S649 - The End, Memories from Maurice Henderson

During the 70's RAF Saxa Vord was largely re-engineered with the aid of £10 Million of NATO funding. The Type 13 height-finder was finally retired and replaced by a Plessey HF200. After more than 20 years of service the Type 80 search radar was replaced by a new Marconi S649, with back-to back reflectors mounted on the same turntable. One reflector was for a D band radar and the other for an E/F band radar (for those of you as old as me the radars were L & S band). Both the HF200 and the S649 were enclosed in radomes from the beginning.

 

In the late 80's it was decided to add a tactical, transportable radar, enclosed in its own radome.  This was to be the Type 93, which was a 3D radar, capable of finding range, bearing and height with a single head, doing away with the need for a separate height-finder. During construction the Type 93 radome collapsed twice, in Jun '89 and again in Sep '89. The "golf ball" was completed in 1990  but the new radar was not ready for delivery to Unst.

As many of you will know Shetland and particularly the radar site suffered severely in the gales at New Year 1991/92: http://ahistoryofrafsaxavord.blogspot.co.uk/2010/07/storm-new-year-199192-part-1.html  The only operational search radar at the time, the S649, was badly damaged and its 65' diameter radome was a total write off. Pictures from before and after the gale:

The wind also totally destroyed the 110' diameter radome which had been erected to house the, as yet undelivered , Type 93. Saxa Vord, a major link it the NATO air defence chain was non-operational.

With the cooperation of the civilian authorities, a number of operations personnel were detached to Sumburgh Airport on the Shetland Mainland, where spare Air Traffic facilities were used to provide some radar cover in Saxas area of responsibility. In the meantime, senior officers, engineers & contractors got together to see what could be done to permit the Unit to resume its full operational role.  On the plus side the Type 93 radar would be coming, though work on building  a radome for it would have to start again. In January 1992 probably few realised it would be nearly 2 years before the Type 93 would be operational.

In order to provide a search radar as quickly as possible it was decided  to recover the S649 without a radome. The damage to the E/F Band side of the radar was so severe it was agreed not to repair that part of the equipment but to concentrate all efforts on making the D Band radar operational. The main Contractors (Marconi) and RAF personnel had a busy time before the S649 became serviceable again in November 1992, ten months after the storm.

For a year, until November 1993 when the Type 93 was accepted,  the S649 enabled the Unit to meet its NATO commitment. A new radar on site - surely time to retire the old equipment? Unfortunately, new equipment frequently has teething problems and personnel can take a while to get used to new technology.  It wasn't until April 1995 that the S649 was finally decommissioned. The contract for removing the  radar and it's plinth was awarded to Malakoff & Wm Moore Ltd, a Lerwick based company which had been in the engineering business for around a hundred years.

In the summer of 1995 Maurice Henderson, a Shetlander, got a job with Malakoff in his University holidays . He was one of a small number of people  sent to Unst to demolish the S649 and, fortunately for us, he took his camera with him. It would be best to let him tell the story in his own words:

"We spent almost 6 weeks taking down the radar.  Much of that was waiting for calm enough weather to use the crane on top of the hill. Danny Arthur, Harry Ratter, Sydney Sinclair and myself were based up there.  Michael Jacobson came up near the end with a digger to use the rock breaker to chip out the base blocks.  The stone was incredibly hard and said to be bomb proof concrete.  We also had a second crane hired from OIL at one point to do a tandem lift to take out the heavy gear box.  About 8 or 9 tonnes if I recall correct.

The huge bottle screws were a couple of hundred weight each that held on the dish bit of the radar and Danny Arthur walked along the top of the pipe cutting them as he went the whole structure shaking under his feet when the cut through.  He was harnessed on but I wouldn’t have fancied it.  I remember it quite dramatic at night,  I had the escort van tied on to the corner to keep the strain against the wind. Felt a bit like being in a thunderbirds episode ha ha!

It ended up we had to get another crane up the hill and do a tandem lift for the gear box and motors, which were much heavier than estimated and at quite a reach for the crane.  It took a number of weeks to get a day when the wind dropped to a safe level to remove the large bits of the structure. 

 

We had to get in a JCB rock breaker to chip away the last of the concrete base which seemed to be particularly tough, bomb proof they said.  Made from special stone shipped in from near Inverness, and a serious lot of reinforcing.  Whether that was true or not it was a tough pick even for the JCB rock breaker, our pneumatic windipicks were of no use. We took the whole structure down and left the place with a clean concrete base.

The centre pipe went to Uyeasound where someone was hoping to use the sections to build a bit of a pier - not sure if he did or not.  We got a few folk looking to scran stuff but the wave guides and a lot of the materials were some fancy alloys that did not cut easily (Note: up in Shetland Scran means to acquire cast-off materials, unlike some parts where it's another word for food - particularly in the Royal Navy)

We stayed with Nancy Hughson at Ordale and were extremely well catered for, and all put on a fair bit of weight!  Never seen grub like it. A fantastic time we had in Unst a very memorable job, got to know the island quite well.  Still one of the most enjoyable summers I have spent, loved it in Unst."

The following pictures all belong to Maurice and they illustrate his summer perfectly:-

 

I would like to thank Maurice for allowing ne to use his anecdotes and excellent photos. Before finishing, a couple of notes:

 1. One of Maurice's grandparents, Maurice Gould (an accomplished musician), served at RAF Skaw on Unst during WWII. He will be mentioned in a piece I plan to write about the Chain Home radar station.

 2. Maurice Henderson himself is also an accomplished musician and is a member of the well known Shetland group Fiddlers' Bid : https://www.youtube.com/watch?v=ZUkXJ7Kp6ZY

 CONTENTS LIST

http://ahistoryofrafsaxavord.blogspot.co.uk/2012/03/contents-list.html

 

 

 

 

 

 

 

RAF Noss Hill - Air Ministry Experimental Station (AMES) No 54 - (Amended 16 Nov 18)

At the beginning of WWII the UKs Chain Home RDF system stretched along the south and east coasts of England and up the east coast of Scotland. However, the most northerly station was at Netherbutton, near Kirkwall,  in Orkney and the equipment there was designed to look primarily to the south-east. In the early part of the war, with all three services having strong operational requirements for this technology, manufacturers of RDF (radar) components had difficulty keeping up with the demand and it was necessary for priorities to be established. Nevertheless, the allocation system had to be flexible to meet new needs. In April 1940 German forces invaded Denmark and Norway leading to the decision to expand radar cover in the Northern Isles.

From the Shetland perspective this meant the immediate formation and dispatch of a radar unit to Unst (No 3 Transportable Radio Unit - http://ahistoryofrafsaxavord.blogspot.co.uk/2013/01/the-first-radar-on-unst.html). It was also decided to build two permanent sites in Shetland, at Noss Hill at the south end of the Shetland Mainland and at Lambaness, in the north of Unst. Both of these sites would become operational as Advance Chain Home (ACH) stations, quicker and simpler to construct than the full Chain Home (CH) stations, whilst work on the more substantial Final CH equipment and structures continued. The site at Lambaness on Unst (RAF Skaw) will be described in later sections, this article will be confined to RAF Noss Hill.

Noss Hill is just south west of the Loch of Spiggie and about 3 miles north-west of the airfield at Sumburgh. The summit of Noss Hill is 367ft  above sea level and, when construction began, there was already an operational Navy radar (AES1), mainly looking for surface plots, at Sumburgh Head. (Left click on pictures to enlarge).

The ACH unit at Noss Hill consisted of a domestic site, two 90ft wooden towers for the Transmitter and Receiver aerials and 3 huts, surrounded by blast walls. The huts were for the diesel generators, transmitter and for the combined receiver/ops room.

In greater detail the ACH Ops/Tech Site looked like this:

The next picture shows the ACH Tech/Ops area from the north-west. The blast walls for the Receiver Hut can be seen in the distance, the power would have been located in the compound centre left and the transmitter hut centre right:

The next photo shows the blast walls which surrounded the Receiver Hut, the footings for the 90ft aerial tower can be seen on the right.

The walls constructed to surround the Transmitter and Receiver are of similar size. Very little, other than sheep droppings, is left inside the blast walls as can be seen from  the following photo, taken where the Transmitter Hut used to stand.

The area which housed the diesel generator is a different shape from the compounds which housed the "T" & "R" Huts, it also has a much larger concrete foundation inside. There are a couple of apertures, which can be seen in the far wall in the next picture - these were possibly used to convey the exhaust fumes from the diesel engines out of the confined space.

Whilst the footings for the "T" & "R" aerial towers were of concrete and steel, the towers themselves were 90ft tall and made of wood. The legs formed a 10ft square at the base and each leg was 5" x 5".

The larger Final Chain Home site took much longer to build and was massive in comparison to the initial ACH unit. The aerial towers dwarfed their earlier cousins and the Transmitter and Receiver/Ops blocks were larger and contained in hardened bunkers.  A hardened Standby Set House, with back-up diesel generators, was also constructed. The labelled extract from Flash Earth shows the main Op/Tech buildings on the CH Site - better descriptions and illustrations will follow.

One of the structures marked on the plan above would not have been there when the CH site took over operations from the ACH site, that containing the IFF equipment - more on this later. I do not have a completion date on the VEB so that may also have been constructed after the rest, once again more later.

CH Transmission

Firstly, I'll take a look at  the transmission side of the Noss Hill CH station. Unfortunately, the bunker which used to house the transmitter equipment is sealed and entry is not possible. However, some details are evident. It's exterior dimensions and shape are the same as the similar building at RAF Skaw - the block measures 72' x 26'. The first two pictures show the outside of the Transmitter Block.

There are some small holes in the wall which appear  to reveal the Transmitter Room at the western end of the block and a very small broken window at the eastern end of the block which reveals  a large chamber, part of which can be seen below:

The radar construction programme in UK was an immense undertaking and, to help speed-up progress, standard plans were drawn up for each type of installation. These plans were adapted to a certain extent on site dependent upon variations in available material and local features. For CH radars there were two main types of plans, those for the earlier east coast stations and those for the later west coast units. The differences were significant with regard to equipment, towers and buildings but rather complex for explanation here. RAF Noss Hill and RAF Skaw surprised me in having features associated with both east and west coast CH Sites. At both sites the layout of the Transmitter Blocks follow the plans for a standard east coast CH site, though with the inaccessibility of the Noss Hill  structure. it's difficult to discover what equipment was inside.

The two Transmitter towers were massive steel structures ABOUT 360 ft tall and could be seen from long distances. At ground level the 4 legs of each tower formed a 64 ft  square. The following picture, taken just after the war and held by the Shetland Museum & Archive Photo Library, shows the site from the north with the Loch of Spiggie in the foreground - the Transmitter towers are the 2 tallest on the left.

CH stations operated on two wave-bands - 10.10 to 13.27 metres and 5.9 to 7.1 metres. Most CH Stations used wavelengths in the longer band. For comparison, the Type 80 search radar, which was introduced in the mid 50's and installed at Saxa Vord,  had a wavelength of about 10 centimetres and the Lightning fighter airborne intercept radar - the AI23B - had a wavelength of about 3 centimetres.

 

Note:

 

During my visits to the Noss Hill CH site the Transmitter Block was sealed. I recently heard from Sammy Sjoberg who has been able to gain access to the building. He sent me photos of the inside and has kindly allowed me to attach some of them to this article.  Considering its age the structure the interior seems to be in excellent condition. I have added a sketch of the RAF Skaw Transmitter Block. which was similar, to provide an idea of the layout: