Site Records


SiteName: Criggion Radio Station

Criggion
Montgomeryshire, Wales
SJ283144

Sub Brit site visit 6th May 2003

[Source: Andrew Emmerson]

VISIT TO CRIGGION RADIO STATION, 6th May 2003 Glorious weather made a visit to BT's Criggion Radio Station in Wales on Tuesday 6th May an even greater pleasure. "Craggy Criggion" lies in Montgomeryshire, close to the English border, between Welshpool and Shrewsbury. The trip was arranged in great haste as the radio station has now been closed (on 31st March 2003), with deconstruction of the transmitting and control equipment already at an advanced stage. The masts and towers will be coming down shortly, with the buildings then sold or demolished.

Photo:No. 3 medium wave (HF) transmitter building
Photo by Nick Catford

The location is extremely picturesque and rural, close to the banks of the River Severn (Hafren) on flat watermeadows immediately below a massive outcrop of granite, the 900ft (or so) high Breidden Hill. The name Criggion will be familiar to any one who has read Duncan Campbell's book 'War Plan UK' and its location to anyone who has driven from Welshpool to Shrewsbury, since the antennas appear to spring directly out of the hillside.

In a way they do, since the radio station's location was chosen specifically to reduce the number of antenna towers needed, using an anchorage point close to the Rodney's Pillar monument to support one of the arrays.


The station in the 1940's

The station was built here during World War II when it was felt that stray bombs intended for Coventry might put Rugby radio station out of action. Although they did not, an accidental fire nevertheless did, so the reserve station here at Criggion proved its worth very rapidly.

A number of transmitter and ancillary buildings of World War II construction are in place, as well as a large yellow and blue sign of the early 1980s proclaiming the site to belong to British Telecom's Maritime Radio Services division.


Inside the main building (medium wave transmitter hall, canteen and offices) is a large map of Post Office External Communications and a poster inviting staff to buy shares as part of the BT privatisation, so as you may gather, the place-and the equipment it housed-is a bit of a timewarp.

Secrecy has always surrounded Criggion although various publications have revealed that its role was chiefly defence-related, providing worldwide radio coverage on the VLF band to ships and submarines. For this reason it was treated as a secure site and staff mentioned that although they used to transmit signals for the Ministry of Defence, they had no idea of what the signals actually were nor any means of decoding them. The long wave building was equipped with a Bikini State board giving the current security state of the place and one of the staff there was amazed that we were taking photographs of equipment that until recently was covered strictly by the Official Secrets Act. A number of relics and souvenir items were recovered for display at the Hack Green bunker museum. These did not, however, include various charts and circuit record cards that gave clues to the close links that Criggion had with a number of defence communications locations in the UK.

Photo:The anchorage point and aerial winch on top of Breidden Hill
Photo by Ni ck Catford

The site covers 300 acres (formerly 400 acres but some was sold some years back) and not all the buildings are now used. The antenna wires weighed 42 tons and required the use of seven 25-ton winches to keep them aloft. Power came from two separate 11kV feeds and at one time four generator sets were also employed. The antenna system radiated between 35 and 40kW of radio power. At its height of operation some 170 people were employed here but now just 11. Our conducted visit covered a look around and inside the medium wave and long wave transmitter buildings plus a Land Rover trip (up 33% inclines!) to the hilltop anchorage point.

Currently the transmitting equipment is being dismantled, part for re-use and the remainder for scrap. The 680ft self-supporting towers (pylons) may be dismantled for re-erection elsewhere but the 720ft stayed masts will most likely be demolished and broken up on site. A number of normal trunk telephone circuits pass through the long wave building and these will have to be re-routed before the building can be sold or demolished.

VLF aerial feeder - Picture from Practical Wireless

This visit was a private trip arranged by a Sub Brit member, with numbers strictly limited by our host. Participants were (in alphabetical order) Nick Catford, Robin Cherry, John Fogg, Bob Jenner, Dan McKenzie, Rod Siebert, Robin Ware plus myself, Andy Emmerson. Many thanks are due to the BT staff, who showed us round and answered our questions with great patience.

Photo:The G tower during the demolition in 2003 taken from the top of Breidden Hill
Photo received from Glyn Thomas, Project Manager (Radio Services) - UKBM/BT Global Services

FURTHER READING (1)

  • Hari Williams: Craggy Criggion-Wartime Wizardry. Practical Wireless, September 2001, pp. 25, 28,29.
  • Radio. POEEJ, January 1946 (Vol. 38), p. 142.
  • Criggion Comes Of Age. The ETE Newsletter, May 1964. Post Office Wireless Stations, GPO report dated 5th December 1941 (at BT Archives).

FURTHER READING (2) Articles in the Post Office Electrical Engineers' Journal

  • Floods at Criggion Radio Station. POEEJ April 1947 (Vol. 40), p.37
  • Cook, A. and Hall, L.L. Criggion Radio Station. POEEJ October 1948 (Vol. 41), p.123
  • Creighton, J.L. The New Very-Low-Frequency Transmitter at Rugby Radio Station. POEEJ January 1969 (Vol. 61), p.232
    Gracie, J.A. Rugby Radio Station. POEEJ April 1939 (Vol. 32) p.16
    Hall, L.L. Anthorn Very-Low-Frequency Radio Station. POEEJ July 1965 (Vol. 58), p.114 [Thanks to Richard Lamont for this compilation]

FURTHER READING (3) Items on the WWW

  • MB21 (Mike Brown) Web Site - Lots of excellent pictures




Practical Trident disarmament
Baldock Radio
A history of Rugby Radio

Thales Communications Ltd.
Celtic League mailing list
Shropshire Star feature on Criggion

THE RAILWAY CONNECTION The bizarre nature of the Criggion branch, opened in 1866, closed in 1880, reopened in 1912 and finally closed in 1934, is summed up in R.W. Kidner's book Standard Gauge Light Railways. He relates: "An ordinary railway, facing a chronically infirm Melverley Viaduct (it had collapsed during the period between 1880 and 1911 when the line was derelict) would have spent time and money attending to the foundations. Not so the Shropshire and Montgomeryshire Railway. Miraculously there were produced a 3-ton locomotive and a L.C.C. horse tramcar, a light combination that could be relied upon not to strain the timbers, and which, slightly modified, outlived the more orthodox passenger trains on this line."

Probably the only film footage of the Criggion branch is found on this VHS tape available from www.wolvertonrail.co.uk/catalog/wrcatp_b.htm Vol.72 - Steaming Through Shropshire Part 2 - The Severn Valley 60-mins BR186 19.75 A nostalgic look back at the railways of South including very rare 1932 footage of the SHROPSHIRE & MONTGOMERY RAILWAY shows LNWR 0-6-0's, Ilfracombe Goods engines and petrol railcars between SHREWSBURY ABBEY, KINNERLEY and the CRIGGION branch.

For further pictures about this site continues here

[Source: Andrew Emmerson]

Home Page
Last updated: Tuesday, 04-Jan-2011 14:55:28 GMT
© 1998-2003 Subterranea Britannica