Mapping Mountains – Trimble Surveys – Carnedd Wen

31.05.22  Beddau (SO 185 977, not Trimbled) 

LIDAR image of Beddau (SO 185 977)

My two previous visits to this hill were in utter contrast to one another.  The first in June 2011 involved 15 miles of walking from the front door of my bungalow and back.  The second in September 2020 was with Alex Cameron and involved driving up the concrete access road to where car parking is situated adjacent to the wooden chalets in the wood at the summit.  On this second visit it took a matter of a minute or two to saunter to the high point.

On this occasion I was with Charles Everett and as we had an appointment at the cinema in Newtown we could not linger, and as Charles wanted to boost his P30 totals a hill or two were in order and this one fitted Charles’ needs perfectly. 

Charles at the summit of Beddau

I had come underdressed for hill bagging wearing a pair of Birkenstocks with shirt and jacket.  However, my North Face trousers could pass as hill walking attire, but still, Birkenstocks are not necessarily the best for bagging hills, but then again this summit could be visited barefoot from where a car can be parked.

Having remembered the entrance in to the complex from my last visit with Alex, we were soon heading up the concrete access road toward the top of the hill.  I parked at the last available space before the high point, which this time was even closer to when I visited with Alex. 

An appropriate pose when wearing Birkenstocks.  Photo: Charles Everett

From here it was no more than literal seconds to the summit.  I conquered the top before Charles, who was safely bringing up the rear.  I stood on top and adopted an appropriate pose with fists clenched wondering if this could be deemed an ethical bag.  Obviously it could, otherwise we would not have done it!

Charles soon joined me on the small area of the summit and we each took the obligatory photographs.  However, with a film to see we could not linger and a few minutes after arriving we were back in the car and soon in Newtown heading for the cinema. 

 

Survey Result: 

 

Beddau  

Summit Height:  126.0m (LIDAR) (significant height revision)

Summit Grid Reference:  SO 18549 97771 (LIDAR)

Bwlch Height:  87.9m (LIDAR)

Bwlch Grid Reference:  SO 18841 98344 (LIDAR)

Drop:  38.1m (LIDAR)

Dominance:  30.24% (LIDAR)

 

 

For details on the 1^st visit to this hill

For further details please consult the Trimble Survey Spreadsheet

  

Mapping Mountains – Significant Height Revisions – 100m Twmpau

 

Beddau (SO 185 977) 

There has been a Significant Height Revision to a hill that is listed in the 100m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis conducted by Myrddyn Phillips. 

Beddau (SO 185 977)

The criteria for the list that this height revision applies to are:

100m Twmpau - Welsh hills at or above 100m and below 200m in height with 30m minimum drop, with an accompanying sub list entitled the 100m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 100m and below 200m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 100m Twmpau by Myrddyn Phillips

The name the hill is listed by is Beddau, and it is adjoined to the Carnedd Wen group of hills which are situated in the south-eastern part of North Wales (Region A, Sub-Region A4), and it is positioned with the A483 road to its north-west, a minor road to its south-east and the B4386 road farther to its south-east, and has the village of Aberriw (Berriew) towards the north. 

When the original 100m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was included in the main P30 list with a c 120m summit height taken from the uppermost contour that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map. 

When the accompanying sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with c 36m of drop, based on an estimated c 124m summit height and an estimated c 88m bwlch height, based on interpolation of 5m contouring that appears on the Ordnance Survey 1:25,000 Explorer map. 

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

Since the original compilation of this list there have been a number of Ordnance Survey maps made available online, some of these are historic such as the series of Six-Inch maps on the National Library of Scotland website, whilst others are current and digitally updated such as the mapping on the WalkLakes website and the Magic Maps website. 

One of the mapping resources now available online is the Magic Maps website which hosts an interactive map originated from Ordnance Survey data.  This map has many spot heights not on other publicly available Ordnance Survey maps and for this hill a 126m spot height is given on the area of its summit. 

Extract from the Magic Maps website

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 image of Beddau (SO 185 977)

The summit height produced by LIDAR analysis is 126.0m positioned at SO 18549 97771, this is not a substantial height revision compared to some revised heights but it does come within the parameters of the Significant Height Revisions used within this page heading, these parameters are: 

The term Significant Height Revisions applies to any listed hill whose interpolated summit height and Ordnance Survey or Harvey map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis. 

The summit of Beddau

Therefore, this hill’s new listed summit height is 126.0m and this was derived from LIDAR analysis, this is 2.0m higher than the previously listed and estimated summit height of c 124m which was based on interpolation of the hill’s uppermost 120m ring contour on the Ordnance Survey 1:25,000 Explorer map.

 

ills of Wales, and are reproduced below@

The full details for the hill are:

Group:  Carnedd Wen

Name:  Beddau

OS 1:50,000 map:  136

Summit Height (New Height):  126.0m (LIDAR)

Summit Grid Reference:  SO 18549 97771 (LIDAR)

Bwlch Height:  87.9m (LIDAR)

Bwlch Grid Reference:  SO 18841 98344 (LIDAR)

Drop:  38.1m (LIDAR)

 

Myrddyn Phillips (March 2021)

 

 

 

 

Mapping Mountains – Trimble Surveys – Carnedd Wen

 

15.09.20  Beddau (SO 185 977, not Trimbled)  

Beddau (SO 185 977)

Since the 5-mile keep local restriction was lifted I’d been drawn to the land between Berriew, Llanfair Caereinion, Llanwyddelan and Bettws Cedewain.  I’d seldom visited this area and yet it is only a few miles south-west from where I live.  This is not surprising as with A roads to its north and south, the only reason for me to visit would be either to call in to see a friend (I have none in that area) or to bag a hill, of which there are many. 

It was this area of land that Alex Cameron sent me a screen grab of, with the summits of 23 hills highlighted.  Alex hadn’t visited any of these hills, whilst I had pre and post the 5-mile keep local restriction.  With map in hand and Alex’s screen grab I devised a route around 13 of them, which also gave the option for calling at some farms to make place-name enquiries and for me to sit out three of the hills that I’d recently surveyed. 

We met at Welshpool Railway Station at 7.48am.  It was good to see Alex again, although it had only been a short while since meeting him, Dusty and Tony to re-paint the trig pillar on top of Corndon.  We’d come prepared with a multitude of food goodies, all necessary maps and prior permission to visit one of the hills from the local farmer. 

The first hill on the day’s schedule is named Beddau, this is positioned about one mile south-west of Garthmyl and this was the only hill out of the 23 on Alex’s screengrab that is positioned south of the A483.  I’d visited Beddau once before in June 2011 as part of my training for the impending TMS surveys in the Fisherfield Forest.  During that visit I’d walked on the canal towpath from my home, visited Beddau and headed back; this amounted to 15 miles, which took me five hours.  Having done little research beforehand I was, on that occasion, surprised to find a chalet complex in the wood, a near golf course, a few dotted small lakes and a field of lamas.  Today was simpler, as we drove to within a few metres of its summit! 

Prior to this visit I’d LIDARed the hill and it is this result for both summit and bwlch that is given below.  Beddau is not a high hill, with LIDAR analysis giving it as 126.0m in height.  With the upper hill wooded, it seems to disappear in the landscape and merges inconsequently in to pastured fields and the surroundings rising ground. 

LIDAR image of Beddau

We approached from a sign posted turn to the Penllwyn Lodges and I continued driving up on a concrete road swinging around the northerly part of the hill.  This took us to a small parking area close to what looked like the reception. 

All was quiet as we left the car, with the summit of the hill only a few metres to the right of the continuation of the road.  It only took a couple of minutes between us leaving the car and topping out at the summit, and I had just enough time to take a photo of Alex walking up the road toward the high point. 

Alex heading for the summit

I’d switched the Trimble on when leaving the car and checked the grid co-ordinates against those produced by LIDAR; they matched, so we were at the right spot.  Although Beddau is swamped by concrete roads and chalets it retains attractiveness and this early in the morning also peacefulness, to its surrounds. 

As Alex stood a few metres away I set the Trimble up and waited for the 0.1m accuracy level to be attained before data should be logged.  Its position did not give much hope for this to happen as it was enclosed by trees.  After a few minutes I checked what I hoped would be its downward ebb to the required accuracy level, and as it was still on 2.0m, I closed it down, took a couple of photos and packed it away. 

The Trimble GeoXH 6000 set-up position at the summit of Beddau

I had hoped to gather Trimble data, but LIDAR will suffice, and with another 12 hills on our schedule we headed back to the car and down the concrete road sweeping around the upper southern part of Beddau and back to the main road for our next hill of the day. 

 

Survey Result:

 

Beddau  

Summit Height:  126.0m (LIDAR) (significant height revision)

Summit Grid Reference:  SO 18549 97771 (LIDAR)

Bwlch Height:  87.9m (LIDAR)

Bwlch Grid Reference:  SO 18841 98344 (LIDAR)

Drop:  38.1m (LIDAR)

Dominance:  30.24% (LIDAR)

For details on the 2nd visit to this hill 

For further details please consult the Trimble Survey Spreadsheet