Wednesday, 14 June 2017

Mapping Mountains - Hill Reclassifications - The 500-Metre Tops of Ireland



The 500-Metre Tops of Ireland – Hill Reclassifications

The 500-Metre Tops of Ireland are the Irish hills at or above 500m and below 609.6m (2,000ft) in height that have a minimum drop of 30m.  Accompanying the main P30 list are three sub lists; these are the 500m Subs, 490m Subs and the 490m Double Subs with their criteria detailed in the respective Change Registers which are linked in their above titles.

The list is co-authored by Michael Dewey and Myrddyn Phillips and the posts that have appeared on Mapping Mountains detailing the additions, reclassifications and deletions to the main P30 list and the sub lists appear below presented chronologically in receding order.






Mapping Mountains - Hill Reclassifications - The 500-Metre Tops of Ireland

Pigeon Rock Mountain North Top (J 261 250) - 500m Subs addition (2nd reclassification)


There has been a reclassification to The 500-Metre Tops of Ireland list due to a re-assessment of information on Ordnance Survey of Northern Ireland maps.  This is the second reclassification to this list since its data were re-evaluated for publication on the Database of British and Irish Hills (DoBIH).  The hill is situated in the central western part of the Mourne Mountains in the north-east of Ireland, and is positioned between the small communities of Hilltown to its north-west and Attical to its south.

Access to the hill can be gained from its easterly side where car parking near to the high point of the B27 road gives relatively easy access up its easterly flank; otherwise a more challenging walk can take in this hill whilst visiting a number of adjacent peaks following the course of the Mourne wall.

The hill is named Pigeon Rock Mountain North Top and its summit is positioned at J 261 250.  The south top of this hill is currently listed as Pigeon Rock Mountain with a 534m high summit at J 264 244 with 141m of drop.  Pigeon Rock Mountain North Top was not included in the Sub list that accompanied the main list when published on D0BIH as debate on its prominence favoured c 19m, however this has been re-assessed and detail from a number of Ordnance Survey of Northern Ireland maps have been examined, the details appear below:


OS historic map:  1749ft (530m converted to current datum) for north top and 1755ft (532m converted to current datum) for south top

Map 29:  534m for north top, no spot height for south top.

Harvey map:  534m for north top and 534m for south top.

Mourne Country Outdoor Pursuits map (OS of NI publication 1990):  533m for north top and 534m for south top.

Mournes Activity map (OS of NI publication [update from the Outdoor Pursuits map] 2009):  534m for north top and 534m for south top.


After re-assessment of the above data we have decided to include Pigeon Rock Mountain North Top as a new Sub adjoined to the main 500-Metre Irish list.

This now brings the overall total for The 500-Metre Tops of Ireland to 201 and the Subs have increased by two compared to when the list was published on DoBIH.

Thanks to Jim Bloomer for supplying historical map information and suggesting this hill’s re-assessment.



The full details for the hill are:


Cardinal Hill:  Slieve Donard

Summit Height:  534m

Name:  Pigeon Rock Mountain North Top

OS of NI 1:50,000 map:  29

Summit Grid Reference:  J 261 250

Drop:  c 20m


Michael Dewey and Myrddyn Phillips (August 2016)






Mapping Mountains - Hill Reclassifications - The 500-Metre Tops of Ireland

Knocknaveacal North Top (V 744 526) - 500m Top reclassified to 500m Subs (1st reclassification)


There has been a reclassification to The 500-Metre Tops of Ireland list due to a Trimble survey conducted by John Fitzgerald.  This is the first reclassification to this list since its data were re-evaluated for publication on the Database of British and Irish Hills (DoBIH).  The hill is situated in the western lands of the Beara Peninsula in the south-west of Ireland, and is positioned south-west of the small community of Lauragh and eastward of Ardgroom.
These details are retrospective as the Trimble GeoXH 6000 survey conducted by John Fitzgerald that resulted in the reclassification of this hill from the main 500-Metre P30 list to the 500-Metre Sub-List was conducted on 30th May 2015 in a rainstorm and fog.

Access to the hill can be gained from its easterly ridge that ascends over the 356m top of Cummeennahillan, or an extended circuit can be combined over the hills of Lackabane (Leaca Bhan), Eskatarriff East Top, Easkatarriff (Eisc an Tairbh), Coomacloghane (Com an Chlochain), Tooth Mountain (Cnoc na bhFiacal), Knocknaveacal South Top and finally Knocknaveacal North Top.

The hill is named Knocknaveacal North Top and its summit is positioned at V 744 562.  The hill was listed with c 31m of drop based on a 513m summit spot height and an estimated col height of c 482m.  To the immediate south of this hill is another hill that is given a 513m spot height on OSI maps, this southern top is included in the 500-Metre Sub-List with c 29m of drop and is named Knocknaveacal South Top.  When re-evaluating data for this list’s publication by DoBIH these two hills proved of interest as they could have been listed as either two qualifying P30s, one twin top P30, one qualifying P30 and one Sub (either way round), or one twin top Sub.

The survey by John Fitzgerald with the Trimble GeoXH 6000 resulted in a 509.1m summit height and a col height of 482.6m at V 74321 56081.  The dramatic decrease in summit height from the 513m map height to the 509.1m surveyed height and the surveyed col height of 482.6m gives this hill a drop value of only 26.5m.

This now brings the overall total for The 500-Metre Tops of Ireland to 201, please click {here} to access the list on DoBIH.


The full details for the hill are:


Cardinal Hill:  Hungry Hill

Summit Height:  509.1m

Name:  Knocknaveacal North Top

OSI 1:50,000 map:  84

Summit Grid Reference:  V 74439 56269

Drop:  26.5m


Michael Dewey and Myrddyn Phillips (November 2015)



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