Sunday 2 October 2011

The Admiralty Building and Underwater Cables Part 2

I am grateful to John Marchment for allowing me to publish his memories of Unst.
Unst Memories – John Marchment
"In 1955 I was working at UDE (Underwater Detection Establishment) at Portland and was appointed to a top secret project charged with laying a hydrophone array north of the Shetland Isles to detect Russian submarines coming out of the White Sea. Apparently we had agreed a joint project with the Americans to lay a series of listening devices on the deep sea floor to detect said submarines. The UK system would use a brand new process called cross correlation, which had just been invented by our research establishment in Teddington ARL (Admiralty Research Laboratory). Initially we were interviewed by the authorities to see if we were good enough to be cleared to top secret (and it took so long that we were all off the project 2 years later before we were officially cleared!!).
I was then given the task of measuring the earth currents in the ground as there were fears that our hydrophone cable up from the beach which had very small signals in them would be interfered with by the high power cables going up to drive the radar system. This meant making a small portable amplifier and many a pleasant day was spent on the cliffs around Portland Bill making our measurements. I was then involved in finding a suitable site for the hydrophone array north of the islands.
I first went up to Unst in March 1956. The journey itself was quite an adventure, train from Weymouth to Waterloo, underground to Euston, night sleeper to Aberdeen, then sail to Lerwick on the St Ninian steamer. (Left click on pictures to enlarge).

At Lerwick. John Leask was requested to fix an ‘overland’, which was taxi to Toft, ferry to Yell, taxi to Gutcher, ferry to Belmont and, finally a taxi to the Springfield Hotel in Baltasound. If all worked well, one could leave Weymouth about noon on day one and arrive in Unst in the afternoon of day three, but it could take much longer than that due to weather conditions etc. Some people opted to fly but that was no better as sometimes the planes didn’t fly for days due to fog or high winds!
I spent days on the cliffs delineating the route of the cable from the beach at Burrafirth to the lab on the second floor of the Navy building. The work was quite strenuous walking up and down the cliffs to the station but made even worse by the skuas which were nesting at the time and really did not want to be disturbed at all. I suffered repeated bombings and had to ask for assistance from the local team. (See Note 1. For the route of the Admiralty Cable to Burrafirth).

At that time there were, I think, 4 large diesel generators in a building at Valsgarth which we were told had been put there by the RAF to run their radar installation. We had the sole use of one generator. It is a well known fact that diesels do not like to run on light load and during 1956 most of the island had been wired with 230 volts from the generators (but it was intermittent as when the radar was at full power ‘they’ shut off the islands supply). This caused little or no problems to the bulk of the islanders as most of them just used the electric light to enable them to light their paraffin lamps more easily! The hotel, however, had quite a problem as they had fitted a 48 volt DC generator which charged a bank of 4 x 12volt batteries and all the bulbs were 48 volt. When the 230 A/C came all bulbs had to be changed but the 48 volt ones were kept handy as, when the A/C power went off, all bulbs had to be changed back and the hotel generator started. For entertainment we, the trials team from Portland, had installed a large tape recorder in the guests’ lounge to give some background music to the guests but I remember the recorder did not last long as someone tried to play it when the 48 volt DC was on and neither the batteries nor the recorder liked that at all.
We had a team of about 8 people staying up there and a hut was built alongside the hotel as a sort of overflow sleeping accommodation. When the ‘posh’ guests, who came up to fish, had the rooms in the hotel we were moved out to the hut. I think we integrated with the locals very well – we were invited to sheepdog trials, which seemed to involve drinking a lot of the local home brew – a sort of poteen made from potatoes I believe – and then going on to a supper, dance and singsong. This went on to the early hours – we didn’t really know the time as it was light all night.
I can remember the team being invited to a wedding ceremony of Bertie (Black or Johnstone - I cannot remember his surname?? ). Bertie had been assigned as my beater when I went up the cliffs as he came along to (a) help carry the gear and (b) he carried an axe handle to beat off the skuas that used to attack us as we wandered through their nesting sites. Not a safe occupation! Anyway Bertie (aged about 26-30) was courting a local widow who had 3 teen aged daughters and when they got married we were all invited to the ceremony which went on for best part of a week. The bride and groom left on the ferry for their honeymoon early in the proceedings and the crowd all went down to send them off. It was interesting to see Bertie give a peck to his new wife and then he went into quite a necking session with his 3 step daughters!! We always wondered how Bertie got on but we were leaving the island shortly afterwards as that was the virtual end of the project.
One other little ‘occupation’ that amused our team from the south was the fact that as Unst had the ferry on their side of Bluemull Sound when anyone wanted to come to Unst they had to call for the ferry. When the police did this (on their infrequent visits to the island) the few cars that were on Unst suddenly all went up on concrete blocks and of course they were never taxed!!
We went to sea in the ACS (Admiralty Cable Ship) Bullfinch (or sometimes ACS St Margarets), lowered a hydrophone to the bottom and had HMS Undaunted run towards us from beyond the Arctic Circle dropping 1lb. charges every 15 minutes so we could measure the received energy.
Picture courtesy of Bill Glover at:
Picture courtesy of Bill Glover at:
Photo courtesy of John Bryant at:

After several runs we chose the most favourable position, went back to base and loaded the 12 hydrophones and about 100 miles of cable.  On a personal note, those of you that know the area will know the wind blows quite hard most of the time and, effectively moored to the bottom (by the hydrophone and 15 miles of cable), we were exposed to the worst the weather could throw at us – it is lucky I am immune to seasickness!!  The hydrophones were laid in the chosen position and the cable was taken back to shore in Burrafirth. 
The rest of the team back in Portland had been developing the electronics and with the array down and the cable at the beach, the equipment was loaded onto a LCT, sailed up the North Sea and offloaded at the Baltasound pier.  The main local organizer of the transport and the station was a large gentleman called Bertie Henderson, who had been a whaler in his youth.

Bertie was a tower of strength throughout our stay in Unst. The equipment in the lab consisted of 12 amplifiers to bring the small signals from the cable up to a reasonable level and then the signals were fed to a large magnetic drum, 2 feet in diameter and 2.5 feet high, which rotated at high speed. The delayed signals were taken off and formed about 20 beams looking out northwards from the array. The beams were split in two and effectively multiplied together and when there was a source in each half beam it would show on the paper display, whereas the more normal noise would not be correlated and simply form a grey background.
While writing these ‘notes’ I think it worth mentioning the tragic story of HMSTiree.
This patrol vessel was one of the last coal fired vessels in the UK Navy, only did about 8 knots and was used as a target for a variety of trials by Admiralty Research Laboratory, our companion establishment in Teddington. It was fitted with a 1 Kilowatt transmitter which drove a large transducer which was towed over the stern; it could represent a submarine or a ship or virtually any signal one was prepared to feed into the transmitter. This gear was fitted into the store below the ratings mess deck and it was run by a man from ARL whose name, unfortunately escapes me at this range! Anyway during one trial the gear broke down and he removed the cage surrounding the gear in an attempt to mend it at sea. The Tiree was distinctly unstable and rolled a lot and one roll threw this poor fellow into the gear which was on (there was a safety lock when the cage was removed and the gear could not be turned on but this fellow may have over-ridden this so he could work on the gear!) and at 3000 volts he didn’t stand much of a chance.  The poor fellow was found a bit later still draped over the gear but dead as a dodo. Tiree returned to Lerwick and after the police and everybody had finished I was sent down from Unst as we still needed the source for our trials. The reason I was sent was that I am immune from seasickness so, naturally, I drew the short straw. Needless to say, I was ever so careful with the gear which I managed to mend whilst alongside. Then off we sailed to the north and did the trial successfully. We sailed on east-west courses at varying ranges from the hydrophone array so the team could set the gear up. At the end of the trial the weather deteriorated and we were tossed about so much that even the stokers were getting sick. In fact it got so bad there was a danger of losing steam pressure, which had to be avoided at all costs so the captain called for volunteers to man the boiler room. As I wasn’t sick, I felt it right that I should assist so I shovelled coal for several watches (as did the captain I should say) until we reached the safety and calmness of Lerwick a day or two later.

Photo courtesy of the Shetland Museum Photo Archive:
At other times during the trials we worked on board HMS Fetlar, which was of the same class as the Tiree (Isles Class - Trawlers & Minesweepers).

Having set the gear up in the lab at Saxavord, the final trial was to be with a submarine but one problem that the initial trials with Tiree had thrown up was that the navigation systems available in those far northern waters were inadequate to give the accurate positions that were really needed for the system to be proven properly.  Decca had not long been invented but, as the company had no plans to put one up in the Shetlands, we set one up ourselves.  The master station was at the top of Saxavord, with the 3 slave stations fitted in caravans and spread around as best we could.  One was on the cliffs above Skaw, I remember, and we tied the caravan down with wire ropes so that it wouldn’t blow away. Just before the trial started we went out and started the generators which would run for 24 hours - the length of the trial.  The submarine arrived and it was the time that we had a strong wind (which blew the 20 ton radar aerial into the sea – it was never found to my knowledge) and we got a message from the submarine that there were only 2 slave stations operating. 

We went to the one at Skaw and that, too, had disappeared into the sea. Winds certainly do blow in those latitudes!!
Everyone had stories to tell of the ghastly journeys to and from Unst - like waiting for 3 days in Lerwick for the ferry to arrive, and latterly, when some people used the flights from Aberdeen to Sumburgh, the delays were even greater - sometimes the planes didn't fly for a week. The accounts people at UDE were very sceptical at some of the subsistence claims that were submitted but the cream of the submissions was due to the head of the division, our boss. By September 1957 we had completed the station and were due to do a 2 day trial with a submarine to show the effectiveness of the system. The boss and a senior Admiral set off from Weymouth on a Sunday evening to arrive in Unst in time for the Thursday trial. We expected them to arrive on Tuesday evening but when they hadn't arrived on Wednesday we phoned John Leask who confirmed he had arranged an overland for them on the Tuesday. Now the overland had 2 boat trips, neither of which started in Yell.

Yell at this time had no boats and, more importantly, no hotels and what had happened was that the taxi, on arrival at the north end of Yell, had found the Unst boat would not run because of the weather (it was blowing up!). The boss ordered the taxi to return to the south end but by the time they arrived there the mainland boat said it was too rough to come over and pick them up. They were marooned on Yell, slept in a barn for 2 nights, missed witnessing the trial, which went well, and went home without reaching Unst at all. The final ignominy was that the boss and the Admiral arrived by ferry at Aberdeen too late to catch the night sleeper to London so the boss hired a train to take the Admiral back to London - that claim took several months to work through the system and from that time the boss never doubted another claim from anyone on the project!.
However, we completed the trial successfully and, although not witnessed by any Admiral, we told the US that our system was up and running and asked if we could do a joint trial with their equipment? Sadly, the US did not get their equipment into sea for another 4 years, by which time our equipment was in a poor state: it never really worked again and was mothballed in year 1960. I would have loved to have known what happened to it all and wonder where the cable is now – it contains miles of copper!!

Note 1. Route of the Admiralty Cables from Saxa Vord to Burrafirth.
I am grateful to John McMeechan for allowing me to reproduce the map below. He has walked to route that the cables took and used GPS to record  each marker post on the cable route.
Some of the route markers near the Admiralty Building can be seen in the three photos below:-
The current state of the cables below Buddabrake is evident in the next 3 pictures:-

Note 2. Report of the Fatal Accident Inquiry into the incident on HMS Tiree
The report below has been copied from the Shetland News dated  28 Aug 56. I believe that the Shetland News ceased publication in the 60's. Use of some zoom/magnification will be required.

From: The Shetland News 28 Aug 56
Other sections about the Admiralty Building & Underwater Cables are here:


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