Mapping Mountains – Hill Reclassifications – The Fours - The 400m Hills of England

Wansfell Pike (NY 394 041) – 400m Sub-Four reclassified to Four

There has been a reclassification to the listing of 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 by Ordnance Survey data, coupled with information in the OS Trig Database and LIDAR summit analysis.  With the reclassification subsequently confirmed by a Leica GS15 survey conducted by John Barnard, Jim Bloomer and Graham Jackson and now full LIDAR coverage conducted by Myrddyn Phillips.

LIDAR image of Wansfell Pike (NY 394 041)

The criteria for the list that this reclassification 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, with this hill reclassified from the 400m Sub-Four category, the criteria for which are all English hills at or 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 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 Wansfell Pike, and it is adjoined to the High Street group of hills which are situated in the eastern fells of the Lake District, and it is positioned with the A591 road to its west and the A592 road to its east, and has the town of Ambleside towards the west.

Prior to analysis of data of the interactive mapping hosted on the OS Maps website this hill was listed with an estimated c 26m of drop, based on an estimated c 483m summit height ascertained from an optical survey taken from the summit area of Baystones (486.9m at NY 40312 05143) which concluded that Wansfell Pike is at least 4m lower, and an estimated c 457m col height based on 10m contouring between 450m – 460m that appear on the Ordnance Survey 1:25,000 Explorer map.

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

The reclassification of this hill is due to the analysis of data on the OS Maps website, coupled with information in the OS Trig Database and LIDAR summit analysis.  One of the resources recently available online is the mapping on the OS Maps website, this is the replacement for OS Get-a-map and until recent times had contours at 5m intervals which were proving consistently more accurate compared to the 5m contours that sometimes appear on the Ordnance Survey 1:25,000 Explorer map and used to appear on the online Vector Map Local.  This mapping had col contouring between 450m – 455m, with interpolation placing the height of the col as an estimated c 453 - c 454.

The OS Trig Database records the position of a buried block at the summit of this hill with a height of 483.717m, with initial LIDAR summit analysis giving a height of 483.7m, and when coupled with the estimated col height these values gave this hill an estimated c 30m of drop.

 

Extract from the OS Maps website

However, it was not until the Leica GS15 survey that the details for this hill could be accurately re-assessed.  This confirmed the reclassification of this hill and subsequent analysis of full LIDAR coverage has done likewise.

LIDAR summit image of Wansfell Pike

LIDAR col image of Wansfell Pike

Therefore, the confirmation of the reclassification of this hill from 400m Sub-Four status is due to a Leica GS15 survey, resulting in a 484.3m summit height and a 453.5m col height, with these values giving this hill 30.8m of drop, which is sufficient for it to be classified as a Four.

The full details for the hill are:

Group:  High Street

Name:  Wansfell Pike

OS 1:50,000 map:  90

Summit Height:  484.3m (Leica GS15)

Summit Grid Reference:  NY 39415 04170 (Leica GS15)

Col Height:  453.5m (Leica GS15)

Col Grid Reference:  NY 40045 04658 (Leica GS15)

Drop:  30.8m (Leica GS15)

For the additions, deletions and reclassifications to The Fours -The 400m Hills of England reported on Mapping Mountains since the December 2013 publication of the list by Europeaklist please consult the following Change Registers:

The Fours

The Fours – 400m Sub-Four

The Fours – 390m Sub-Four

The Fours – 390m Double Sub-Four

Myrddyn Phillips and Aled Williams (July 2018)