Tuesday, 31 January 2017

Saxa Vord - The ADGE Data Links Buffer System (ADLBS) and Ship S

In 2010,  when I wrote a piece about the Link 11 System at Saxa Vord, my understanding of the equipment I was referring to was sparse: http://ahistoryofrafsaxavord.blogspot.co.uk/2010/10/link-11-at-saxa-vord.html   Since then I have learned a little and been helped a lot - I thought it was about time to try to rectify any misconceptions I may have caused.

In the mid 80's elements of the ADGE Data Link Buffer System (ADLBS) were installed at Saxa Vord. Some of the work included the erection of three tall towers. The tallest tower carried an antenna for a communications system known as IJMS (Interim JTIDS Message Specification, where JTIDS stands for Joint Tactical Information Distribution System). Another acronym which confuses things still further is used for the antenna on this tower, which is known as the UKAEGIS antenna (United Kingdom Air Environment Ground Information Segment).  Two more tall Towers were erected to carry Link 11 Antenna. 
Separately, a system called SSSB (Ship Shore Ship Buffer), designed by the defence contractor Rockwell Collins, was also installed.  The photo below shows the 2 Link 11 Towers, the UKAEGIS Tower in the distance between them and the site of the SSSB :

The tallest structure was the UKAEGIS Tower:
As far as I am aware it was actually mainly used in AWACS operations. The next picture gives a slightly closer view of the UKAEGIS Antenna:
 

The other two, slightly smaller, towers, carried antenna used to transmit and receive data and voice using Link 11 communications.

Each of these antenna was 9m long and weighed more than 500 Kg.

Link 11 communications normally employed UHF frequencies to communicate with airborne platforms like AEW/AWACS  or, HF frequencies with surface vessels.  ADLBS handled the UHF Link 11 communications using the antennas on the towers.  The longer range HF Link 11 communications were routed via a number of much lower antenna which were part of the SSSB; some of the SSSB installation can be seen below :

Another view of the SSSB masts, but from Zoom Earth:


In 1984 two concrete bases were constructed for the ADLBS shelters, these were known as the Link 11 shelter and the UKAEGIS shelter. The small building behind the UKAEGIS shelter hard-standing in the photo below used to carry the old Type 13 height finder, which was operational from Sep '57 until it was decommissioned in the middle of 1979. The base of the Link 11 Tower A can just be seen behind the Type 13 plinth.

The Link 11 comms were processed by Thorn EMI Electronics equipment in the Link 11 shelter; the IJMS comms were handled by NATO equipment located in the UKAEGIS shelter but were then fed through to the Link 11 shelter to be processed - hence the references to Link 11 and UKAEGIS on the sticker shown:

 The processed output was then routed to the Thorn EMI Electronics console for display:
 
There were considerable problems erecting a stable radome for the Type 93 radar but, before it was completed, the UKAEGIS and Link 11 Shelters were moved inside its plinth (probably in the early 90's, certainly before the autumn of 1993 when the Type 93 arrived on site).
Before the Type 93 was installed Unst suffered one of the worst storms in living memory, (New Year 1991/92).  Devastation occurred over much of Shetland and at the exposed Saxa Vord Top Site in particular. This next picture is from the Saxa Voice, the Station magazine, some years later. The Link 11, like much of the equipment on the Station, was off the air for some time. The remains of Tower A can be seen to the left of the Type 13 plinth in the following photo:
The extent of the damage is apparent in the next picture, of the 4 Saxa Domes (SATCOM, HF 200, S 649 & T 93), only the SATCOM Dome was left standing:
ADLBS was installed at RAF Buchan, RAF Saxa Vord, RAF Boulmer, RAF Neatishead and RDAF Faroes – originally the sites were all stand-alone.  In a subsequent upgrade, however, the five sites were networked together so that information could be shared between them.  Then, in an effort to reduce manpower required at Saxa Vord, the operator control functionality was re-located, so that Saxa Vord could be operated remotely from the mainland. 
The last radar was removed from Saxa late in 2005 and the station closed in April 2006.  Components  of ADLBS have since been removed from the site. However, the empty shelters are quite possibly still within the Type 93 plinth (although its associated  radome was demolished in 2014).
 
I am grateful to Cyde Walker (Thorn EMI, Racal, Thomson-Racal and Thales) and Pete Brindley, RAF for their assistance. Nevertheless, I accept full responsibility for any mistakes.
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Friday, 30 December 2016

Arctic Circular - Jun 85

Left click on pages to enlarge
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Wednesday, 30 November 2016

Clyde Walker & Saxa Vord


Clyde Walker was never posted to Saxa Vord and he was never in the RAF. However, he did visit the Station on a number of occasions. In the late 70's Clyde, and his then girlfriend Ali, worked for several years with an ex RAF serviceman called Bill Borthwick in Hertfordshire. Bill had completed a tour on Unst in the early 60's and Clyde remembers Bill mentioning a remote posting he once had and that he'd played in a band - the details didn't sink in at the time!: http://ahistoryofrafsaxavord.blogspot.co.uk/2016/07/bill-borthwick-saxa-vord-196364.html

Early in 1983 Clyde and Ali got married. They moved to Somerset a few months later when Clyde got a job with Thorn EMI. At about the same time Bill decided to return to Edinburgh, his home city. Clyde had joined Thorn EMI as a Quality Assurance (QA) Engineer but, when a planned project was delayed, he was assigned to another project known as ASR894 (ASR= Air Staff Requirement). For sensible reasons the scheme was known as ADLBS (short for Air Defence Ground Environment Data Link Buffer System). In July 85 Clyde was to gain experience of Unst for the first time when he was sent to perform a QA assessment on the recently installed ADLBS System at Saxa Vord.
He was scheduled to fly from Heathrow to Edinburgh and then transfer to a Loganair Flight to Shetland (a Shorts 330 to Tingwall and then an Islander on to Baltasound) As many of you will know airline schedules are not always dependable. The flight was late leaving Heathrow, Clyde missed his Loganair connection and had an unexpected night-stop in Edinburgh. He managed to get in touch with Bill by phone and it was only in conversation during that night out that Clyde discovered that Saxa was the place that Bill had referred to years earlier.  On completion of this trip to Unst Clyde returned to Thorn EMI and soon was reallocated to a new post:

" In 1986 I left the QA department and became the manager of the contract that had, by then, come into force for the support of the ADLBS (still at Thorn EMI).  I was therefore in charge of the task to replace the Link antenna / tower that had collapsed during the infamous storm of 1992 – although I wasn't part of the on-site team.  We had to get a new tower manufactured and used a spare Link 11 antenna for the replacement activity; meanwhile the antenna that had collapsed was returned to Somerset for refurbishment by the original manufacturer.  The Link 11 antennas don't look that big when they are up on the towers but they are over 9m long and weigh over 500 kg!"
 

 

It was a number of years before Clyde returned to Saxa:  "My next visit to Saxa Vord was in 2005, when I was part of the on-site team installing and commissioning an update to the processing equipment used in the ADLBS.  I still remember walking up the 278 steps between the top and middle sites on a daily basis!"  Fortunately, he had a camera with him and he took the following sequence of photos on that trip:





 

The final picture in this group shows the Type 93 Dome and was taken between 29 Mar and 8 Apr 2005. The significance of this is that the photo will be among the last taken of Saxa when there was actually an operational radar on site. The Type 93 was dismantled and left Unst in the autumn of 2005.
 

Clyde returned to Saxa Vord in 2011 and , in his own words, "Sadly, in 2011 I was part of the team to switch off the ADLBS at Saxa Vord for the last time, remove all the electronic equipment, racks and console and drive it all back to Somerset for repair / test, so that it could be used as spares for the remaining ADLBS sites (by then Buchan, Boulmer and Neatishead)".  Luckily, Clyde had a camera with him on this visit too. 

In June 2012 the Operations Site (Mid Site) at Saxa was auctioned, with the RAF retaining the Radar (or Heads) Site. However, preparations for the auction were made well in advance and, by the time of Clyde's visit in 2011, a new chain-link fence had been constructed to separate the Heads Site from the Ops Site. Amongst other things this necessitated the dismantling part of some of the covered walkway between the two sites. Evidence of this change can be seen in the following photos:



The next photo has what looks like the old Type 13 plinth in the foreground (if I'm wrong I would be very happy to be corrected!)

The building in the next picture is much more modern and I'm sure it was used in a ground defence role:

The empty Type 93 dome can be seen in the background of this next photo but my particular interest is with the low structure in the foreground, which looks as if it has been made from locally manufactured blocks. It looks old & it may well have been intended for a different purpose when it was originally put together - if anyone knows its history I would be very pleased to hear from them.

One object, which was in situ long before the first RAF servicemen were on site, was the trig point. It became a familiar sight to many, especially in the days when the mast alongside was the home for an anemometer.
 


All UK Ordnance Survey Trig Points are individually numbered and the one on top of Saxa Vord is no exception:


 
In 2014 Clyde was made redundant ."By then, Thorn EMI had gone through several incarnations as Racal then Thomson-Racal then finally Thales - but when I left I was still in charge of the ADLBS support contract, having been associated with the project continuously for the 31 years of my employment there. "
Clyde's wife, Ali, had often said she would like to visit Unst and the two of them finally travelled north in Sep 2016 and took this last, long range photo of the Saxa top site:
 Clyde and Bill Borthwick lost contact for about 30 years.  However, during their visit to Unst, Clyde & Ali were amazed to see a photo of Bill and of his band, The Hustlers, taken by Denis Coutts in 1964.  Knowing the name of Bill's band was then the key to them finding this blog and the information on Bill.  Clyde & Bill have now re-established contact.
My thanks to Clyde for allowing us to share some of his memories & pictures.
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