Military protection of Marconi LW station?

[MUU]

Returning after some years away from the GWF (new user name - such is memory!)

I wonder if members would be so kind as to have a look at the images of this near-ruin, which is above the 1914 long-wave transmitting antenna site to the east of Caernarfon (then almost always termed 'Carnarvon' - this helps online searches greatly!)

There is a claim in an official archive record that the fluted holes in all elevations of this building (though many were apparently immediately and permanently stopped-up) were to enable guns to be fired at any approaching enemies intent on harming the antenna. The building is extremely exposed at 1500 feet amsl, with the Irish Sea coast just 6.5 miles away.

Any assistance in interpreting the building will be greatly appreciated and acknowledged in the report that graphically reconstructs the whole antenna site. If you have any similar examples I can point to, that would be very useful, too.

Thanks very much!

 

[awjdthumper]

The site of the Cefndu Long Wave Wireless Transmitter was surrounded by blockhouses for protection. The one in the picture is blockhouse No. 5. I'll have a closer look tomorrow to see if I can identify where the remains of the other blockhouses where.

 

[Moonraker]

In contrast, the Marconi wireless station near Devizes had very little protection. Iron work for its construction was due to arrive at Devizes in the first week of 1914, when Marconi's wanted fencing around the site to prevent workmen damaging adjoining property (the golf-course?). The Postmaster General was prepared to erect interlocked wire fences around the masts and buildings. The Marconi's plan in the National Archives marks a fence around each 300-foot mast with the note that "This fence is not supplied by Marconi's Wireless Telegraphy Company" and "No fence is required for mast near the receiving station".

A memorandum of June 12, 1914 by the Committee of Imperial Defence's committee responsible for the wireless chain stated that "it was not proposed to take any measures for the defence of the receiving station at Devizes in time of war" though the station at Leafield would be surrounded by a fence. (PRO file: CAB 16/32) This is surprising given the importance attached to guarding railways and reservoirs. (Nigel West, in GCHQ [Weidenfeld and Nicolson 1986, page 16], implies that "fortifications", including fences and bullet-proof shutters, for the Devizes site were being discussed in December 1913).

I would imagine that when, during the war, the station was taken over by the army as a monitoring station, there would have been a need for security, perhaps provided by the Royal Defence Force, rather than protection against enemy action.

(I continue to regret that I've seen hardly any 1910-1920s photos of the site - just a few taken privately of personnel. I imagine that photography during the war would have been forbidden, but it functioned until 1927.)

 

 

Edited 24 May , 2022 by Moonraker

[awjdthumper]

The Cefndu station was taken over by the Admiralty and was surrounded by a fence and eventually had 10 x block houses to guard it. I do not know much about the transatlantic wireless network at the start of WW1 but the difference in security at the two sites mentioned may have been that the Cefndu station was transmitting and therefore had some very expensive transmitter electronics whereas the Devizes station may have been purely receiving and the only electronics needed was a simple receiver. I doubt whether the actual aerial system and its tall masts needed much guarding?

[MUU]

Thanks for all the information thus far - very much appreciated.

I haven't moved from the main work of understanding the antenna system to the blockhouses in detail yet, but it's clear there are at least five still easily identifiable, if mostly in a collapsed state!  The inclusion of the firing holes, all of which have (quite poor) lintels of fluted slate at top, is a good way to confirm any pile of rubble found was a blockhouse.

The much smaller blockhouse depicted lies at the head of an incline used to bring material up the mountain to build the massive concrete tower bases and stay anchors. It's clearly made only partly of brick, so the stone elevation may well have been part of a winding house for the incline, especially as the blockhouse is now slightly offset from the centreline of the incline. But I haven't examined it in detail yet.

 

Edited 24 May , 2022 by MUU

[shaneJ]

[awjdthumper]

I understand that the remains of 9 out of the 10 blockhouses built up to 1915 are still visible on the ground. I believe the remains (concrete base) of blockhouse No. 1 are adjacent to the Chamois Mountaineering Centre which was originally the entrance to the site. I believe the remains of blockhouse No 2 can be seem a few hundred yards to the NE of the end of Marconi road and the heritage centre.

At one point, the aerial was used to radiate 400 kW of RF power and the site therefore consumed an enormous amount of hydro-electric power to supply this. I wondered at the start of this thread why such a transatlantic Tx station was needed given that undersea telegraphy cables had been operating for more than half a century. The answer seems to have been because of concern that the undersea cable could be cut whereas the wireless network could always be relied upon. Looks like a fascinating site and I would be interested to know more about it.

 

 

[MUU]

Wow!  Thanks! Is the map of Waenfawr, too? 

J.

Edited 24 May , 2022 by MUU
New thought

[shaneJ]

There was no hard and fast style for Blockhouses for wartime use. At Clifden they were hexagonal and at Carnarvon they were rectangular. These were the 2 largest Marconi Stations in the British Isles at the time. Carnarvon was under test when war broke out. Clifden corresponded with Nova Scotia and Carnarvon with New York. The stations were taken over at the start of the war by the Admiralty. The file "Map referred to within.."   is a WW1 Admiralty station with at Bunbeg Co. Donegal. This map has a rectangular and an Octogonal blockhouse.   

[awjdthumper]

The purposes of the blockhouses appears to have been to allow the guards to keep the whole perimeter of the site under observation in order to make it difficult for saboteurs to gain access to the site. It looks as though the blockhouses were outside the perimeter fence.

However, it is not clear to me why blockhouses as such were used unless the Admiralty were planning for the possibility of a large scale assault. Normally, you would expect any guard houses to be inside the perimeter with patrols sent out regularly to check on any breaches of the fence. There was a lot of RF power radiated from the aerial array but I can't see any real reason why this would have forced the guards to operate just outside the fence. Given the fact that some of the blockhouses were several hundred yards apart, would it have been that difficult for a small group of saboteurs to have breached the fence at night and gained access to the site?

[Hywyn]

In terms of who was guarding Marconi Waenfawr the RWF 6th Bn TF Association Minutes (at Caernarfon County Archives) provides some information

e.g .

minutes for 6 11 1914

"No 1 Defence Company 6^th RWF (Defences) stationed at Waunfawr. 3 Officers, 117 OR."

4 12 1914

"

National Reserves.

Correspondence received from C O , Chester.

“ Please enrol another half company National Reserves, 1 Officer, 59 men making three and a half companies in all”

Major Sir T Neave, Bart, Commanding No 2 Coy had been asked to recommend a suitable National Reserve Officer and carry out the enlistment of the 59 men. He reported by letter that the General Staff Office at Chester requested a highly capable Officer at Conwy Bridge to take charge. He also intimated that there had been a great deal of ‘weeding out’ carried out in the other 3 companies in order to uphold their reputation. He had no National Reserve Officer to recommend and recommended that suitable NCOs be promoted. He recommends one of the following. QMS Hammond, Barracks, C’von. Col Sgt George Green, No 2 Def Coy. Sgt J J Knight of No 1 Coy (under Captain Breeze)

Letter from Captain C E Breeze, commanding No 1 Coy, 6^th RWF, Waenfawr. He is awaiting transfer to the Welsh Army Corps. He recommends Sgt J J Knight for promotion. He also recommends Lts O T Evans and J L Mayger for promotion.

Motion carried 1) that QM J T Hammond be recommended for commission and 2) should there be further vacancies for officers in the National Reserve Coys then QSM Green and Sgt J J Knight be submitted for appointments to 2^nd Lts."

18 12 1914

"Accommodation at Waenfawr. Contract arranged for hutting accommodation with Messrs Jones Bros, Bontnewydd, specified time for completion 5 weeks minimum, 17 weeks maximum.

 

Motion passed that Lt O T(or F?) Evans be recommended for promotion to Captain, No 1 Coy, Defences and Sgt J J Knight be recommended for Lt in that company.

Lt J L Mayger, No 1 Coy 6rth RWF National Reserves has applied for transfer to 6th Reserve Bn. Committee recommends Mr Ralph Fisher, Llandudno National Reserve for commission to No 1 Coy."

 

                                  ------------------------------------------------------------------------------------------------------------

 

 

 

The men received their initial numbers from the 6th Bn RWF number sequence. When the unit was designated as No 1 Supernumerary Coy they were renumbered to 5 digit numbers starting with 20xxx and then in April 1916 when the RDF was formed they became 326th Coy, RDF with RDF numbers ranging from roughly 19450 to 19579. I have identified most of them from AVL, records etc.

 

 

 

 

[awjdthumper]

Here's a nice picture of Blockhouse No 2 which was close to the transmitter buildings showing railway track beds - looks very similar in design to the blockhouse picture at the start of this thread.

[awjdthumper]

Here's what the Waunfawr transmitter station looked like around 1914 showing the 10 x 400' high steel masts between which the aerial wires were strung over a distance of about 1 km. The 442 m high Cefn Du hill is in the distance

[MUU]

4 hours ago, awjdthumper said:

Normally, you would expect any guard houses to be inside the perimeter with patrols sent out regularly to check on any breaches of the fence.

The only help I can offer there is that the houses are all in locations with commanding, elevated views of the sloping approaches to the perimeter of the site. From a map, it isn't very evident that the ground on which the antenna stood is in a bit of a shallow boggy valley, where visibility looking downhill is not only poor, but impossible for all but the NW direction.  The fence such as it was, amounted to nothing more than a modern-height animal fence - at least two iron fenceposts remain.

[MUU]

2 hours ago, awjdthumper said:

Here's what the Waunfawr transmitter station looked like around 1914 showing the 10 x 400' high steel masts between which the aerial wires were strung over a distance of about 1 km. The 442 m high Cefn Du hill is in the distance

 

Yep, that's a good photo, widely circulated, but hides a massive amount of detail. My interest isn't specifically in the WW1 period alone, but the whole lifetime of the site. The antenna was extended to the rear by 900' in 1920, and shortly thereafter split into an upper and lower section working different wavelengths. A second, inductively-coupled antenna was installed in 1923-4, which ran from the left rear of the antenna as shown in your photo and ran quite steeply downhill towards Llanberis (second image, of lattice tower). The first image of one of the main support masts, also 400' tall and identical to the one at C'fon, is from Marion, MA in the US.  You can see some of the massive ceramic egg insulators, shown in the third image.

Edited 24 May , 2022 by MUU
Some detail missed-out

[MUU]

3 hours ago, awjdthumper said:

Here's a nice picture of Blockhouse No 2 which was close to the transmitter buildings showing railway track beds - looks very similar in design to the blockhouse picture at the start of this thread.

 

Wow! I wonder which year that was?  It is the very-same blockhouse. The railway tracks are clearly visible, whereas today, they are essentially invisible. Quite amazing. Thanks a lot - very valuable indeed.

Edited 24 May , 2022 by MUU

[MUU]

18 hours ago, awjdthumper said:

 I wondered at the start of this thread why such a transatlantic Tx station was needed given that undersea telegraphy cables had been operating for more than half a century. The answer seems to have been because of concern that the undersea cable could be cut whereas the wireless network could always be relied upon.

 

 

German Imperial cables were cut to a crippling degree, and in R.N. Vyvyan's 1933 book, Wireless Over 30 Years (reprinted 1974 as Marconi and Wireless, and which, I should note, does include some errors, later repeated by others, of understanding about sites he wasn't very familiar with), the concern about British Imperial cables being cut, whether undersea or otherwise, was considerable. The station was intended for commercial communications and in keeping the Empire in touch. It opened almost coincidentally with the onset of WW1, so was quickly protected as a vital means of communication. It was not included on public maps for a long time. 

[Dai Bach y Sowldiwr]

The building was clearly visible on the hillside from my childhood home in Anglesey.

[Hywyn]

@MUU

Short newsreel of the demolition of the masts in 1939 in case you haven't seen it.

https://www.britishpathe.com/video/felling-wireless-masts-at-caernarvon/query/caernarfon

 

[Spaceman]

An interesting news reel. Given that modern tall radio masts are made from lattice constructions, I find it intriguing that they made these 400' masts from steel tubes that were bolted together. It must have been a terrifying job to have constructed them?