Mapping Mountains – Hill Reclassifications – Humps

Mynydd y Drum (SN 820 108) – Subhump addition

This is the twenty ninth in a series of Hill Reclassification posts that detail hills whose status has been altered in the listing of the Humps (HUndred Metre Prominences) through map study and / or surveys and / or on-site visits that I have conducted.

The hill listed as Mynydd y Drum (SN 820 108) in the Humps

The hill name used in this and forthcoming posts is that used in the listing of Humps, therefore individual names and their composition may not match those that are used in listings I am directly associated with.  However, I am of firm belief that listed hill names used by other authors should be respected when giving detail within other people’s lists, however inappropriate some hill names may be considered.

This and forthcoming posts are retrospective as many of these hill reclassifications were initiated from studying the Ordnance Survey enlarged mapping that is hosted on the Geograph website, or in this instance from analysis of LIDAR data by Kevin McGovern and also independently by Aled Williams and then George Gradwell, resulting in an on-site visit when the hill was surveyed with the Trimble GeoXH 6000, and for the reclassifications that affected the Humps the on-site visit and survey of this hill took place on the 13.06.17.

The listing of Humps was published in book format by Lulu in 2009 and entitled More Relative Hills of Britain, its author; Mark Jackson gives credit to a number of people who contributed toward the formation of this list, these include; Eric Yeaman, Alan Dawson, Clem Clements, Rob Woodall, Bernie Hughes, Pete Ridges and others.  When the list was published in book format there were 2987 Humps listed with their criteria being any British hill that has 100m or more of drop, accompanying the main list is a sub category entitled Subhumps, with the criteria being any British hill that has 90m or more and below 100m of drop.

More Relative Hills of Britain by Mark Jackson

The details for the reclassification appear below:

There has been a reclassification to the listing of the Humps (HUndred Metre Prominences) instigated by analysis of LIDAR data by Kevin McGovern, Aled Williams and George Gradwell, resulting in an on-site visit when the hill was surveyed with the Trimble GeoXH 6000, with the latter taking place on the 13.06.17.

Prior to the survey with the Trimble GeoXH 6000 Mark Jackson had not listed this hill as it consists of waste spoil from the Nant Helen Opencast Mine that is now landscaped and it was only the analysis of LIDAR data that resulted in this hill being brought to the attention as a prospective Subhump addition.  For a detailed explanation of this hill, its height and those of adjacent hills please see Significant Height Revisions.

The hill appears under the name of Mynydd y Drum in the listing of the Humps, this is the name of the broad ridge that this and two other listed hills appear on.  When the on-site visit and survey took place I made place-name enquiries with two of the remaining six miners who still operate the opencast mine and they know the hill as Teisen Priodas, for a detailed explanation please refer to Significant Name Changes.

The hill is adjoined to the Fforest Fawr group and is situated overlooking the A 4067, A 4221 and A 4109 roads to the north-west, north-east and south-east respectively, and is positioned between the small communities of Abercraf (Abercrave) to the north and Coelbren towards the east.

This hill was surveyed using a Trimble GeoXH 6000 by Myrddyn Phillips on the 13.06.17 resulting in a 337.9m (converted to OSGM15) summit height and a 244.6m (converted to OSGM15) bwlch height, with these values giving this hill 93.3m drop, with photographs and a description of the on-site visit and survey being sent to George Gradwell who then initiated this hill’s addition as a Subhump.

The addition of this hill to Subhump status was accepted by Mark Jackson on the 14.06.17 and the listing of the Humps was updated accordingly.

The Trimble GeoXH 6000 gathering data at the summit of the hill listed as Mynydd y Drum in the Humps

The full details for the hill are:

Name:  Mynydd y Drum (as listed in the Humps)

Summit Height:  338.2m (as listed in the Humps)

OS 1:50,000 map:  160

OS 1:25,000 map:  12

Summit Grid Reference:  SN 820 108 (as listed in the Humps, SN 82013 10833 Trimble GeoXH 6000 set-up position)

Drop:  93.4m (as listed in the Humps) 

Myrddyn Phillips (November 2017)

Mapping Mountains – Significant Height Revisions – Y Trichant

Teisen Priodas (SN 820 108)

There has been a Significant Height Revision to a hill that is now listed in the Y Trichant due to analysis of LIDAR data by Kevin McGovern and also independently by Aled Williams and George Gradwell, which was subsequently confirmed by a survey with the Trimble GeoXH 6000 that was conducted on the 13th June 2017. 

Y Trichant is the title for the hills in the 300m height band of the Twmpau (thirty welsh metre prominences and upward) and takes in all Welsh hills at or above 300m and below 400m in height that have a minimum 30m of drop, with the introduction to the re-naming of this list appearing on Mapping Mountains on the 13^th May 2017.

The ridge that this hill is a part of is named Mynydd y Drum and it consists of three listed hills, one being a sub hill which is deemed natural, and two being P30s that are the consequence of mine workings, with one of these P30s having been fully landscaped.  It is this fully landscaped P30 whose details are given in this article.  

When visiting this hill I made place-name enquiries with two of the remaining six mine workers and was told that the name the hill is known by is Teisen Priodas, which translated into English means the wedding cake, an apt name as the hill has three tiers and is relatively flat on top.

Teisen Priodas is adjoined to the Fforest Fawr group, with its Cardinal Hill being Fan Gyhirych (SN 880 191) and is placed in the Region of South Wales (Region C, Sub-Region C2), with the hill positioned between the small communities of Abercraf (Abercrave) to the north and Y Coelbren towards the east.

As the hill is a part of the Nant Helen Opencast Mine permission to visit should be sought, however Ordnance Survey maps still show public footpaths crossing the opencast workings with the nearest one placed just to the west of the summit and crossing land associated with the mine from a south to a north direction, this public footpath is probably on a part of land that has been landscaped.

Teisen Priodas consists of waste spoil that is now landscaped, and as it is customary for Ordnance Survey maps to show mine workings without any form of contour line the hill had not been classified prior to the analysis of LIDAR data, although the area of this hill’s bwlch does possess contours.  The mine is situated on the north-eastern part of the Mynydd y Drum ridge, with the south-western part of this broad ridge still intact having not been mined and possessing a 200m Sub-Twmpau that is listed by the name of Mynydd y Drum.

The highest ring contour shown on Ordnance Survey 1:25,000 Explorer maps for the whole  broad ridge of Mynydd y Drum is 290m which appears on the south-western part of this ridge where the 296.2m summit of the Sub-Twmpau is situated at SN 80718 09753, and also at the eastern periphery of the mine at SN 833 112.  

The survey with the Trimble GeoXH 6000 produced a summit height for Teisen Priodas of 337.9m (converted to OSGM15) which comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revision applies to any listed hill whose Ordnance Survey summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000, or a previous estimated summit height based on interpolation of contours.  Also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble.  As heights on different scaled Ordnance Survey maps are not consistent the height given on the 1:25,000 map is being prioritised in favour of the 1:50,000 map for detailing these revisions.

The summit area of this hill is now landscaped and relatively flat and expansive, with the high point toward the eastern part of the summit plateau which consists of long grasses.

Therefore this hill’s new summit height is 337.9m (converted to OSGM15), as no summit contours exist for this hill above the 290m given to the far eastern part of the mine workings on the Ordnance Survey 1:25,000 Explorer map, this is a dramatic 47.9m increase in height compared to its uppermost ring contour. 

The full details for the hill are:

Cardinal Hill:  Fan Gyhirych 

Summit Height (New Height):  337.9m (converted to OSGM15)

Name:  Teisen Priodas

OS 1:50,000 map:  160

Summit Grid Reference:  SN 82013 10833

         

Drop:  93.3m (converted to OSGM15)

The Trimble GeoXH 6000 gathering data at the summit of Teisen Priodas (SN 820 108) which confirmed this hill's significant height revision

For details on the Hill Reclassification post instigated from analysis of LIDAR data

For details on the survey that confirmed this hill's significant height revision

Myrddyn Phillips (August 2017)

Mapping Mountains – Significant Name Changes – Y Trichant

Teisen Priodas (SN 820 108)

There has been a Significant Name Change to a hill that is listed in the Y Trichant, with the summit height, drop and status of the hill being confirmed by a Trimble GeoXH 6000 survey which took place on the 13^th June 2017. 

The criteria for the list that this name change applies to are:

Y Trichant - These are the Welsh hills at and above 300m and below 400m in height that have 30m minimum drop,  with the introduction to the re-naming and publication history of this list appearing on Mapping Mountains on the 13^th May 2017.

The hill is adjoined to the Fforest Fawr range, this group of hills is situated in the north-western part of South Wales (Region C, Sub-Region C2), and it is positioned above the small community of Abercraf (Abercrave) to the north and Blaendulais (Seven Sisters) to the south. 

Teisen Priodas (SN 820 108)

The hill forms a part of the ridge known as Mynydd y Drum, this ridge has been extensively mined in its north-eastern section with the remaining highest natural summit positioned at SN 80718 09753 and listed as a 200m Sub-Twmpau under the name of Mynydd y Drum.

The hill is a part of the Nant Helen Opencast Mine and consists of landscaped waste spoil and its detection was dependent upon LIDAR data analysed by Kevin McGovern and then independently by Aled Williams and also by George Gradwell.  Prior to analysis of LIDAR data the hill had not appeared in any list, due to these analyses it was subsequently included in the Y Trichant.  

Extract from the Ordnance Survey 1:25,000 Explorer map with the expended ridge name of Mynydd y Drum and the extent of the Nant Helen Opencast Mine

When this hill was listed as a Trichant it appeared under the name of the extended ridge it is a part of; Mynydd y Drum, however after surveying it with the Trimble GeoXH 6000 I had the opportunity to discuss its name with workers at the Nant Helen Opencast Mine.

After visiting this hill I entered the workings of the Nant Helen Opencast Mine hoping to visit the adjacent north-easterly P30 and also make place-name enquiries, I was approached by two mine employees in separate vehicles, after apologising for being where I was I asked them about the name of the two new P30s, each of which is the result of mine spoil, both knew the higher hill as Teisen Priodas, this is translated into English as the wedding cake, an apt name as the hill consists of three tiers and is relatively flat on top.

Therefore, the name this hill is now listed by in the Y Trichant is Teisen Priodas, with this name being prioritised over that of Mynydd y Drum as the former is a locally known name for an individual hill and the latter is the name given to the extended ridge that now consists of three individual hills; two of them being P30s and one being a sub P30. 

The full details for the hill are:

Group:  Fforest Fawr

Name:  Teisen Priodas

Previously Listed Name:  Mynydd y Drum 

Summit Height:  337.9m (converted to OSGM15)

OS 1:50,000 map:  160

Summit Grid Reference:  SN 82013 10833  

Drop:  93.3m (converted to OSGM15)

For details on the survey of Teisen Priodas

Myrddyn Phillips (August 2017)

Mapping Mountains – Trimble Surveys – Fforest Fawr

13.06.17  Mynydd y Drum (SN 807 097), Teisen Priodas (SN 820 108) and MRF Tip (SN 828 114, not Trimbled)

Teisen Priodas (SN 820 108)

To my knowledge it was Kevin McGovern who first analysed the ridge known as Mynydd y Drum via LIDAR data, the result being that although the south-western point still exists and is deemed natural, the north-eastern part of the ridge has been dramatically altered due to the workings of the Nant Helen Opencast Mine, with the mining activities having produced two new P30s, one of which is landscaped and higher than the remaining south-westerly natural high point, whilst the second new P30 is further north-west.  Aled Williams then used LIDAR data to analyse these hills and furthermore George Gradwell then did so, their results matched those obtained by Kevin McGovern.  The timeframe for these analyses spanned six months and it seemed no one from the hill bagging community had ventured to these hills for an on-site inspection, and although each had been documented as Hill Reclassifications in the Twmpau with one P30 becoming a sub and two P30 additions, I thought it time to visit these hills, and with the forecast for Wales predicting better weather in the south of the country this instilled enthusiasm for me to visit.

Parking on the outskirts of Y Coelbren next to the A 4221 road I turned the Trimble on and headed toward the coordinates for the ten figure grid reference obtained via LIDAR data for the bwlch position of the highest point and still relatively new P30.  I found this beside a hedge, or to be precise it was in or under a thick and untidy hedge consisting of all manner of exotic plants, including hawthorn, my only option was to set the Trimble up beside the hedge and gather the customary five minutes of data.

Gathering data at the critical bwlch of Teisen Priodas

Once the equipment was packed away I drove the short distance to the start of my walk and followed a paved road toward the first hill, this road continues to the buildings of the Nant Helen Opencast Mine.  I left the paved road to follow a track designated a public footpath that led toward the south-westerly hill listed as Mynydd y Drum and which is the remaining highest natural summit on the ridge.

It felt good to be out with an objective for the day, on ground that I had not been on before with views farther south to hills that one day I hoped to visit.  Nearing the summit of Mynydd y Drum I quietly passed a herd of grazing cows and then came across a number of friendly horses and although a great number of each remained close to the summit of the hill whilst I Trimbled it, the survey took place without disturbance.

Approaching the summit of Mynydd y Drum

Gathering data at the summit of Mynydd y Drum

Gathering to inspect the Trimble

My next objective was the connecting bwlch between the hill listed as Mynydd y Drum and the highest and still relatively new and landscaped P30, without the aid of the ten figure grid reference produced by LIDAR data I would probably have been a good few metres from the critical point in the Trimble set-up position, even with the ten figure grid reference I still spent a number of minutes wandering round in a bog slowly zeroing in to the correct placement.  After the allotted five minutes of data were gathered I switched the equipment off, packed it away and headed toward the steepening ground consisting of three landscaped tiers of what is now the high point of the Mynydd y Drum ridge.

Gathering data at the critical bwlch of Mynydd y Drum

This new high point is large in area and is now landscaped, I passed an open drainage duct that resembled a water shoot on my way up and proceeded to the relatively flat summit area, I again used the Trimble as a hand help GPS to zero in to the summit coordinates, five minutes of data were duly collected and before leaving I took compass readings toward where the next connecting bwlch lay and the summit of the last P30.

The drainage duct on the south-west slope of Teisen Priodas

Mynydd y Drum from Teisen Priodas

As I crested the lip of the summit plateau I realised that reaching the last P30 may prove problematic as there were a number of vehicles parked outside a large building and machinery chugged away close to it, the mine was still operational, which was a surprise as I’d found a BBC report the previous evening that mentioned that the mine was to be mothballed with the loss of a number of jobs.  Realising that I should not be where I was, I decided to at least walk toward the workings and see if I could ask permission to visit the next P30 hill.

The whole summit plateau of Teisen Priodas is vegetated with foxgloves adding colour to the scene

Gathering data at the summit of Teisen Priodas

MRF Tip from the eastern slopes of Teisen Priodas

Descending steeply down the eastern grassed slopes I crossed a drainage stream coloured a murky looking orangey yellow and clambered up to a dirt track leading to where coal was pouring out of large stationary machinery, I spotted a mine vehicle and headed toward it but gave up as the only way to reach it was past the heavy machinery, the next bwlch I hoped to survey was somewhere near this point and deciding against further progress in this direction I opted for a safer route and back-tracked a few metres and walked up a grassed and landscaped slope and down steeply to another drainage channel and up the other side to a track leading to the main mine building.

Approaching the mine workings

Heading toward the main mine building

Teisen Priodas from the Nant Helen Opencast Mine

I walked round the building looking for someone to ask permission for onward progress, no one was there so I hesitantly carried on and walked up the mine track leading to the top of the last P30, I stopped when a vehicle headed up the same way, I waved and walked a few metres down to it. 

Beside the mine building

Just below the summit of MRF Tip

The person driving the vehicle was friendly and I apologised for being where I was, a few minutes later and another vehicle pulled up, we chatted for twenty minutes or so about the mines history, the loss of jobs, the remaining skeletal staff of six, and the Trimble and place-name research.  They both knew the higher landscaped hill as Teisen Priodas, which translated into English means the wedding cake, an apt name as the hill has three tiers and is relatively flat on top, with the hill I was on my way up being known as MRF Tip.  However much cajoling I did I could not get permission to visit the summit and Trimble it, this was understandable as I should not have been where I was, however one of them kindly offered to drive me over the summit and back down to my car, passing over the summit I looked out on small piles of waste spoil dotted about resembling a lunar landscape, on the way down I was advised to contact Celtic Energy to seek permission to visit the mine with the potential of surveying the last P30; MRF Tip.

Survey Result:

Mynydd y Drum

Summit Height:  296.2m (converted to OSGM15)  

Summit Grid Reference:  SN 80718 09753

Bwlch Height:  271.4m (converted to OSGM15)

Bwlch Grid Reference:  SN 81526 10519

Drop:  24.8m (200m Twmpau reclassified to 200m Sub-Twmpau confirmed)

Dominance:  8.38%

Teisen Priodas (significant name change) 

Summit Height:  337.9m (converted to OSGM15) (significant height revision) 

 

Summit Grid Reference:  SN 82013 10833

Bwlch Height:  244.6m (converted to OSGM15)

Bwlch Grid Reference:  SN 84569 11383

Drop:  93.3m (Trichant addition confirmed) (Subhump addition confirmed)

Dominance:  27.61%

For further details please consult the Trimble Survey Spreadsheet

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

Teisen Priodas (SN 820 108) - Trichant addition

There has been an addition to the listing of the Y Trichant, these are the hills within the 300m height band of the Twmpau (thirty welsh metre prominences and upward) due to analysis of LIDAR data by Kevin McGovern and also independently by Aled Williams, and subsequently confirmed via a survey with the Trimble GeoXH 6000.  With the high point of the hill previously listed in the 200m height band when the Welsh P30 hills below 500m in height were published on Geoff Crowder’s v-g.me website.

The hill had been listed with a 297m summit height positioned at SN 807 098 based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map numbers 12 and 165, whilst the Ordnance Survey 1:50,000 Landranger map number 160 gives a 298m summit spot height at the same position.  This latter spot height is derived from the 978.1ft (298.1ft) height on the Ordnance Survey old Six-Inch map.

When this hill was originally listed in the Welsh P30 lists on the v-g.me website it had an accompanying note which stated ‘3 points of 300m on 1985 map may probably no longer exist (quarrying)’.  The hand written Master Lists stated ‘Due to opencast workings the three points of 300c at GR 830 112 on 1985 1:50,000 map probably no longer exist’.  These three points are in the vicinity of where a 984ft (299.9m) height appears on the Ordnance Survey old Six Inch map and in all likelihood signified where the summit of this hill was once positioned.  Since this time the Nant Helen Openacast Mine workings which take in the northern and eastern part of the ridge known as Mynydd y Drum have destroyed the old 984ft (299.9m) summit, but in its place are two new P30 summits comprising the spoil from the mine workings, with this Hill Reclassifications post concentrating on the higher of these two artificial summits, whilst the 296.2m (converted to OSGM15) natural summit at SN 80718 09753 and listed as Mynydd y Drum still remains. 

  

Prior to analysis of LIDAR data the ridge known as Mynydd y Drum was listed with one summit, the opencast mine has now created a further two summits which are artificial and comprise the remains of waste spoil, the summit which this Hill Reclassifications post details is now higher than the previously listed summit, resulting in new bylchau heights and positions and also drop values for these three hills, all of these will be detailed in this and two further Hill Reclassifications posts, with the name Teisen Priodas being found from local enquiry and the other two hills being Mynydd y Drum (SN 807 097) and MRF Tip (SN 828 114).

The hill is adjoined to the Fforest Fawr group with its Cardinal Hill being Fan Gyhirych (SN 880 191) and is placed in the Region of South Wales (Region C, Sub-Region C2), and it is positioned between the small communities of Abercraf (Abercrave) to the north and Y Coelbren towards the east.

The summit of the hill is situated within the Nant Helen Opencast Mine so permission to visit the high point should be sought, however it has open access land to its south-west and a public footpath marked on Ordnance Survey maps that heads in a north- south direction and at its closest point is just to the west of the summit of this hill.

The name of the hill is Teisen Priodas and its reclassification to a Trichant is due to the analysis of LIDAR data by Kevin McGovern and also independently by Aled Williams.  LIDAR (Light Detection & Ranging) is highly accurate height data that is now freely available for much of England and Wales.

Kevin’s analysis of LIDAR data gives the hill the following details:

Teisen Priodas

Summit Height:  338.2m (converted to OSGM15)

Summit Grid Reference:  SN 82014 10832

Bwlch Height:  244.8m (converted to OSGM15)

Bwlch Grid Reference:  SN 84566 11384

Drop:  93.4m

Therefore, the 338.2m LIDAR data produced for the summit position at SN 82014 10832 and the 244.8m LIDAR data produced for the bwlch position at SN 84566 11384 is sufficient for this hill to be classified as a Trichant with 93.4m of drop and for it to be listed with a higher summit than the 296.2m (converted to OSGM15) summit of Mynydd y Drum at SN 80718 09753, with the details from the Trimble GeoXH 6000 survey being 337.9m (converted to OSGM15) summit at SN 82013 10833 and 244.6m (converted to OSGM15) bwlch at SN 84569 11383, giving this hill 93.3m of drop.

This now revises the total in the Y Trichant and the Twmpau which will be updated accordingly.

The full details for the hill are:

Cardinal Hill:  Fan Gyhirych

Summit Height:  337.9m (converted to OSGM15, Trimble data)

Name:  Teisen Priodas

OS 1:50,000 map:  160

Summit Grid Reference:  SN 82013 10833 

  

Drop:  93.3m (converted to OSGM15, Trimble data)

Teisen Priodas (SN 820 108) a new addition to the Y Trichant list

My thanks to Mark Jackson for bringing the details of this hill to my attention and to Kevin McGovern and Aled Williams for their analysis of LIDAR data.

Myrddyn Phillips (March 2017)