Thursday, 16 November 2017

Mapping Mountains – Significant Height Revisions – Tumps


Tumps – Significant Height Revisions


The Tumps (thirty & upward metre prominences) are all hills in Britain that have a minimum drop of 30m, irrespective of their height.  The list was collated by Mark Jackson and was reliant upon the duplication of many other lists that already existed such as the accumulated listings of the Simms, Deweys, Donald Deweys, Highland Fives, Y Pedwarau, The Fours and Y Trichant, and the posts that have appeared on Mapping Mountains detailing the significant height revisions specifically for this list appear below presented chronologically in receding order.









Mapping Mountains - Significant Height Revisions - Tumps

View Edge (SO 422 809) - 6th significant height revision

Survey post for View Edge


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)






Mapping Mountains - Significant Height Revisions - Tumps

Callow Hill (SO 460 850) - 5th significant height revision

Survey post for Callow Hill


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)






Mapping Mountains - Significant Height Revisions - Tumps

Wapley Hill (SO 347 624) - 4th significant height revision

Survey post for Wapley Hill


There has been a Significant Height Revision to a hill that is listed in the Tumps.  This height revision was initiated be a survey with the Trimble GeoXH 6000 which took place on the 15th February 2018 in good conditions with clear visibility, albeit quite chilly.

The name of the hill is Wapley Hill and it is situated in Region 38 the Welsh Borders and in Section 38B West Gloucestershire, Hereford and Worcester.  The hill is positioned above the B 4362 road which is to its north, and has the town of Llanandras (Presteigne) towards its north-west and the village of Shobdon towards its east.

Wapley Hill (SO 347 624)

All of the upper part of the hill except for its northern section is a part of designated open access land, and although much of this upper section is forested there are a series of way-marked footpaths leading to its summit, which comprises an impressive Iron Age hill fort.

Prior to the survey with the Trimble GeoXH 6000 this hill was listed with a 329m summit height based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map.  The high point of the hill positioned on one of the ancient embankments that form a series of five defences, this embankment has a modern constructed entrance carved through it, and either side of this, to its immediate north, and its immediate south, are high points, each vying for the accolade of this hill’s summit position, with the northern one having been Abney levelled by numerous people as being slightly higher.

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

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


These two high points were surveyed with the Trimble GeoXH 6000, the results are:

Northerly high point:  332.668m (converted to OSGM15) at SO 34754 62456

Southerly high point:  332.774m (converted to OSGM15) at SO 34749 62440 

The Trimble GeoXH 6000 gathering data at the northerly high point of Wapley Hill

The Trimble GeoXH 6000 gathering data at the southerly high point of Wapley Hill

The 332.8m (converted to OSGM15) summit height produced by the Trimble GeoXH 6000 is 3.8m higher than the previously listed height of 329m, which was based on the Ordnance Survey spot height that appears on the 1:25,000 Explorer map and which is positioned on the downward slope of the summit embankment, 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 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.  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 southerly summit of this hill is easily identified and consists of grass on the path that follows the higher of the embankments that form this ancient hill fort, it has steep ground either side of it, whilst the northerly summit is positioned near the base of a small oak tree and which is beside the narrow path that follows the continuation of the same higher embankment.

Therefore this hill’s new summit height is 332.8m (converted to OSGM15), which is 3.8m higher than its previously listed height which came from the 329m spot height on contemporary Ordnance Survey 1:25,000 Explorer maps.


The full details for the hill are:

Group:  Fforest Glud

Summit Height (New Height):  332.8m (converted to OSGM15)

Name:  Wapley Hill

OS 1:50,000 map:  137, 148, 149

Summit Grid Reference:  SO 34749 62440
  
Drop:  160.2m (Trimble summit and LIDAR col)



Myrddyn Phillips (March 2018)





Mapping Mountains - Significant Height Revisions - Tumps

Seager Hill (SO 613 389) - 3rd significant height revision

Survey post for Seager Hill


There has been a Significant Height Revision when compared to data on contemporary Ordnance Survey 1:25,000 Explorer maps to a hill whose highest summit has been under debate for a number of years and that is listed in the Tumps.  This height revision was initiated be a survey with the Trimble GeoXH 6000 which took place on the 30th January 2018 in good conditions with clear visibility.

The name of the hill is Seager Hill and it is situated in Region 38 the Welsh Borders and in Section 38B West Gloucestershire, Hereford and Worcester.  The hill is positioned with the A 438 road to its north-east, and has the small community of Tarrington towards its north and Checkley towards its west south-west.

Seager Hill (SO 613 389)

As the summit of the hill is not a part of designated open access land permission to visit should be sought, for those wishing to do so a track designated a bridleway ascends to a large barn to the south-east of the summit with a public footpath then heading north to crest the ridge between this hill and its south-eastern counterpart, the continuation of this public footpath can also be ascended from the south through a wood.  The continuation toward this hill’s summit from where the footpath crests the ridge is on a green vehicle track and forest track that can be followed to the high point of the hill.

Prior to the survey with the Trimble GeoXH 6000 this hill was noted with a 272m summit height based on an 892ft (271.9m) levelled height that appears on the Ordnance Survey 1:10,560 and 1:2,500 map.

The 271.7m (converted to OSGM15) summit height produced by the Trimble GeoXH 6000 is not a dramatic difference from this hill’s current noted height, and in itself does not come within the parameters used within this page heading, however these parameters prioritise numerical data from Ordnance Survey 1:25,000 Explorer maps, and because of this it does come within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any 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.  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.

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

Therefore, this hill’s new summit height is 271.7m (converted to OSGM15) which is 2.7m higher than the 269m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map.


The full details for the hill are:

Cardinal Hill:  Seager Hill

Summit Height (New Height):  271.7m (converted to OSGM15)

Name:  Seager Hill

OS 1:50,000 map:  149

Summit Grid Reference:  SO 61360 38941  

Drop:  c 167m


Gathering data with the Trimble GeoXH 6000 at the summit of Seager Hill which resulted in this hill's significant height revision


Myrddyn Phillips (March 2018)






Mapping Mountains - Significant Height Revisions - Tumps

Seager Hill South Top (SO 624 379) - 2nd significant height revision

Survey post for Seager Hill South Top


There has been a Significant Height Revision when compared to data on contemporary Ordnance Survey 1:25,000 Explorer maps to a hill whose highest summit has been under debate for a number of years, and although the lower of the two summits is not currently classified within any listing to English hills, the higher summit is listed, with one of its classifications being a Tump.  This height revision was initiated be a survey with the Trimble GeoXH 6000 which took place on the 30th January 2018 in good conditions with clear visibility.

The name of the hill is Seager Hill South Top and it is situated in Region 38 the Welsh Borders and in Section 38B West Gloucestershire, Hereford and Worcester.  The hill is positioned with the A 438 road to its north-east and has a number of narrow lanes to its north north-east, east and south, and has the small community of Woolhope Cockshoot to its south-east and Putley towards its east.

As the summit of the hill is not a part of designated open access land permission to visit should be sought, for those wishing to do so a track designated a bridleway ascends to a large barn to the north of the summit with a public footpath then heading north to crest the ridge between this hill and its north-western counterpart, the continuation of this public footpath can also be ascended from the south through a wood, it is only a short walk from where this footpath crests the ridge to the high point of this hill.

Prior to the survey with the Trimble GeoXH 6000 this hill was noted with a 270m summit height based on an 886ft (270.1m) levelled height that appears on the series of Ordnance Survey Six-Inch maps.

Extract from the series of Ordnance Survey Six-Inch maps

The 271.5m (converted to OSGM15) summit height produced by the Trimble GeoXH 6000 is not a dramatic increase from this hill’s current noted height, and in itself does not come within the parameters used within this page heading, however these parameters prioritise numerical data from Ordnance Survey 1:25,000 Explorer maps, and because of this it does come within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any 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.  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.

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

Therefore, this hill’s new summit height is 271.5m (converted to OSGM15) which is 2.5m higher than the 269m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map.


The full details for the hill are:

Cardinal Hill:  Seager Hill

Summit Height (New Height):  271.5m (converted to OSGM15)

Name:  Seager Hill South Top

OS 1:50,000 map:  149

Summit Grid Reference:  SO 62418 37928
  
Drop:  21m


Gathering data with the Trimble GeoXH 6000 at the summit of Seager Hill South Top which resulted in this hill's significant height revision


Myrddyn Phillips (March 2018)






Mapping Mountains - Significant Height Revisions - Tumps

Caus Castle (SJ 337 077) - 1st significant height revision

Survey post for Caus Castle

Summit Relocations post for Caus Castle


There has been a Significant Height Revision to a hill listed in the Tumps which was initiated by a survey with the Trimble GeoXH 6000, with these details being retrospective as the survey that resulted in this height revision was conducted on the 21st April 2015.

The name of the hill is Caus Castle and the hill is situated in a part of the Shropshire hills that are adjoined to the Cefn Digoll range, with the survey conducted on a sunny and warm day in April in the company of Charlie Leventon, who had suggested the walk.

Although the hill can be easily accessed from the south south-west, permission to do so should be sought as the summit is situated on private land.  When we visited Charlie had received permission for us to do so.

Prior to the survey with the Trimble GeoXH 6000 the hill was listed in the Tumps with a 223m summit height and a 181m col height, with these values giving the hill a drop of 42m.  This summit height is based on the 223m spot height that appears at SJ 33772 07836 on the Ordnance Survey 1:25,000 Explorer map and the Ordnance Survey enlarged mapping hosted on the Geograph website.  However, higher ground exists to the south-west of where this spot height position is situated on the ground.

The summit height of Caus Castle has been increased from its current Ordnance Survey map height, with the result from the Trimble GeoXH 6000 survey giving the height of this hill’s summit as 233.6m (converted to OSGM15).

Therefore this hill’s new summit height is 233.6m (converted to OSGM15) which is 10.6m higher than its previously listed height which came from the 223m spot height on current Ordnance Survey 1:25,000 Explorer maps.


The full details for the hill are:

Cardinal Hill:  Cefn Digoll

Summit Height (New Height):  233.6m (converted to OSGM15)

Name:  Caus Castle

OS 1:50,000 map:  126

Summit Grid Reference:  SJ 33713 07782
  
Drop:  53.2m (converted to OSGM15)


Gathering data from the summit of Caus Castle which resulted in this hill's significant height revision


Myrddyn Phillips (September 2015)


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