Mapping Mountains – Summit Relocations – Y Trichant

Ffridd Top Llety (SJ 089 167)

There has been a Summit Relocation to a hill that is listed in the Y Trichant and which was initiated by LIDAR analysis, with the summit height, its position and the drop of the hill confirmed by a survey with the Trimble GeoXH 6000, which was conducted on the 5^th April 2018.

LIDAR image of Bryn (on left) and Ffridd Top Llety (on right)

The criteria for the list that this summit relocation affects are:

Y Trichant – All Welsh hills at and above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub category entitled the Sub-Trichant consisting of all Welsh hills at and above 300m and below 400m in height that have 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips and the Introduction to the list and the re-naming and publication history was published on Mapping Mountains on the 13^th May 2017. 

The name of the enclosed land where the summit of this hill is situated is Ffridd Top Llety and this was derived from local enquiry, and the hill is adjoined to the Y Berwyn range of hills which are situated in the south-eastern part of North Wales (Region A, Sub-Region A4), and is positioned between the B 4393 road to its north and the B 4382 road to its west, and has the small community of Llanfihangel-yng-Ngwynfa towards the west.

Ffridd Top Llety (SAJ 089 167)

As the summit of the hill is not on designated open access land permission to visit should be sought, for those wishing to do so there are two public footpaths that cross the field where the summit is situated and which come within a few metres of its high point.

When this hill was originally listed in the Welsh P30 lists on Geoff Crowder’s v-g.me website it was by the name of Bryn and its 347m map heighted summit location given as SJ 085 169.  Since this hill was first listed the Ordnance Survey Interactive Coverage Map hosted on the Geograph website has become available online and this map shows a second 347m map heighted summit positioned at SJ 089 167. 

Gathering data at the summit of Ffridd Top Llety

These two summits and their respective connecting bylchau were analysed via LIDAR and surveyed with the Trimble GeoXH 6000.  The resulting summit data is given below:

Bryn

LIDAR:  346.239m at SJ 08501 16871

Trimble GeoXH 6000:  346.367m at SJ 08501 16870

Ffridd Top Llety

LIDAR:  346.619m at SJ 08997 16749

Trimble GeoXH 6000:  346.551m at SJ 08997 16748 

Therefore, the confirmation of the position of the relocated summit is at SJ 08997 16748 and this consists of closely cropped grass in an enclosed grazing field, this position is approximately 500 metres east south-eastward from where the previous prioritised 347m map heighted summit of Bryn is located.

The Trimble GeoXH 6000 gathering data at the summit of Bryn with the position of the relocated summit of Ffridd Top Llety in the background on the left

The full details for the hill are:

Group:  Y Berwyn

Summit Height:  346.6m (converted to OSGM15)

Name:  Ffridd Top Llety

OS 1:50,000 map:  125

Summit Grid Reference (New Position):  SJ 08997 16748  

       

Drop:  69.6m (converted to OSGM15)

For details on the survey that confirmed the summit relocation of this hill

Myrddyn Phillips (May 2018)