Thursday, 21 June 2018

Mapping Mountains – Significant Height Revisions – Tumps



View Edge (SO 422 809)

There has been a Significant Height Revision to a hill that is listed in the Tumps, which was initiated by a survey with the Trimble GeoXH 6000 which took place on the 4th May 2018 in the company of Bob Kerr, with clear and calm conditions on the hill.

The name of the hill is View Edge and it is situated in Region 38 the Welsh Borders and in Section 38A Shropshire.  The hill is positioned between a number of roads with the B 4367 to its west, the B 4368 to its north and the A 49 to its east, and has the small town of Craven Arms towards its north north-east.

View Edge (SO 422 809)

As the hill is not a part of designated open access land permission to visit should be sought, for those wishing to do so a public footpath from the south accesses the wood close to where the summit is situated.

Prior to the survey with the Trimble GeoXH 6000 this hill was listed with a 321m summit height which is based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map.  Otherwise I have found no other summit height on any scaled Ordnance Survey map, with only the Six-Inch map published in 1903 giving a 1045ft (318.5m) height to the east of the summit.

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

Extract from the Ordnance Survey Six-Inch map published in 1903

The summit of the hill is positioned in mixed woodland which is not ideal for satellite coverage, and because of this a 15 minute data set was taken.  However, once data were processed the standard deviation was 1.0m and the estimated accuracies were 0.5 – 1m: 25.65%.

The 324.1m (converted to OSGM15) summit height produced by the Trimble GeoXH 6000 is 3.1m higher than the previously listed height of 321m, which was based on the summit spot height on contemporary Ordnance Survey 1:25,000 maps, and therefore this new height comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose Ordnance Survey or Harvey map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR, also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR, and also hill’s that do not possess a summit spot height and whose estimated summit height has a 2m or more discrepancy when compared to data produced either by the Trimble or by LIDAR.  As heights on different scaled Ordnance Survey maps are not consistent the height given on the 1:25,000 Explorer map is being prioritised in favour of the 1:50,000 Landranger map for detailing these revisions.

The summit of this hill is easily identified and consists of ground near the base of a tree, which is approximately 20 metres from a fence and an adjacent closely cropped grazing field.  On the day that the survey took place the wood was resplendent with bluebells.

The Trimble GeoXH 6000 gathering data at the summit of View Edge

Therefore this hill’s new summit height is 324.1m (converted to OSGM15), which is 3.1m higher than its previously listed height which was derived from the 321m summit spot height on the Ordnance Survey 1:25,000 Explorer map.


The full details for the hill are:

Group:  Beacon Hill

Summit Height (New Height):  324.1m (converted to OSGM15)

Name:  View Edge

OS 1:50,000 map:  137

Summit Grid Reference:  SO 42278 80988
  
Drop:  c 170m



Myrddyn Phillips (June 2018)








Wednesday, 20 June 2018

Mapping Mountains – Trimble Surveys – Beacon Hill



04.05.18  View Edge (SO 422 809)

View Edge (SO 422 809)

Having visited and surveyed Callow Hill (SO 460 850) Bob and I headed south-west through Craven Arms to the series of narrow country lanes leading toward View Edge.  The hill rose out of pastured green land almost pyramidal in profile with mixed woodland dominating its upper slopes.

Prior to our visit I’d looked at a series of summit photographs and this hill’s high point is immersed in a wood, which didn’t give me much expectation for good satellite coverage for the Trimble.

We parked just off the narrow minor road that heads east over the southern ridge of View Edge adjacent to a small disused lime quarry and walked the short distance toward its upper escarpment. 

The old lime quarry

A series of vehicle tracks led past a number of grassed hummocks toward open fields leading upward toward the wooded summit.

Approaching the summit

The wood proved beautiful and it had to be so as we spent an inordinate amount of time in it, patiently waiting for the Trimble to ever so slowly ebb down to the required 0.1m accuracy level before data should be logged.

Once in the wood it was an easy task to identify the high point which consisted of ground festooned in bluebells under a canopy of deciduous trees whose branches shot up in all directions.

Gathering data at the summit of View Edge

The long wait now started, we chatted about all manner of stuff as I scampered up to check on the Trimble’s accuracy progress, after a 20 minute wait I activated the equipment and we waited a further 15 minutes for it to gather a suitable amount of data that hopefully can result in an adequate data set.

Bob at the summit of View Edge

Once the Trimble was closed down I took a few photographs and we retraced our inward route back down the adjacent field and through the old quarry to Bob’s car; next stop Hopesay and Burrow.



Survey Result:


View Edge

Summit Height:  324.1m (converted to OSGM15) (significant height revision)

Summit Grid Reference:  SO 42278 80988

Drop:  c 170m

Dominance:  52.49%









Tuesday, 19 June 2018

Mapping Mountains – Significant Name Changes – The Fours


Pt. 428m (NY 300 017)

There has been a Significant Name Change to a hill that is listed in The Fours, with this being announced when the 2nd edition of The Fours was published by Mapping Mountains Publications on the 24th April 2018.

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

The Fours – English hills at and above 400m and below 500m in height that have 30m minimum drop.  Accompanying the main list of The Fours are three categories of sub hills, with this hill listed as a 400m Sub-Four.  The criteria for 400m Sub-Four status are all English hills at and above 400m and below 500m in height that have 20m or more and below 30m of drop.

The list is co-authored by Myrddyn Phillips and Aled Williams, with the 1st edition of the list having been published by Europeaklist in December 2013 and by Haroldstreet in January 2014, with the 2nd edition of the list published by Mapping Mountains Publications and by Haroldstreet on the 24th April 2018.

The hill is situated in the Sothern Fells of the Lake District and is placed in Region 34, Section 34D with its Cardinal Hill being The Old Man of Coniston (SD 272 978).  The hill is positioned between the steam valleys of the Greenburn Beck to the north-west and the Pierce How Beck and the Yewdale Beck towards the south-east, and has the small community of Little Langdale towards the north-east.

When the listing that is now known as The Fours was originally compiled this hill was not included as it did not meet the criteria then used, however this list has now been standardised and interpolated height and drop values also added, it was subsequently listed under the name of High Fell in the 1st edition of The Fours when the list was published by Europeaklist in December 2013. 

Prior to publication of the 2nd edition of The Fours enquiries were made with two well-known Lake District guide book authors, resulting in a non-committal reply in regard to the name of High Fell, and the advice that ‘one would need to talk to genuine locals and shepherds to give definitive answers’. 

Extract from the Ordnance Survey series of Six-Inch maps

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

Therefore, the name this hill is now listed by in The Fours is Pt. 428m and this follows the standard practice of using the point notation for hill’s whose name has not been substantiated by the authors either through local enquiry, contemporary maps or from historical documentation. 


The full details for the hill are:

Group:  The Old Man of Coniston

Name:  Pt. 428m

Previously Listed Name:  High Fell 

Summit Height:  428m

OS 1:50,000 map:  90

Summit Grid Reference:  NY 30023 01704 
 
Drop:  c 20m


Myrddyn Phillips and Aled Williams (June 2018)






Monday, 18 June 2018

Mapping Mountains – Hill Reclassifications – 200m Twmpau


Pt. 252.3m (SH 697 167) – 200m Sub-Twmpau addition

There has been an addition to the 200m Twmpau list due to LIDAR analysis conducted by Myrddyn Phillips, with the criteria for this list being:

200m Twmpau - Welsh hills at and above 200m and below 300m in height with 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau with the criteria for this sub category being all Welsh hills at and above 200m and below 300m in height with 20m and more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

Prior to LIDAR analysis this hill was listed with c 19m of drop based on the 252m summit spot height that appears on the Ordnance Survey Interactive Coverage Map hosted on the Geograph website and an estimated bwlch height of c 233m based on bwlch contouring between 230m – 240m.

Extract from the Ordnance Survey Interactive Coverage Map hosted on the Geograph website

As the name of the ffridd taking in this hill’s summit has not been confirmed the hill is being listed by the point (Pt. 252.3m) notation and it is adjoined to the Cadair Idris group of hills, which are situated in the south-western part of North Wales (Region A, Sub-Region A3), and the hill is positioned with the A 493 road to its north and has the town of Dolgellau towards its east north-east.

As the hill is a part of designated open access land the summit can be approached from a number of directions, with a bridleway to the south of the hill probably giving easiest access.

The addition of this hill to 200m Sub-Twmpau status is due to LIDAR analysis conducted by Myrddyn Phillips.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

The 1m DTM LIDAR analysis gives the hill the following details:


Name:  Pt. 252.3m

Summit Height:  252.3m

Summit Grid Reference:  SH 69722 16736

Bwlch Height:  232.05m

Bwlch Grid Reference:  SH 69739 16620 & SH 69730 16624 & SH 69732 16628

Drop:  20.2m

LIDAR image of Pt. 252.3m

Therefore, the 252.3m LIDAR analysis for the summit position at SH 69722 16736 and the 232.05m LIDAR analysis for the bwlch position at SH 69739 16620 and SH 69730 16624 and SH 69732 16628 gives this hill 20.2m of drop, which confirms its addition to 200m Sub-Twmpau status.


The full details for the hill are:

Group:  Cadair Idris

Name:  Pt. 252.3m

OS 1:50,000 map:  124

Summit Height:  252.3m (LIDAR)

Summit Grid Reference:  SH 69722 16736 (LIDAR)

Bwlch Height:  232.05m (LIDAR)

Bwlch Grid Reference:  SH 69739 16620 & SH 69730 16624 & SH 69732 16628 (LIDAR)

Drop:  20.2m (LIDAR)


Myrddyn Phillips (June 2018)




Sunday, 17 June 2018

Mapping Mountains – Summit Relocations – The Fours


High Hill (SD 833 636)

There has been a Summit Relocation to a hill that is listed in The Fours initiated by LIDAR analysis conducted by Myrddyn Phillips.  The Fours is the title for the list of 400m hills of England and is co-authored by Myrddyn Phillips and Aled Williams with the 2nd edition of the booklet containing this list published by Mapping Mountains Publications on the 24th April 2018.

The criteria for the list that this summit relocation affects are:

English hills at and above 400m and below 500m in height that have 30m minimum drop, accompanying the main list of The Fours are three categories of sub hills, with this hill being classified in the 390m Sub-Fours.  The criteria for 390m Sub-Four status are all English hills at and above 390m and below 400m in height that have 30m minimum drop. 

The name of the hill is High Hill and it is situated in Region 35; The Northern and Central Pennines, Section 35B; The Central Pennines, and is positioned with the B 6480 road to its west which joins the A 65 road to its south south-west, and has the small town of Settle to its west.

As the upper section of the hill is a part of designated open access land an ascent is feasible from most directions, with a public footpath heading west to east and placed to the north of the summit and relatively easy access from a minor road to the south.

The summit area of this hill has a 390m uppermost contour that is given a 398m spot height positioned at SD 83244 63492 on contemporary Ordnance Survey maps, and this is where the summit of the hill was listed in the 1st edition of The Fours when published by Europeaklist in December 2013.

Extract from the Ordnance Survey Interactive Coverage Map hosted on the Geograph website with the summit position circled

The highest land in the 390m ring contour was analysed via LIDAR by Myrddyn Phillips.  The LIDAR (Light Detection & Ranging) technique is highly accurate height data that is now freely available for much of England and Wales. 

The summit height produced by LIDAR analysis is 398.3m and is positioned at SD 83338 63674, this position is not given a spot height on contemporary Ordnance Survey maps, although it and that of the previously listed summit both possess an uppermost 395m ring contour on OS Maps.

LIDAR image of the summit area of High Hill

Therefore, the confirmation of the relocated summit position is at SD 83338 63674 and this is approximately 200 metres north north-east from where the previous listed 398m map heighted summit was given in the 1st edition of The Fours.


The full details for the hill are:

Cardinal Hill:  Pen y Ghent

Summit Height:  398.3m (LIDAR)

Name:  High Hill

OS 1:50,000 map:  98

Summit Grid Reference (New Position):  SD 83338 63674 (LIDAR)  

Drop:  40.2m (LIDAR)


Myrddyn Phillips and Aled Williams (June 2018)
















Saturday, 16 June 2018

Mapping Mountains – Significant Height Revisions – Tumps



Callow Hill (SO 460 850)

There has been a Significant Height Revision to a hill that is listed in the Tumps, which was initiated by a survey with the Trimble GeoXH 6000 which took place on the 4th May 2018 in the company of Bob Kerr, with clear and calm conditions on the hill.

The name of the hill is Callow Hill and it is situated in Region 38 the Welsh Borders and in Section 38A Shropshire.  The hill is positioned between the A 49 road to its north-west and the B 4368 road to its south-east, and has the small town of Craven Arms towards its south-west.

The summit of the hill and its upper north-eastern section comprises mixed woodland which is a part of designated open access land, with public footpaths accessing this land from the north-west and the east.

Callow Hill (SO 460 850) with the Flounders' Folly on top

Prior to the survey with the Trimble GeoXH 6000 this hill was listed with a 336m summit height which is based either on interpolation from the uppermost 335m contour ring on contemporary Ordnance Survey 1:25,000 Explorer maps, or it is based on a 336m spot height that appears on maps such as the one shown below.  The Ordnance Survey series of Six-Inch maps also show heights that are higher than the 336m listed height; two examples are also given below.

336m spot height on Callow Hill

Extract from the Ordnance Survey Six-Inch map published in 1903

Extract from the Ordnance Survey Six-Inch map published in 1953

This hill has a 24m (80ft) high stone tower near its high point that is known as the Flounders’ Folly, and two data sets were taken from land close to the base of this structure, with the first approximately 30 metres from the tower and the second approximately seven metres from its base, the land at the first survey was given as higher by the Trimble GeoXH 6000 survey, with the caveat that the highest land on the hill was judged visually to be on a small raised earthen embankment that is a part of a boundary hedge, as this was considered a relatively recent man-made boundary it was judged not to be a natural part of the hill.

The 339.1m (converted to OSGM15) summit height produced by the Trimble GeoXH 6000 is 3.1m higher than the previously listed height of 336m, which was based either on interpolation or on a spot height, and therefore this new height comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose Ordnance Survey or Harvey map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR, also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR, and also hill’s that do not possess a summit spot height and whose estimated summit height has a 2m or more discrepancy when compared to data produced either by the Trimble or by LIDAR.  As heights on different scaled Ordnance Survey maps are not consistent the height given on the 1:25,000 Explorer map is being prioritised in favour of the 1:50,000 Landranger map for detailing these revisions.

The summit of this hill is easily identified and consists of grass beside the narrow path that follows the summit ridge in a north-eastward direction from the stone tower, with the caveat that ground in a boundary hedge was visually higher but judged to be man-made.

The Trimble GeoXH 6000 gathering data at the summit of Callow Hill

Therefore this hill’s new summit height is 339.1m (converted to OSGM15), which is 3.1m higher than its previously listed height which came from interpolation or a spot height.


The full details for the hill are:

Group:  Stiperstones

Summit Height (New Height):  339.1m (converted to OSGM15)

Name:  Callow Hill

OS 1:50,000 map:  137, 138

Summit Grid Reference:  SO 46075 85060
  
Drop:  157.0m (Trimble summit and LIDAR col)



Myrddyn Phillips (June 2018)



Friday, 15 June 2018

Mapping Mountains – Significant Name Changes – Y Trichant


Gwernaffel (SO 259 712)

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 survey which took place on the 19th April 2018.

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

Y Trichant – Welsh hills at and above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub category entitled the Sub-Trichant consisting of all Welsh hills at and above 300m and below 400m in height that have 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips and the Introduction to the list and the re-naming and publication history was published on Mapping Mountains on the 13th May 2017.

The hill is adjoined to the Beacon Hill range of hills, which are situated in the north-eastern part of Mid and West Wales (Region B, Sub-Region B1), and is positioned with the A488 road to its south and has the small town of Tref-y-clawdd (Knighton) towards its east north-east.

The hill appeared in the 300m P30 list on Geoff Crowder’s v-g.me website under the partly invented name of Moel Gilla, with an accompanying note stating; Name from cwm & wood to the North.  


Moel Gilla
   380c
   SO259712
   137/148
201
   Name from cwm & wood to the North.


During my early hill listing I thought it appropriate to either invent a name for a hill, or use a name that appeared near to the summit of the hill on Ordnance Survey maps of the day.  My preference was to use farm names and put Pen, Bryn or Moel in front of them or as in this instance, use the name of a cwm and wood and prefix this with the word Moel.  This is not a practice that I now advocate as with time and inclination place-name data can be improved either by asking local people or by examining historical documents, through this form of research an appropriate name for the hill can usually be found.

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

When visiting this and adjacent hills I was fortunate to speak with a number of local farmers including John and Liz Roberts of the Racecourse Farm (SO 267 732), who I met at the summit of Waun Sidan (SO 250 726), it was an easy task to point to this hill across the intervening Cwm Gilla and ask its name, John told me it is known as Gwernaffel after the estate house of the same name which is situated at SO 267 706 and which has association with Sir Robert Green Price. 

John and Liz Roberts of the Racecourse Farm

Therefore, the name this hill is now listed by in the Y Trichant is Gwernaffel, and this was derived from local enquiry.


The full details for the hill are:

Group:  Beacon Hill

Name:  Gwernaffel

Previously Listed Name:  Moel Gilla

Summit Height:  380.4m (converted to OSGM15)

OS 1:50,000 map:  137, 148

Summit Grid Reference:  SO 25947 71212

Drop:  34.3m (converted to OSGM15)



Myrddyn Phillips (June 2018)