS 1:50,000 map:  116

Summit Grid Reference:  SH 811 542

Drop:  30.1m (converted to OSGM15)

Gallt y Celyn (SH 811 542) in the centre foreground of this photograph and which has now been re-instated as a 200m P30 Twmpau.  Photograph taken from the summit of Dinas Mawr (SH 808 539)

For details on the survey that resulted in this hill being reclassified from a 200m Sub-Twmpau to a 200m Twmpau please click {here} for summit and {here} for the bwlch survey.

Myrddyn Phillips (February 2016)

Mapping Mountains – Trimble Surveys – Mynydd Hiraethog

23.02.16  Gallt y Celyn (SH 811 542, only bwlch surveyed)   

The area of the bwlch of Gallt y Celyn

Just to the north of the busy A 5 as it nears its westward journey toward Betws-y-coed is a tranquil area of small hills, seemingly wildly situated where bracken and small rock outcrops predominate.  Amongst this land are situated occasional farms, with a narrow and steep minor road giving access to an otherwise undisturbed place where hill walkers are a rarity.  I’d visited this area in December 2013 when on my way to Nantlle to spend Christmas.  It was then the 24^th and a chill wind blew hail showers across the land.  On that day I’d surveyed three tops, two of which are given a 258m spot height on Ordnance Survey maps.  The Trimble separated these tops giving one a height of 257.6m (SH 81121 54259) and the other a height of 257.1m (SH 81007 54476).  With an estimated bwlch height of c 228m adjoined to the higher of the two tops it meant that this hill had an estimated drop of just less than 30m.  My aim today was to survey the critical bwlch and determine if the hill had sufficient drop to be classified as a P30 Twmpau.

I parked on a muddy grass verge beside where a track heads north-west bisecting the hills of Dinas Mawr (SH 808 539) and the southerly of the two previously twin tops, which is the higher 257.6m summit by Trimble survey. 

The track was awash in mud, and although I left it almost immediately following where a footpath heads north on the map, the underfoot conditions didn’t improve, as cattle had stomped their way through this land and the ground was churned and boggy.

My route took me toward where the map indicated a Chambered Long Cairn is situated, the ground was muddy and wet and the going was slow, albeit the distance between where I left my car and the position of the bwlch is not great.  I had difficulty following the footpath on the ground and had to clamber over one wall.  As I approached the area of the bwlch reed grass swan away across the land, indicating the whole area to be bog bound.  Crossing this land is a track, which again was very muddy, that connects the farm of Ty’n-y-coed with that of Graeanllyn.

I took two data sets, one from the low point of the track as it crossed a stream which gurgled its way south.  To the immediate north of the track was a swamp of oozing mud which was almost level with it, whilst the stream on the southern edge of the track was 0.91m lower than it.  This indicated that the track had in effect almost damned this part of land, and although the water flowed under the track, it seemed the land to its north had been partly turned in to a quagmire, and after gathering a data set on the track, it was this land I now headed in to.

Gathering data from the low point of the track

Thankfully patches of green heaven were interspersed amongst copious amounts of standing water as I ventured in to the delights of the reed grass.  I chose a spot where I could safely position the Trimble on top of my rucksack without each being sunk and lost in the bog of standing water.

Gathering data at the critical bwlch of Gallt y Celyn

After five minutes of data were collected I switched the Trimble off, packed it away and retraced my steps out of the bog and across the mud splattered land to my car.

The fourth and last place I wanted to visit during the remaining daylight hours was to the south of Wrexham, and so an approximate hour’s drive was ahead of me, and with it now being past 2.00pm I could not linger.  

Survey Result:

Gallt y Celyn (significant name change)

Summit Height:  257.6m (converted to OSGM15, from previous Trimble GeoXH 6000 survey) 

Summit Grid Reference:  SH 81121 54259 (from previous Trimble GeoXH 6000 survey) 

Bwlch Height:  227.5m (converted to OSGM15)

Bwlch Grid Reference:  SH 81548 54426

Drop:  30.1m (200m Sub-Twmpau re-instated as 200m Twmpau)

Dominance:  11.68%

For the post detailing the summit survey of Gallt y Celyn please click {here}

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

Mapping Mountains – Trimble Surveys – Mynydd Hiraethog

24.12.13  Dinas Mawr (SH 808 539), Gallt y Celyn (SH 811 542) and Gallt y Celyn (SH 810 544)

Dinas Mawr (SH 808 539)

One of the advantages of having the Trimble is being able to accurately survey hills such as the ones visited today.  With G&J Surveys prioritising English and Welsh marginal Marilyns and high prominence Sub-Marilyns, English and Welsh Nuttalls and continuing with our visits to Scotland, and with Alan Dawson concentrating on Scottish Marilyns, Sims and the occasional Hump, and with John Fitzgerald roaming around a multitude of Irish hills, it means that many parts of Wales and an occasional visit in to England with the Trimble can produce accurate data on hills that none of the above will visit.  Today was a prime example as I wanted to confirm the status of Dinas Mawr as it was originally listed as a Sub in the Welsh 200m P30 list, and was later promoted to P30 status through contour interpolation, this hill also has an adjacent P30 twin top, so I wanted to de-twin this hill as well.

The three summits are on open access land and are easily approached from a bridleway just above the A5.  The higher hills to the west and south were bathed under winter grey cloud, this heralded the heavy showers that were forecast and as I made my way through a gate toward the bwlch of Dinas Mawr the first of these hit me as a vicious hail shower.

The going under foot was problematical as small trees interspersed with bracken and copious amounts of bramble made for rather slow progress.  I assessed the point of the bwlch from various angles, chose my spot and gathered five minutes of data before heading up through the bracken and rock outcrops toward the summit of Dinas Mawr.

The top is crowned by a few quartz rocks and marks the highest point of a fine hill; I removed the quart cairn and set the Timble up to gather data.  I soon had to turn it off as the fierce wind was making it wobble, I re-started it after wedging a small quartz rock on the leeward side of the equipment.

 

The Trimble GeoHX on the summit of Dinas Mawr.

The route from this summit to the next proved torturous as I decided on a direct line that took me in to a forest of bramble.  After negotiating the slippery rock of a stone wall I headed up to the first of the 258m twin map height tops.  The high point consists of a long rock outcrop.

Looking back toward Dinas Mawr from Gallt y Celyn (SH 811 542).

By now more hail showers were massing and the next hit me as I was on the second 258m twin summit.  This consists of long grass on top of a large boulder.  The descent route was back on the inward track with the wind drying my clothes on the way.

The Trimble on the summit of the second of the 258m map heighted twin summits (SH 810 544)

Survey Result:


Dinas Mawr

Summit Height:  254.0m (converted to OSGM15)

Summit Grid Reference:  SH 80884 53931

Bwlch Height:  220.1m (converted to OSGM15)

Bwlch Grid Reference:  SH 80984 53980

Drop:  33.9m (200m Sub-Twmpau reclassified to 200m Twmpau)

Dominance:  13.35%

Gallt y Celyn (significant name change)

Summit Height:  257.6m (converted to OSGM15) 

Summit Grid Reference:  SH 81121 54259

Bwlch Height:  227.5m (converted to OSGM15, from subsequent Trimble GeoXH 6000 survey)

Bwlch Grid Reference:  SH 81548 54426 (from subsequent Trimble GeoXH 6000 survey)

Drop:  30.1m (converted to OSGM15) (200m Sub-Twmpau re-instated as 200m Twmpau after surveying the bwlch)

Dominance:  11.68%

Gallt y Celyn

Summit Height:  257.1m (converted to OSGM15)

Summit Grid Reference:  SH 81007 54476

Drop:  14m

Dominance:  5.45%

For the post detailing the bwlch survey of Gallt y Celyn please click {here}

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