Mapping Mountains – Summit Relocations – The Fours – The 400m Hills of England

Rushy Knowe (NY 681 820)

There has been a Summit Relocation to a hill that is listed in the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill derived from detail on contemporary maps produced from Ordnance Survey data.

This was initiated by Joe Nuttall who produced a summit analysis programme that used LIDAR with an alternative height map (DEM) allowing identification of summits and cols and thereby drops.  The resulting spreadsheet that Joe produced contains over 29600 hills.

This spreadsheet is being evaluated by a number of people, including Ronnie Bowron, who passed the details of this hill for evaluation.

The criteria for the list that this summit relocation applies to are:

The Fours – The 400m Hills of England.  English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main listing of The Fours are three categories of sub hills, with this hill being listed in the 390m Double Sub-Four category, the criteria for which are all English hills at or above 390m and below 400m in height that have 20m or more and below 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and the 2nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Rushy Knowe, and it is adjoined to Sighty Crag group of hills, which are situated in the north-eastern part of England (Region 33 Scottish Border to the River Tyne), and it is positioned with a minor road and Kielder Water to its north, and has the village of Bellingham towards the east.

When the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, this hill was listed with an estimated c 28m of drop, based on the 397m summit spot height positioned at NY 677 817 and an estimated c 369m col height based on interpolation of 10m contouring between 360m – 370m that appear on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map.

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

The details for this hill have now been re-assessed against Ordnance Survey data hosted on the Magic Maps website, and this mapping gives a 398m spot height on the summit area of this hill positioned at NY 681 820.

Extract from the Magic Maps website

This new summit position and interpolation of col contouring were also re-assessed against the OS Maps website.  This is the replacement for OS Get-a-map and has contours at 5m intervals which are proving consistently more accurate compared to the 5m contours that sometimes appear on Ordnance Survey 1:25,000 Explorer maps and used to appear on the online Vector Map Local.  This re-assessment resulted in the estimated col height for this hill being amended to c 371m, with this based on interpolation of 5m contouring between 370m – 375m.

Extract from the OS Maps website

The above detail comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the hill’s high point is in a different field, or where a number of potential summit positions are within close proximity and the highest point is not where previously given, or when it is positioned to a different feature such as in a conifer plantation, or when the high point of the hill is placed within a different map contour, or when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary that is judged to be a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist.

 

Therefore, the listed summit height of this hill is now 398m and its new position is NY 68108 82036, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and is approximately 350 metres north-eastward from where the previously listed summit is positioned.

The full details for the hill are:

Group:  Sighty Crag

Name:  Rushy Knowe

OS 1:50,000 map:  80

Summit Height:  398m (spot height)

Summit Grid Reference (new position):  NY 68108 82036 (spot height)

Col Height:  c 371m (interpolation)

Col Grid Reference:  NY 67304 81373 (interpolation)

Drop:  c 27m (spot height summit and interpolated col)

Myrddyn Phillips and Aled Williams (August 2020)