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

 

Addlebrough (SD 947 878) 

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 Addlebrough (SD 947 878)

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 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 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

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

The name the hill is listed by is Addlebrough, and it is adjoined to the Whernside group of hills, which are situated in the central Pennines, and it is positioned with the A684 road to its north, a minor road to its west and the B6160 road to its south-east, and has the village of Bainbridge towards the north-west.

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 945 881 based on where the contemporary Ordnance Survey 1:25,000 Explorer map indicated an uppermost 480m ring contour to be situated. 

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

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 94m of drop, based on interpolation of what was indicated as its highest 480m contour ring that appears on the Ordnance Survey 1:25,000 Explorer map giving an estimated c 481m summit height, with its listed summit position being relocated to SD 947 878, and the 387m col spot height that appears on 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 summit image of Addlebrough (SD 947 878)

LIDAR analysis gives the highest ground on this hill as 478.9m positioned at SD 94744 87872, and in relation to the originally listed summit position this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies to when the high point is positioned in a different field, to a different feature such as a conifer plantation, within a different map contour, a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is considered 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 summit height produced by LIDAR analysis is 478.9m and this is positioned at SD 94744 87872.  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 300 metres south-eastward from where the original listed summit is positioned.

 

The full details for the hill are:

Group:  Whernside

Name:  Addlebrough

OS 1:50,000 map:  98

Summit Height:  478.9m (LIDAR)

Summit Grid Reference (New Position):  SD 94744 87872 (LIDAR)

Col Height:  386.8m (LIDAR)

Col Grid Reference:  SD 94822 87149 (LIDAR)

Drop:  92.1m (LIDAR)

 

Myrddyn Phillips and Aled Williams (May 2023)