Sunday, 2 July 2023

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


Cartridge Hill (SD 671 199) 

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 LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Cartridge Hill (SD 671 199)

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

The FoursThe 400m Hills of England.  English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list are three categories of sub hills; the 400m Sub-Four category, the 390m Sub-Four category and the 390m Double Sub-Four category.  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 Cartridge Hill, and it is adjoined to the Cowpe Moss group of hills, which are situated in the southern Pennines, and it is positioned with a minor road to its west and the A675 road farther to its west, and the A666 road to its east, and has the town of Darwen towards the north-east.

When the original list that later became known as The Fours – The 400m Hills of England was first compiled, the summit position of this hill was given as SD 671 199 based on the position of the 402m spot height that appears on the contemporary Ordnance Survey 1:25,000 Explorer map.  This is also the position the summit of this hill was listed as when the 1st edition of the The Fours was published by Europeaklist in December 2013 and 2nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018. 

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

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

LIDAR analysis gives the highest ground on this hill as 401.841m positioned at SD 67133 19913.  However, this is a part of a raised field boundary and protocols dictate that as this is deemed a relatively recent man-made construct such ground is discounted from the height of a hill. 

LIDAR summit image of Cartridge Hill (SD 671 199)

The height produced by LIDAR analysis to the natural summit of this hill is 401.817m and is positioned at SD 67124 19909 and SD 67125 19910, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the high point of the hill is found to be positioned; in a different field, to a different feature such as in a conifer plantation,  within a different map contour, to a different point where a number of potential summit positions are within close proximity, 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 or covered reservoir 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 height produced by LIDAR analysis to the natural summit of this hill is 401.8m and is positioned at SD 67124 19909 and SD 67125 19910, this position is close to where the 402m summit spot height appears on the contemporary Ordnance Survey 1:25,000 Explorer map, and is approximately 10 metres west south-westward from where the high point of the raised field boundary is positioned. 

 

The full details for the hill are:

Group:  Cowpe Moss

Name:  Cartridge Hill

OS 1:50,000 map:  109

Summit Height:  401.8m (LIDAR)

Summit Grid Reference (New Position):  SD 67124 19909 & SD 67125 19910 (LIDAR)

Col Height:  290.6m (LIDAR)

Col Grid Reference:  SD 66398 19264 (LIDAR)

Drop:  111.2m (LIDAR)

 

Myrddyn Phillips and Aled Williams (July 2023)

 

  

No comments:

Post a Comment