Mapping Mountains – Significant Name Changes – 100m Twmpau

The Pimple (SJ 299 472)

There has been a Significant Name Change to a hill that is listed in the 100m Twmpau, and the following details are in respect of a hill that was surveyed with the Trimble GeoXH 6000 on the 20^th October 2015.

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

100m Twmpau - All Welsh hills at and above 100m and below 200m in height that have 30m minimum drop, with an accompanying sub category entitled the 100m Sub-Twmpau taking in all Welsh hills at and above 100m and below 200m in height that have 20m and more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

The hill is a part of the Moel y Gamelin range; this group of hills are situated in the north-eastern part of north Wales.  The hill is positioned above the B 5426 and B 5605 roads and is situated on the northern outskirts of Rhosllanerchrugog.

The Trimble GeoXH 6000 gathering data at the summit of The Pimple

Prior to the survey with the Trimble GeoXH 6000 the hill was not classified as it had not appeared in any known listing of hills.  Therefore, although there is no change in this hill’s listed name it is worth categorising under the heading of Significant Name Changes as the name this hill is now listed by comes from local enquiry, with the hill's height and classification being confirmed by the survey with the Trimble GeoXH 6000.   

    

Extract from the current Ordnance Survey 1:50,000 Landranger map

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

Therefore, the name this hill is now listed by in the 100m Twmpau is The Pimple, and this is a locally known name for the summit of the hill and is known as such by the family who live in the house directly below the hill to the west, beside the area of the hill’s bwlch.  The house used to be the office of the old mine that operated on a part of the hill, with the family of the current residents having lived here for five generations and with the name of The Pimple having been used for many years. 


The full details for the hill are:

Group:  Moel y Gamelin

Name:  The Pimple

Previously Listed Name:  Previously not classified 

Summit Height:  153.5m (converted to OSGM15)

OS 1:50,000 map:  117

Summit Grid Reference:  SJ 29984 47262 

 

Drop:  25.2m (converted to OSGM15)

For details on the survey of The Pimple

Myrddyn Phillips (September 2016)

Mapping Mountains – Significant Height Revisions – 100m Twmpau

The Pimple (SJ 299 472)

There has been a Significant Height Revision initiated by a survey with the Trimble GeoXH 6000 to the listing of the 100m Twmpau, with these details being retrospective as the survey that resulted in this height revision was conducted on the 2oth October 2015.

The criteria for the listing that this height revision affects are:

100m Twmpau - These are the Welsh hills at or above 100m and below 200m in height that have a minimum drop of 30m.  The word Twmpau is an acronym for thirty welsh metre prominences and upward.  The criteria for 100m Sub-Twmpau status are all Welsh hills at or above 100m and below 200m in height with 20m or more and below 30m of drop. 

The name of the hill is The Pimple; this is a locally known name which was given me when I made enquiries during the survey for the bwlch position of the hill.  The hill remains unnamed on Ordnance Survey maps and its locally known name relates directly to the past industrial heritage of the hill, as its summit is made of mining waste that is now stabilised and grassed over.  The uppermost part of the summit is relatively small in area and squat in shape, and resembles a pimple as it sits upon another elevated part of the hill.

The hill is situated in the eastern part of the Moel y Gamelin range of hills, and is positioned above the small community of Pentre Bychan which is adjacent to the larger community of Rhosllanerchrugog.

The hill can be accessed from its west where a public footpath traverses the course of the valley where its bwlch is positioned.  However, permission should be sought for those wishing to visit as the summit is not on designated open access land.  When I visited I asked permission to do so and was kindly directed to the best ascent route.

Prior to the survey with the Trimble GeoXH 6000 this hill was not classified but its summit position was indicated to be at SJ 30075 47320, this is where a 154m spot height appears on Ordnance Survey 1:25,000 Explorer maps, with a 23m difference in height compared to the  131m summit spot height on the Ordnance Survey 1:50,000 Landranger map.   The latter spot height is positioned in a field which had been ploughed and probably seeded when I visited.  However there is also high ground to the south-west of where the 154m spot height appears on the ground and each respective point was surveyed, with the following results:

                                                                                                                                 

South-western high point (The Pimple):  153.5m (converted to OSGM15) at SJ 29984 47262

North-eastern high point (154m spot height in field):  153.1m (converted to OSGM15) at SJ 30071 47279

The 153.5m (converted to OSGM15) summit height is not a dramatic height revision when compared to the 154m spot height, but the new summit position does not possess any ring contours on current Ordnance Survey maps and therefore meets 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 surveyed height produced by the Trimble GeoXH 6000, 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 for detailing these revisions.

Although this hill’s new summit height of 153.5m (converted to OSGM15) is only 0.5m different from the spot height that appears on the Ordnance Survey 1:25,000 Explorer map, the hill’s summit position has now been established and this is 8.5m higher than the 145m uppermost contour ring shown on the 1:25,000 map for where the summit of the hill is positioned.

The full details for the hill are:

Cardinal Hill:  Moel y Gamelin

Summit Height (New Height):  153.5m (converted to OSGM15)

Name:  The Pimple

OS 1:50,000 map:  117

Summit Grid Reference:  SJ 29984 47262 

         

Drop:  25.2m (converted to OSGM15)

Gathering data at the summit of The Pimple which resulted in this hill's significant height revision

For details on the survey that significantly revised the summit height of this hill

Myrddyn Phillips (November 2015)

Mapping Mountains – Summit Relocations – 100m Twmpau

The Pimple (SJ 299 472)

There has been a Summit Relocation to the list of the 100m Twmpau (thirty welsh metre prominences and upward) initiated by a survey with the Trimble GeoXH 6000, with the following details being retrospective as the survey that resulted in this summit relocation was conducted on the 20^th October 2015.

Accompanying the main P30 list is a sub list entitled the 100m Sub-Twmpau that takes in all Welsh hills at or over 100m and below 200m in height that have 20m or more and below 30m of drop.  It is this sub category that this hill in now included in, as prior to the survey with the Trimble GeoXH 6000 it had not been listed in the sub list adjoined to the original P30 lists on Geoff Crowder’s v-g.me website.

The survey was conducted in the eastern part of the Bryniau Clwyd range of hills, above the small community of Pentre Bychan which is adjacent to the larger community of Rhosllanerchrugog, and the hill can be accessed from its west where a public footpath traverses the course of the valley where its bwlch is positioned.  However, permission should be sought for those wishing to visit as the summit is not on open access land.  When I visited I asked permission to do so and was kindly directed to the best ascent route.

The name of the hill is The Pimple; this is a locally known name that was given me when I made enquiries during the survey for its bwlch position.  The hill remains unnamed on current Ordnance Survey maps and its locally known name relates directly to the past industrial heritage of the hill, as its summit is made of mining waste that is now stabilised and grassed over.  The uppermost part of the summit is relatively small in area and squat in shape, and hence its name, as it resembles a pimple as it sits upon another elevated part of the hill.

Although prior to the survey with the Trimble GeoXH 6000 the hill was not classified, its summit position was indicated to be at SJ 30075 47320, this is where a 154m spot height appears on current Ordnance Survey maps.   This spot height is positioned in a field which when I visited, had been ploughed and probably seeded.  However there is also high ground to the south-west of where the 154m spot height appears on the ground and each respective high point was surveyed, with the following results:

South-western high point (The Pimple):  153.5m (converted to OSGM15) at SJ 29984 47262

North-eastern high point (154m spot height in field):  153.1m (converted to OSGM15) at SJ 30071 47279

Therefore the position of the relocated summit is at SJ 29984 47262 and is the top of a relatively small and squat mound made of old mining spoil that is now stabilised and grassed over.  This position is not given a spot height on current Ordnance Survey maps but the Trimble result gave it as 0.4m higher when compared to the position where the 154m spot height appears on the ground and approximately 115 metres south-westward from it.

 

The full details for the hill are:

Cardinal Hill:  Moel y Gamelin

Summit Height:  153.5m (converted to OSGM15)

Name:  The Pimple

OS 1:50,000 map:  117

Summit Grid Reference (New Position):  SJ 29984 47262

   

Drop:  25.2m (converted to OSGM15)

The Trimble GeoXH 6000 gathering data at the new summit position of The Pimple, with the old position of the summit in the ploughed field in the background of this photograph

For details on the survey that relocated the summit of this hill please click {here}

Myrddyn Phillips (October 2015)

Mapping Mountains – Hill Reclassifications – 100m Twmpau

The Pimple (SJ 299 472) - 100m Sub-Twmpau addition

There has been an addition to the Sub category within the 100m Twmpau (thirty welsh metre prominences and upward) hill list instigated by a survey with the Trimble GeoXH 6000.   The hill is situated next to the small community of Pentre Bychan which is adjacent to Rhosllanerchrugog, in the easterly part of the Bryniau Clwyd.

These details are retrospective as the Trimble GeoXH 6000 survey that resulted in this hill’s inclusion as a 100m Sub- Twmpau was conducted on the 20^th October 2015 on a beautiful autumnal day in good, dry and sunny conditions.

The hill can be accessed from its west where a public footpath traverses the course of the valley where its bwlch is positioned.  However, permission should be sought for those wishing to visit as the summit is not on open access land.  When I visited I asked permission to do so and was kindly directed to the best ascent route.

The hill is named The Pimple and its summit is positioned at SJ 299 472.  This is a locally known name for the hill and was found when I made enquiries during a number of data sets taken at the area of the bwlch.  The hill remains unnamed on current Ordnance Survey maps and its locally known name relates directly to the past industrial heritage of the hill, as its summit is made of mining waste that is now stabilised and grassed over.  The uppermost part of the summit is relatively small in area and squat, and looks like a pimple as it sits upon another elevated part of the hill.

Current mapping does not give this hill any summit ring contours, although the adjacent field does have a 154m map spot height on it, both of these points were surveyed with the summit known as The Pimple being 0.4m higher according to the Trimble data.

The survey with the Trimble GeoXH 6000 resulted in a 153.5m (converted to OSGM15) summit height and a 128.3m (converted to OSGM15) bwlch height, giving this hill 25.2m of drop and confirming its entry in to the 100m Sub-Twmpau ranks.

The full details for the hill are:

Cardinal Hill:  Moel y Gamelin

Summit Height:  153.5m (converted to OSGM15)

Name:  The Pimple

OS 1:50,000 map:  117

Summit Grid Reference:  SJ 29984 47262

Drop:  25.2m (converted to OSGM15)

Gathering data at the summit of The Pimple, which resulted in this hill's confirmation as a 100m Sub-Twmpau

For details on the survey that resulted in this hill being included as a 100m Sub-Twmpau please click {here}

Myrddyn Phillips (October 2015)

Mapping Mountains – Trimble Surveys – Moel y Gamelin

20.10.15  The Pimple (SJ 299 472)  

The summit of The Pimple (SJ 299 472)

My last two walks had explored the remains of land that was once spoil waste from the Bersham and Hafod Colliery’s respectively, and this walk was similar as just to the west of Bonc yr Hafod is another hill whose map details suggest that it was made of mine spoil dug from the ground.  This hill is also of interest as the current Ordnance Survey 1:50,000 and 1:25,000 maps have a 23m height difference for their summit spot heights with the 1:50,000 giving 131m and the 1:25,000 giving 154m, I thought a little Trimbling should be able to sort this out.

I parked on a housing estate at approximately SJ 298 468 which is to the south-west of the summit and walked down the road to a gate / stile giving access to a public footpath in a field, where two horses were contentedly grazing and one sauntered over to make closer inspection of their new visitor.

The critical bwlch for this hill is positioned westward of the summit in a valley that is narrow on the hill to hill traverse and elongated on the valley to valley traverse, without the aid of optical implements I knew that I may have to take a series of data sets to then compare heights, and the first of these was beside a hedgerow where interpolation suggests the bwlch to be placed.

Beyond was a foot stile and cropped grass leading to a house, as I wanted to ask about the name of the hill I headed toward it and Glenys Valentine came out to meet me, Glenys is aged 77 and proved a lovely woman to speak with, within a few minutes her son; Kevin, pulled up and the three of us chatted away for 15 minutes or so, they know the mound at the top of their field as ‘The Pimple’ and although Glenys can speak Welsh and Kevin had a smattering of the language, it was the English term they used and knew the hill by, this had been used by the family for a number of generations.  I also asked if I could survey a number of points close to the house and explained what I was doing.  They both gave me permission to do so and Kevin suggested the best way to take to visit the summit.

Over the next hour I happily gathered a further four data sets from various points on the valley to valley traverse, this was complicated by a mound near to the house and ground either side joining and continuing down valley. 

Gathering data from the critical bwlch of The Pimple

Once I was satisfied that sufficient data sets had been gathered from the area of the bwlch I headed up the hill to the summit of The Pimple, this is as its name suggests; a small mound perched on top of another larger one, all is land that was once mine spoil, it is now grassed over.  As the Trimble gathered data I looked over toward the adjacent field where the 154m spot height appears on current maps, and once the Trimble had done its stuff I clambered over the fence and marched to the top of the ploughed and smoothly rounded field.

Gathering data from the summit of The Pimple

It wasn’t difficult to judge where the summit was placed and the Trimble was soon perched on top of my rucksack gathering its allotted five minutes of data.  Thankfully all was quiet hereabouts as where the summit is situated was just out of sight of many of the surrounding buildings.

Gathering data from the high point in the adjacent field

Once data were gathered I packed the Trimble away and clambered back over the fence, walked down the hill to the grassed valley and back to my car.

Survey Result:

The Pimple (significant name change)

Summit Height:  153.5m (converted to OSGM15) (significant height revision)

Summit Grid Reference:  SJ 29984 47262 (summit relocation confirmed)

Bwlch Height:  128.3m (converted to OSGM15)

Bwlch Grid Reference:  SJ 29752 47350

Drop:  25.2m (100m Sub-Twmpau addition confirmed)

Dominance:  16.44%

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