Monday, 11 September 2017

Mapping Mountains – Summit Relocations – 100m Twmpau


100m Twmpau – Summit Relocations

The 100m Twmpau (thirty welsh metre prominences and upward) are the Welsh hills at or above 100m and below 200m in height that have a minimum drop of 30m.  Accompanying the main P30 list is a sub list entitled the 100m Sub-Twmpau with the qualification to this sub category being all Welsh hills at or above 100m and below 200m in height with 20m or more and below 30m of drop.

The list is authored by Myrddyn Phillips and the posts that have appeared on Mapping Mountains detailing the summit relocations to the main P30 list and the sub list appear below presented chronologically in receding order.








Mapping Mountains - Summit Relocations - 100m Twmpau

Pt. 173.8m (SN 225 503) - 6th summit relocation

Survey post for Pt. 173.8m


There has been a Summit Relocation to the 100m Twmpau (thirty welsh metre prominences and upward) list initiated by a survey with the Trimble GeoXH 6000, with the survey that resulted in this summit relocation being conducted on the 13th May 2016.

The hill is adjoined to the Rhos Ymryson range of hills and is situated to the north-east of Aberteifi (Cardigan) and to the west south-west of Aberporth, with the high point of the hill being close to the small community of Felinwynt which only comprises a few houses, and as the hill does not possess a name of its own on current Ordnance Survey maps, and as I do not know an appropriate name for it either from local enquiry or from historical research it is being listed under the point (Pt. 173.8m) notation.

Access to the hill is relatively easy as it comprises a large grassy field which has a minor lane running over it in a north to south direction.  However, the high point as surveyed with the Trimble GeoXH 6000 is not on open access land and therefore permission to visit should be sought.

The highest spot height adjoined to this hill on Ordnance Survey maps is 174m and this is positioned on the minor lane and adjacent to where a fence heads westward across a field.  A data set was taken with the Trimble from the high point of the road as well as from what was deemed to be the high point of the adjacent field, the results appear below:


High point of road:  173.7m (173.695m, converted to OSGM15)

High point of field:  173.8m (173.811m, converted to OSGM15)


These two results are very close and there is a possibility that higher ground exists in the field when compared to where the Trimble set-up position was placed.  However, for now this Trimble data is the most accurate that is known for this hill, and although the corner of the field is very close to the high point of the road it is worth itemising this positional change as a summit relocation as many people may just dip their toe on the tarmac instead of visiting the land within the adjacent field.

Therefore, the known higher part of the hill as surveyed with the Trimble GeoXH 6000  is not on the minor lane as ground in the adjacent westerly field is approximately 0.12m higher.


The full details for the hill are:

Cardinal Hill:  Rhos Ymryson

Summit Height:  173.8m (converted to OSGM15)

Name:  Pt. 173.8m

OS 1:50,000 map:  145

Summit Grid Reference (New Position):  SN 22587 50306 
  
Drop:  c 55m



The Trimble GeoXH 6000 gathering data at the summit of Pt. 173.8m, with the minor road where the 174m spot height appears on the ground on the other side of the gorse hedgerow in the background of this photograph

For details on the survey that relocated the summit of this hill.

Myrddyn Phillips (May 2016)






Mapping Mountains - Summit Relocations - 100m Twmpau

Pentre Clawdd Gorse (SJ 311 442) - 5th summit relocation

Summit survey post for Pentre Clawdd Gorse

Bwlch survey post for Pentre Clawdd Gorse

Hill Reclassifications post for Pentre Clawdd Gorse  


There has been a Summit Relocation that was initiated by a survey with the Trimble GeoXH 6000 to the list of 100m Twmpau (thirty welsh metre prominences and upward) with the survey that resulted in this summit relocation being conducted on the 23rd February 2016.

The name of the hill is Pentre Clawdd Gorse and it is positioned in the eastern part of the Moel y Gamelin range of hills, and situated to the east of the A 483 and north-east of the town of Rhiwabon (Ruabon).  Access to the hill is relatively easy as its summit is positioned on Wat’s Dyke, this ancient earthwork stretches from the Dee estuary in the north to Shropshire in the south, and public footpaths follow its course over this hill’s broad north – south summit ridge crest.

Pentre Clawdd Gorse is adjoined to the summit of Wynnstay Park which is approximately one kilometre due south from it, with the latter having a 141m spot height given it on Ordnance Survey 1:25,000 Explorer maps.  The summit of Wynnstay Park was surveyed on the 20th October 2015 resulting in a 141.2m (converted to OSGM15) summit height.  On the same day the bwlch positioned at SJ 307 437 was also surveyed resulting in a bwlch height of 111.7m (converted to OSGM15).  If this was the critical bwlch for Wynnstay Park the hill just failed to make P30 Twmpau status with only 29.5m of drop.  However, further map study showed that the summit area of Pentre Clawdd Gorse has two small 140m ring contours on it, and if its summit proved to be at least 0.5m higher than the summit of Wynnstay Park, the bwlch positioned at SJ 307 437 would be adjoined to Pentre Clawdd Gorse and the hill would be a new P30.

As the summit of Pentre Clawdd Gorse was surveyed as 0.8m higher than Wynnstay Park, and as the latter was listed in the Hills to be surveyed sub list that accompanied the original Welsh 100m P30 listings on Geoff Crowder’s v-g.me website, the summit of the qualifying hill has been relocated to that of Pentre Clawdd Gorse.

Therefore the position of the relocated summit is at SJ 31131 44252 and is situated on the highest point of this part of the ancient earthwork known as Wat’s Dyke.  Either side of this earthwork are fields, one given over to grazing and the other which is arable.  This part of Wat’s Dyke has a narrow line of mature trees growing on it which adds perspective and interest to the landscape, although their proximity hampered satellite reception.  This position is not given a spot height on current Ordnance Survey maps and has an uppermost contour ring of 140m, and is approximately 1.4 kilometres northward of the summit of Wynnstay Park.

The full details for the hill are:

Cardinal Hill:  Moel y Gamelin

Summit Height:  142.0m (converted to OSGM15)

Name:  Pentre Clawdd Gorse

OS 1:50,000 map:  117

Summit Grid Reference (New Position):  SJ 31131 44252 
  
Drop:  30.3m (converted to OSGM15)


The Trimble GeoXH 6000 gathering data at the summit of Pentre Clawdd Gorse, with the summit of Wynnstay Park on the left and in the background of this photograph

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

Myrddyn Phillips (February 2016)







Mapping Mountains - Summit Relocations - 100m Twmpau

Wynnstay Park (SJ 309 429) - 4th summit relocation

Survey post for Wynnstay Park


There has been a Summit Relocation for a hill that was originally surveyed for 100m Twmpau (thirty welsh metre prominences and upward) status, and which was initiated by surveying with the Trimble GeoXH 6000, with these details being retrospective as the survey that resulted in this summit relocation was conducted on the 20th October 2015.

The survey was conducted in the eastern part of the Moel y Gamelin range of hills, on the south-eastern outskirts of Rhiwabon (Ruabon), with the hill being situated on the old country estate of the Wynn family; the estate house has now been converted to flats and private houses.  Access to the hill is easy from the north as a paved road leads to its summit.  Parking can either be found adjacent to Broth Lodge at the entrance to the old estate or if wanting a quick visit a car can be driven up the road and parked within 100 metres of the high point of the hill.

The name of the hill is Wynnstay Park and prior to the survey with the Trimble GeoXH 6000 the summit position was listed as SJ 310 430, this is where the 141m spot height appears on the Ordnance Survey 1:25,000 Explorer map.  However, the high point of this hill is south south-westward from where the spot height appears on the ground.

Therefore the position of the relocated summit is at SJ 30990 42931 and is beside a fence next to the remains of a tree root.  The summit is the top of a field that resembles a grass verge as the continuation of the paved road from the estate entrance to the old estate house is only a few metres from it.  This position is not given a spot height on current Ordnance Survey maps and it is approximately 85 metres south south-westward from the previously listed summit position.


The full details for the hill are:

Cardinal Hill:  Moel y Gamelin

Summit Height:  141.2m (converted to OSGM15)

Name:  Wynnstay Park

OS 1:50,000 map:  117

Summit Grid Reference (New Position):  SJ 30990 42931
   
Drop:  c 14m


The Trimble GeoXH 6000 gathering data at the new summit position of Wynnstay Park, with the old position of the summit beyond the gate in the background of this photograph

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

Myrddyn Phillips (October 2015)







Mapping Mountains - Summit Relocations - 100m Twmpau

The Pimple (SJ 299 472) - 3rd summit relocation

Survey post for The Pimple

Hill Reclassifications post for The Pimple

Significant Height Revisions post for The Pimple

Significant Name Changes post for The Pimple


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 20th 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 - Summit Relocations - 100m Twmpau

Cae Boncyn (SJ 238 193) - 2nd summit relocation

Survey post for Cae Boncyn

Significant Name Changes post for Cae Boncyn


There has been a Summit Relocation initiated by a survey with the Trimble GeoXH 6000 to the listing of 100m Twmpau (thirty welsh metre prominences and upward), with the following details being retrospective as the survey that resulted in this summit relocation was conducted on 8th August 2015.

The survey was conducted in the lower hills of the Carnedd Wen range, centred between the small towns of Llansanffraid-ym-Mechain to the hill’s north-west, Llanymynech to the hill’s north-east and Four Crosses to the hill’s south-east, with all three communities being situated beside or close to the Afon Efyrnwy (River Vyrnwy).

The hill was surveyed in the company of Alex Cameron during a multi hill bagging day in lovely sunshine as we visited nine P30 Twmpau hills with seven of them being Trimbled.

The hill is unnamed on current Ordnance Survey maps, having been listed as Bryn y Gelli in the original P30 lists that appeared on Geoff Crowder’s v-g.me website.  This was an invented name partly taken from the farm which is situated just to the south-west of the summit.  However, when we visited the hill we asked Mel Jones at Gelli Farm for permission to do so and also made enquiries concerning the name of the hill, Mel produced a field map of Gelli Farm with the field where the summit of the hill is situated named as Cae Boncyn, unsurprisingly this is also the name that Mel gave us for the highest field.

Prior to the survey with the Trimble GeoXH 6000 the position of the summit was listed as that of its 142m spot height which is situated at SJ 23882 19312.  This spot height is positioned in an adjacent field to where the highest part of the hill is situated, the distance between these two positions is not great but a relocation of a summit to a different field is important and therefore this information warrants a post under the heading of Summit Relocations.

The position of the relocated summit is at SJ 23849 19306 and is the top of a small hillock, hence the Boncyn part of its name, this is not given a spot height on current Ordnance Survey maps but the survey result produced by the Trimble gave it as 142.1m (converted to OSGM15) and approximately 30-40 metres westward from the position of the spot height on Ordnance Survey maps.


The full details for the hill are:

Cardinal Hill:  Carnedd Wen

Summit Height:  142.1m (converted to OSGM15)

Name:  Cae Boncyn

OS 1:50,000 map:  126

Summit Grid Reference (New Position):  SJ 23849 19306
  
Drop:  44m


The Trimble GeoXH 6000 gathering data at the new summit position of Cae Boncyn, with the old position of the summit in the adjacent field beyond the wooden fence in the background of this photo

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

Myrddyn Phillips (August 2015)







Mapping Mountains - Summit Relocations - 100m Twmpau

Gravel Pit Field (SJ 225 167) - 1st summit relocation

Survey post for Gravel Pit Field

Significant Name Changes post for Gravel Pit Field


There has been a Summit Relocation to the listing of 100m Twmpau (thirty welsh metre prominences and upward) hills due to a survey with the Trimble GeoXH 6000, and these details are retrospective as the survey that resulted in this summit relocation was conducted on 8th August 2015.

The survey was conducted in the lower hills of the Carnedd Wen range, between the small communities of Deuddwr and Collfryn, these are situated between the A495 to the west and the A483 to the east.

The hill was surveyed in the company of Alex Cameron during a multi hill bagging day when the sun beat down and we visited nine P30 Twmpau hills with seven of them being Trimbled.

The name of the land where the summit of this hill is situated is Gravel Pit Field and this was derived from the Tithe map, with the hill having been listed as The Mount in the original P30 lists that appeared on Geoff Crowder’s v-g.me website, this was a name taken from the farm which is situated southward of this hill's summit. 

Prior to the survey with the Trimble GeoXH 6000 the position of the summit was listed as that of its triangulation pillar which is submerged in a hedge beside a narrow country lane.  This trig pillar has a 153.951m flush bracket height adjoined to it and is given the rounded up height of 154m on current Ordnance Survey maps, with its flush bracket given the position of SJ 22556 16673 in the OS Trig Database.  However, higher ground exists on the opposite side of the lane in a field.

The position of the relocated summit is at SJ 22598 16703 and is the top of featureless ground a few metres from a hedge in a field, this is not given a spot height on current Ordnance Survey maps but the survey result with the Trimble gave it as 0.99m higher than the flush bracket on the triangulation pillar and approximately 50 metres north-eastward from where it stands in a hedge.


The full details for the hill are:

Cardinal Hill:  Carnedd Wen

Summit Height:  154.9m (converted to OSGM15)

Name:  Gravel Pit Field

OS 1:50,000 map:  126

Summit Grid Reference (New Position):  SJ 22598 16703 

Drop:  c 47m


The Trimble GeoXH 6000 gathering data at the new summit position of Gravel Pit Field, with the old position of the summit opposite the gate in the centre right of this photograph

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

Myrddyn Phillips (August 2015)


No comments: