Mapping Mountains – Hill Reclassifications – The 500-Metre Tops of England and Wales – Deweys

Cefn Cyfarwydd (SH 752 630) – Dewey addition

This is one in a series of retrospective Hill Reclassification posts that detail hills whose status has altered in the listing of the Deweys and where I have had direct association with the status change.  These posts will tie in with a forthcoming Change Register giving detail to this list and its alterations since publication in the Mountain tables book.

Cefn Cyfarwydd (SH 752 630)

The 500-Metre Tops of England and Wales are affectionately known after their hill list compiler; Michael Dewey.  This list mixes metric and imperial height in its criteria to bookend up to the 2000ft height band and takes in all hills in England, Isle of Man and Wales that are 500m and above and below 2000ft (609.6m) in height that have 30m minimum drop.

This list formed one of a number of lists that appeared in the Mountain tables book published by Constable in 1995 and at the time of publication comprised 373 hills with 164 in England, 5 in the Isle of Man and 204 in Wales.  The Deweys have undergone extensive revision since first publication with the initial stages forming the basis of this revision given below:

1995    Mountain tables published by Constable with 373 hills listed as Deweys.

April 2000    Strider (LDWA quarterly booklet) publishes contact details for David Purchase and Myrddyn Phillips who have found and list 24 and 14 possible new 500m tops respectively.

It was expanded versions of the above two lists that formed the basis of the next publication:

25^th May 2000    List of Possible 500 Metre Tops by Michael Dewey listing 44 hills.

David Purchase expands his Additional Dewey 500m Hills and Myrddyn Phillips produces lists of English 500m hills to measure and Welsh 500m hills to measure.

These lists formed the basis of the next publication:

29^th June 2000    Possible/Probable 500’s by Michael Dewey listing 77 hills.  Michael adopts following protocol; if one person proposes that a top should qualify as a 500 by personal survey, and is then confirmed by a second person, it should then be promoted to the main list.

April 2002    The 500+ Tops of England and Wales – The ‘New Deweys’ published in the Strider booklet and listing 66 new qualifying hills.

25^th May 2006    Rob Woodall republishes Michael’s main and possible/probable lists on the RHB Yahoo group file database. 

Mountain tables by Michael Dewey

The details for this addition appear below:

The name the hill is listed by in the Deweys is Cefn Cyfarwydd, and it is adjoined to the Carneddau group of hills which are situated in the north—western part of north Wales, and it is positioned with a minor road to its north and south-east, and farther afield has the B5106 and the A470 roads to its east, and has the village of Trefriw towards the east and the town of Llanrwst towards the east south-east.

This hill was not included in the original 1995 Constable publication, as with a 503m summit spot height and a 477m bwlch spot height that appear on the Ordnance Survey 1:25,000 Explorer map it was accepted that the hill had under 30m of drop.

Extract from the Ordnance Survey 1:25000 Explorer map

Since the 1995 publication of this list by Constable there have been a number of Ordnance Survey maps made available online, some of these are historic such as the series of Six-Inch maps on the National Library of Scotland website, whilst others are current and digitally updated such as the mapping on the OS Maps website.  This is the replacement for OS Get-a-map and has contours at 5m intervals which are proving consistently more accurate compared to the 5m contours that sometimes appear on Ordnance Survey 1:25,000 Explorer maps and used to appear on the online Vector Map Local.  This mapping shows the 477m bwlch spot height to be positioned on a separate 475m contour ring implying that the height of this hill’s bwlch is substantially lower than 477m, with interpolation based on this contouring giving the hill an estimated c 30m of drop.

Extract from the OS Maps website

With this newly acquired information the hill was prioritised for a GNSS survey and this took place on the 17^th February 2019.  The summit and bwlch of this hill were surveyed by Myrddyn Phillips and Aled Williams using a Trimble GeoXH 6000 resulting in a 501.7m summit height and a 471.0m bwlch height, with these values giving this hill 30.7m of drop. 

The Trimble GeoXH 6000 gathering data at the summit of Cefn Cyfarwydd

The Trimble GeoXH 6000 gathering data at the bwlch of Cefn Cyfarwydd

These details were forwarded to the list author; Michael Dewey and the hill was subsequently added to his list on 19^th February 2019.

 

The full details for the hill are:

Name:  Cefn Cyfarwydd

OS 1:50,000 map:  115

OS 1:25,000 map:  17

Summit Height:  501.7m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SH 75201 63067 (Trimble GeoXH 6000)

Bwlch Height:  471.0m (converted to OSGM15, Trimble GeoXH 6000)

Bwlch Grid Reference:  SH 74708 62751 (Trimble GeoXH 6000)

Drop:  30.7m (Trimble GeoXH 6000)

Myrddyn Phillips (October 2020)

Mapping Mountains – Hill Reclassifications – Y Pedwarau - The 400m Hills of Wales

Cefn Cyfarwydd (SH 752 630) – 500m Double Sub-Pedwar reclassified to 500m Sub-Pedwar

There has been a reclassification of a hill that is listed in the Y Pedwarau, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by a survey with the Trimble GeoXH 6000 conducted by Myrddyn Phillips and Aled Williams which took place on the 17^th February 2019.

Cefn Cyfarwydd (SH 752 630)

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

Y Pedwarau – Welsh hills at or above 400m and below 500m in height with 30m minimum drop, accompanying the main Y Pedwarau list are five categories of sub hills, with this hill being reclassified from a 500m Double Sub-Pedwar to a 500m Sub-Pedwar.  The criteria for 500m Double Sub-Pedwar status being all Welsh hills at or above 500m and at or below 510m in height that have 20m or more and below 30m of drop, with the criteria for 500m Sub-Pedwar status being all Welsh hills at or above 500m and at or below 510m in height with 30m minimum drop.  The list is a joint compilation between Myrddyn Phillips and Aled Williams and is published on Mapping Mountains in Google Doc format.

The name of the hill is Cefn Cyfarwydd, and it is adjoined to the Carneddau group of hills, which are situated in the north-western part of North Wales (Region A, Sub-Region A1), and it is positioned with the A5 road to its south and the B5106 and the A470 roads and the Afon Conwy to its east, and has the villages of Trefriw and Llanrwst towards the east.  

Prior to the survey with the Trimble GeoXH 6000 this hill was listed with 26m of drop based on the 503m summit and 477m bwlch spot heights that appear on the Ordnance Survey 1:25,000 Explorer map.

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

The details for this hill were re-assessed when the Ordnance Survey Vector Map Local hosted on the Geograph website became available online; this mapping is entitled the Interactive Coverage Map.  As this mapping is larger in format it enables a better judgement of interpolated heights and it occasionally has contours at 5m intervals compared to the 10m contour intervals normally shown on the 1:25,000 Explorer map.  However, this mapping has the same spot heights and 10m contouring as the 1:25,000 Explorer map and therefore the drop value for this hill remained listed as 26m.

The area taking in this hill was re-examined when the OS Maps website became available online.  This is the replacement for OS Get-a-map and has contours at 5m intervals.  This mapping shows the 477m bwlch spot height to be positioned on a separate 475m contour ring implying that the height of this hill’s bwlch is substantially lower than 477m, with interpolation based on this contouring giving the hill c 30m of drop.  But it was not until the survey with the Trimble GeoXH 6000 that the increased drop value was confirmed.

Extract from the OS Maps website

The reclassification of Cefn Cyfarwydd from 500m Double Sub-Pedwar status is due to a survey with the Trimble GeoXH 6000, resulting in a 501.7m summit height and a 471.0m bwlch height, with these values giving this hill 30.7m of drop which is sufficient for it to be classified as a 500m Sub-Pedwar.

The Trimble GeoXH 6000 gathering data at the summit of Cefn Cyfarwydd

The full details for the hill are:

Group:  Carneddau

Name:  Cefn Cyfarwydd

OS 1:50,000 map:  115

Summit Height:  501.7m (converted to OSGM15)

Summit Grid Reference:  SH 75201 63067

Bwlch Height:  471.0m (converted to OSGM15)

Bwlch Grid Reference:  SH 74708 62751

Drop:  30.7m

For the additions, reclassifications and deletions to Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the available and following Change Registers:

Y Pedwarau

Y Pedwarau – 400m Sub-Pedwarau

Y Pedwarau – 390m Sub-Pedwarau

Y Pedwarau – 390m Double Sub-Pedwarau

For details on the survey of this hill

Myrddyn Phillips and Aled Williams (July 2019)

Mapping Mountains – Hill Reclassifications – 500m Twmpau

Cefn Cyfarwydd (SH 752 630) – 500m Sub-Twmpau reclassified to 500m Twmpau

There has been a reclassification of a hill that is listed in the 500m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by a survey with the Trimble GeoXH 6000 conducted by Myrddyn Phillips and Aled Williams which took place on the 17^th February 2019.

Cefn Cyfarwydd (SH 752 630)

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

500m Twmpau - Welsh hills at or above 500m and below 600m in height with 30m minimum drop, with an accompanying sub list entitled the 500m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 500m and below 600m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

The name of the hill is Cefn Cyfarwydd, and it is adjoined to the Carneddau group of hills, which are situated in the north-western part of North Wales (Region A, Sub-Region A1), and it is positioned with the A5 road to its south and the B5106 and the A470 roads and the Afon Conwy to its east, and has the villages of Trefriw and Llanrwst towards the east.  

Prior to the survey with the Trimble GeoXH 6000 this hill was listed with 26m of drop based on the 503m summit and 477m bwlch spot heights that appear on the Ordnance Survey 1:25,000 Explorer map.

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

The details for this hill were re-assessed when the Ordnance Survey Vector Map Local hosted on the Geograph website became available online; this mapping is entitled the Interactive Coverage Map.  As this mapping is larger in format it enables a better judgement of interpolated heights and it occasionally has contours at 5m intervals compared to the 10m contour intervals normally shown on the 1:25,000 Explorer map.  However, this mapping has the same spot heights and 10m contouring as the 1:25,000 Explorer map and therefore the drop value for this hill remained listed as 26m.

The area taking in this hill was re-examined when the OS Maps website became available online.  This is the replacement for OS Get-a-map and has contours at 5m intervals.  This mapping shows the 477m bwlch spot height to be positioned on a separate 475m contour ring implying that the height of this hill’s bwlch is substantially lower than 477m, with interpolation based on this contouring giving the hill c 30m of drop.  But it was not until the survey with the Trimble GeoXH 6000 that the increased drop value was confirmed.

Extract from the OS Maps website

The reclassification of Cefn Cyfarwydd to 500m Twmpau status is due to a survey with the Trimble GeoXH 6000, resulting in a 501.7m summit height and a 471.0m bwlch height, with these values giving this hill 30.7m of drop which is sufficient for it to be classified as a 500m Twmpau.

The Trimble GeoXH 6000 gathering data at the summit of Cefn Cyfarwydd

The full details for the hill are:

Group:  Carneddau

Name:  Cefn Cyfarwydd

OS 1:50,000 map:  115

Summit Height:  501.7m (converted to OSGM15)

Summit Grid Reference:  SH 75201 63067

Bwlch Height:  471.0m (converted to OSGM15)

Bwlch Grid Reference:  SH 74708 62751

Drop:  30.7m

For details on the survey of Cefn Cyfarwydd

Myrddyn Phillips (July 2019)

Mapping Mountains – Trimble Surveys – Carnedd Llywelyn

17.02.19  Cribau (SH 732 641), Pt. 504.7m (SH 744 624) and Cefn Cyfarwydd (SH 752 630)

Cefn Cyfarwydd (SN 752 630)

Much of the north-eastern Carneddau are a world apart compared to their higher adjacent hills as their land is dominated by heather which always gives an added sense of wilderness.  These hills stretch from the higher peaks of Creigiau Gleision and Pen Llithrig y Wrach north-eastward toward the coastal plains of the Afon Conwy.

Along with Aled and Mark we planned to visit three of these hills with each being surveyed.  Two of which are marginal P15s and are listed in the Welsh Highlands list (Yr Uchafion) whilst the third; Cefn Cyfarwydd is a potential new Dewey with OS Maps indicating that the 477m bwlch spot height that appears on the Ordnance Survey 1:25,000 Explorer map is in fact on a separate contour ring implying that the critical bwlch is significantly lower.

We met in Trefriw and spent an hour in a café enjoying conversation and laughs over breakfast as the forecast rain materialised.  It was around 10.00am as we indulged in our morning meal, and the rain was forecast to continue until at least midday.  After breakfast Mark drove on the narrow road toward Llyn Cowlyd were he parked and we sat in his car watching the rain and wind sweep in and batter the land around us.

Met office weather forecasts can be incredibly accurate and we had our boots on, or in my case my wellies, and walking in dull but dry conditions by 12.20pm, following the track heading up toward an old quarry above the northern part of Llyn Cowlyd.

The first hill on the surveying agenda was Cribau, which we’d all previously visited, a long time ago for me when I surveyed it with my basic levelling staff.  It has an attractive summit consisting of two tops, each was surveyed and although the rain had stopped the strong wind was still present and I hoped that the Trimble would remain in place during the five minutes data collection on each top.

Gathering data at the first position surveyed for the summit of Cribau

Between the two tops of Cribau

Gathering data at the second position surveyed for the summit of Cribau

I’ve always enjoyed this north-eastern land of the Carneddau with its rock carved summits and thick heather, few people seem to visit these hills compared to their easier underfoot higher neighbours and they have a feel of remoteness and solitude enhanced by the elongated lake of Llyn Cowlyd, which today glistened with brief bursts of sunlight giving a silvery sheen to the grey cloud and rising hillsides above.

Gathering data at the critical bwlch of Cribau

Llyn Cowlyd

Our downward route consisted of the customary bit of heather bashing before the inward track was re-joined; this brought us down to the dam of Llyn Cowlyd from where a convenient path continued through the heather gaining height toward our next point to survey; the bwlch of a c 500m hill positioned between Creigiau Gleision and Cefn Cyfarwydd.

Mark heading up toward the Cefn Cyfarwydd ridge

Pen Llithrig y Wrach rising above Llyn Cowlyd

The bwlch was positioned in a flat-bedded bog and I was thankful for my chose of footwear, which for winter walking in the climate and conditions that lovely Wales sometimes offers are a must.

Gathering data at the critical bwlch of Pt. 504.7m (SH 744 624)

Once five minutes of data were gathered I followed Aled and Mark through the heathery surrounds to the hill’s summit, which consists of three potential high points, with two of these were judged to be candidates for the true summit, they were duly surveyed.

Gathering data at the first position surveyed for the summit of Pt. 504.7m

Gathering data at the second position surveyed for the summit of Pt. 504.7m

By now the grey overhead conditions that had followed immediately after the rain had been replaced by blue sky and a chilling afternoon strong breeze.  During the two summit surveys Mark headed down to investigate the area of the critical bwlch for Cefn Cyfarwydd.  This hill now shone in the afternoon light, a bulk of a hill that looked from this vantage point to easily have the required minimum 30m of drop to qualify for Dewey status.

As I stood upon the summit that had just been Trimbled long shadows cast out against the heather at my feet with Cefn Cyfarwydd beyond.  Once the Trimble was packed away I followed Aled through the rough heather toward a welcoming path that eased passage down toward the area of the connecting bwlch.

Cefn Cyfarwydd

This bwlch consisted of two lines of land that curved round an intermediary heathery bump, whilst Mark succumbed to the pleasures of lying in copious amounts of heather, Aled and I assessed the land and decided that two surveys were required, one from either side of the heathery bump with the placement of the Trimble nearer Cefn Cyfarwydd our favoured position for the critical bwlch of this hill.

Gathering data at the critical bwlch of Cefn Cyfarwydd

It was now 4.30pm and as I followed Mark and Aled up toward the summit of Cefn Cyfarwydd banks of cloud had pushed in from the south-west and any remaining blue sky was now positioned to our north over the sea.

Moel Siabod (L), Creigiau Gleision (centre) and Pen Llithrig y Wrach (R)

It felt good to be on this hill determining its drop after comparing its bwlch spot height against the 5m contouring on OS Maps.  Map research can often give the prospect for interesting survey results and my inclination before processing the Cefn Cyfarwydd data is that it will have sufficient drop to qualify for Dewey status.

As I approached the top of Cefn Cyfarwydd Aled and Mark were standing on its high point which consists of a slight heathery rise amongst more heather.  The Trimble was soon positioned on Aled’s rucksack to give it elevation above its immediate surrounds, the measurement offset noted and the 0.1m accuracy level before data should be logged was soon attained, I now waited for the allotted five minutes of data to be gathered and stored.

Gathering data at the summit of Cefn Cyfarwydd

All that remained was the walk down the hill on what proved to be a good path that led on to the narrow lane which culminated at the continuation of the track leading toward Mark’s car which was parked close to Llyn Cowlyd.

The walk back

As I sauntered toward the car the wind whipped down the valley and the landscape looked stunning in the dusk light.  I slowly plodded my way back on the track happy to be out in such a place. 

Survey Result:

Cribau

Summit Height:  501.9m (converted to OSGM15)

Summit Grid Reference:  SH 73264 64129

Bwlch Height:  487.3m (converted to OSGM15)

Bwlch Grid Reference:  SH 73056 63919

Drop:  14.6m (Uchaf reclassified to 500m Sub-Uchaf)

Dominance:  2.90%

Pt. 504.7m

Summit Height:  504.7m (converted to OSGM15)

Summit Grid Reference:  SH 74482 62452

Bwlch Height:  491.4m (converted to OSGM15)

Bwlch Grid Reference:  SH 74150 62406

Drop:  13.3m (Uchaf deletion)

Dominance:  2.64%

Cefn Cyfarwydd

Summit Height:  501.7m (converted to OSGM15)

Summit Grid Reference:  SH 75201 63067

Bwlch Height:  471.0m (converted OSGM15)

Bwlch Grid Reference:  SH 74708 62751

Drop:  30.7m (500m Sub-Twmpau reclassified to 500m Twmpau) (500m Double Sub-Pedwar reclassified to 500m Sub-Pedwar) (Dewey addition)

Dominance:  6.11%

For further details please consult the Trimble Survey Spreadsheet