the invasion of Poland, Britain declared war on Germany on 3 Sep 1939. After the quick German success in Poland a
period of about 6 months ensued, now sometimes known as the “phoney war”, when
it might have appeared that Germany could be resting on its laurels and
concentrating on absorbing its new territories. Then on 9 Apr 1940, probably
surprising most of the British establishment, German forces invaded both
Denmark and Norway.
WW1 most British forces were involved in fighting in France and Belgium with
the main threat to the UK being to the Home Counties. The sudden invasion of
Denmark & Norway in Apr 40 shifted the threat axis. A look at the map below
will help understand the planner’s reactions. (Left click or zoom on pictures to enlarge):
German campaigns would bring airfields from which they could operate against
Scapa Flow – base of the UK Home Fleet. It would also bring RAF Sullom Voe
within range – since Aug 39 Saro London and Sunderland Flying boats had been
based there – essential in helping to prevent German surface ships &
u-boats getting easy access to the North Atlantic. The capture of an island or
two in the Hebrides, Orkneys or Shetlands could establish a base to launch an
attack against a sparsely populated and less well defended part of UK.
been sympathetic to the allied cause and both France & Britain had treaties
with Norway. For once the British reaction was almost instantaneous. The Royal
Navy had a significant number of ships in the area, including the aircraft
carrier HMS Glorious. These vessels became active in supporting the Norwegians
almost immediately. An expeditionary force with both British & French
troops was dispatched within days – the first British troops landing in Norway
on 12 Apr 40 with the main force arriving in the Trondheim area 5 days later.
By the 24 Apr No 263 Sqn RAF (Gladiators) had set up a base on a frozen lake. The
short campaign in Norway can be read about elsewhere. The few things I’ve
mentioned are to illustrate the major reallocation of resources sometimes
required when the enemy does the unexpected.
was building RAF Skaw, a Chain Home radar at Lamba Ness, but that too was
nowhere near completion – the first operations crew not arriving on site until
Nov ‘40. It was decided that radar cover to the north and east of Scapa &
Sullom was essential and that it must be provided quickly. It was also a
possibility that the planners wanted a radar in the area to help cover the
expeditionary force resupply and routine surveillance of aircraft movements
associated with it.
radar was still in its infancy but its potential had been recognised by all 3
services. Equipment was in short supply and technological developments were
rapid. However, the need for “transportable” radar had been recognised and the
RAF had orders placed for 2 sets of equipment.
This new situation was deemed important enough for the provision of an
extra transportable radar and so, on 11 Apr 40, the decision to form Number 3
Transportable Radio Unit (3 TRU) was taken.
equipment was gathered, probably some of it originally destined for use as Army
gun-laying radar, and the personnel (mainly inexperienced), allocated. In the wartime conditions in the first half
of 1940 it is almost unbelievable that a unit conceived on 11 Apr 40 could be
put together in the south of England, heavy (highly classified) equipment located
and assembled, then it & 62 servicemen transported to Unst in less than 4
equipment provided for 3 TRU was similar to what we now call an AMES 9 Mk1
radar system. The radar would have operated on a frequency of about 43 MHz
(wavelength about 7 metres) and a peak power of around 300Kw, provided by the
Units own 2 Lister generators. The
picture below (kindly provided by Bob Jenner) gives a good idea of the layout
and type of vehicles involved.
personnel had varied backgrounds – there were 2 Volunteer Reserve Officers and
60 other ranks. Squadron Leader Mike Dean MBE has provided a complete nominal
role of the unit which I have attached as Note 1. to this section. The
Commanding Officer was Flight Lieutenant Len Pittendrigh, who had a significant
role in a number of WWII radar establishments. This was his second RAF radar
unit, having served in Suffolk before being put in charge of 3 TRU. The picture
below is from after his time on Unst (I notice he has been promoted to Squadron
which had been surveyed for the unit on Unst, not far from the Baltasound pier,
proved to be pretty useless with radar cover largely obscured by high ground –
for those of you who know the area – the Heogs & the Keen of Hamar were in
the way. Pittendrigh did the only sensible thing an experienced radar man would
do – he decided to head for the nearest suitable high ground and hence the unit
was erected on the Keen of Hamar. Theoretically, at about 300ft (89m), there
should have been good radar coverage to the east & north-east in particular.
There were problems in getting the equipment up the hill to the site – some of
the zig zag tracks of the vehicles can still be seen. Once all the components
were in position there were further problems. All of the radio equipment worked
on batteries and it was discovered that the Coventry Climax powered battery
charger had been damaged. Without easy
access to spares it took the CO a number of days to find a solution and even
longer to make contact with Sumburgh for the first time. It took all hands to
get the 70’ aerials erected and once up there were difficulties in earthing the
radar system due to the solid rock below the surface layer. These problems delayed
the start of radar operations until 28 May. Once operational it was
found that the only serious screening was from 330° - 005°, where aircraft
below 1,000 feet were not seen.
has a very barren landscape, mainly what could be termed serpentine debris.
Today it is a reserve – the only known site of Edmonston's
In this area things grow slowly and 72 years on the
wheel ruts of 3 TRU’s trucks can still be seen:
On the ground there is still much evidence to
indicate that the “transportable” unit was there – but subsequently left. Local
folk tell me that the “L” shaped wall in the picture below was not there before
the unit arrived and that servicemen planned to grow vegetables on site –
perhaps the wall was erected to provide some shelter for crops or even
constructed at the behest of NCOs or Officers in an attempt to keep the troops
Close to this wall and spelled out in stone on the
surface are the letters “RAF” and “UNST” –
Two 70ft (21m) masts were erected; one for the
Transmitter and one for the Receiver, each of these masts were anchored to the
ground by four steel cables. Where the surface was suitable metal stakes may
have been used but where the ground was unsuitable, anchor points were
constructed – five of these points can still be seen:
There is something about wet cement that some people
can’t resist. A larger picture of the last anchor point is shown below and it
can be seen that the cement has the name of the unit “3 TRU 1940” and a skull
& crossbones picked out in serpentine. A swastika has also been inscribed
but for some reason it’s the wrong way round for the NAZI symbol – it is rather
surprising to see it and I am sure it was added without the CO’s knowledge.
Flight Lieutenant Pittendrigh was known to have worries about German
sympathizers or even saboteurs amongst his personnel - these matters were taken
very seriously early in the war.
The same anchor point has the names or initials of
many of the men who served on the Unit, as can be seen in the next set of pictures.
The name D Lamont is visible in the first - a look at Note 1 – the nominal roll
- shows an AC2 Lamont, DL – a Wireless Operator - on the strength in 1940.
Two further examples:-
EDR is almost certainly AC1 Rhodes, ED – a Radar Operator and
OH would probably be LAC Hare, OF – Radar Mechanic.
It had been the intention for the men to live under
canvas near the Baltasound Hall. The CO decided that more
weather-proof accommodation was needed and sent his Adjutant to look for
somewhere more suitable. It was discovered that the nearby Hotel Nord was
unoccupied (and unfurnished) - it was immediately requisitioned.
Most of the men and the Adjutant moved into this building, which
much later became Harry’s Shop & today is known as Ethel’s Shop. A small
number stayed in the homes of local folk. Some huts were erected on the Keen
for the use of on-duty personnel and the CO, Flight Lieutenant Pittendrigh, lived
on site. The next photo shows what is possibly part of the foundations of one
or more of these huts.
had brought rations from south, mainly dry and tinned, but the stock of
cigarettes and rum had been plundered by civilian dockers en route. The shop
nearest to the Nord Hotel, Millbrae, was soon emptied of provisions – Unst was
a “dry” island so the rum could not be replaced locally. Personnel soon found
that the boring diet could be supplemented with rabbits, fish & birds eggs.
the period the Radar was on the Keen there was a manned Coastguard lookout hut
close by. This was used throughout the war and indeed for long periods after
the war ended. The lookouts were local men (mainly ex WW1 mariners), working as Auxiliary Coastguards. They worked 6 hour shifts whatever the weather. There
must have been some interaction between them and the RAF personnel but, so far,
I have found no details of it. The photo below shows the base of a later Coastguard hut, built on the site of the WWII construction:
The following Google Earth Image shows the
layout of the site as it is today.
Operations. There is little data available
about how the unit performed after it was set-up and what there is suggests it
was not too successful. Reasons for this are not hard to find. What briefings
they had must have been very sparse – who were they to contact on arrival and
how, for example. Many of the men knew little about radar and the W/T operators
would have been slow – it takes a long time to be proficient with Morse code
and the necessity to encode messages would have delayed signal traffic
considerably. Aerials were erected for R/T and W/T but bad
interference was experienced. The communications aerials had to be re-erected
out of line of sight from the Radar Transmitter aerial to minimise this
problem. Working conditions for the Radar Operators would not pass any of
today’s ergonomic tests. The display was about 4 or 5 inches (10-12cm) in
diameter and at eye level.
Their work area would have been similar to
that shown in the next picture.
The whole environment must have been totally alien
to a large proportion of the men.
On 4 Jun 40 the Unit came under the
operational Control of HQ 60 Group. It is at this stage I think that some confusion
evolved regarding the history of the unit. I believe that is shortly after this
date that the Unit changed its name from 3 TRU to Number 203 Mobile Radio Unit
(MRU) – certainly it is 203 MRU when it left Unst.
were a few equipment problems; for example, it took 3 days to replace a W/T
valve –without it they would have been unable to pass information to higher
authority by normal routes. When the W/T was working it was not particularly
efficient, with reports being received late. An RDF (Radio Direction Finding)
Chain Operational Report dated 27 Jun 40 stated “Dr Bower, Scientific Observer, at Wick
Fighter Sector wrote:- “About noon today Unst reported that their W/T was now
serviceable so they presumably have the valve they require. It may interest you
to know that Unst were sending plots via Sumburgh and Donibristle (teleprinter)
and that these plots arrived anything up to 11 hours late.”
I don’t feel that the Unit can be held particularly responsible for
these late reports - I suspect it was more down to inexperience and a long-winded
communications system. Donibristle is in Fife and Wick is 200miles from Unst so
I’m not sure why this route was chosen or what could have been done at Wick if
the reports had been almost instantaneous.
For those with an interest in radio, the frequencies which were
allocated are in Note 2.
actual performance of the radar was fairly poor, another RDF report at the
beginning of Aug ’40 states that the average pickups were in the region of 20
miles and the maximum 40 miles. Once again we are talking about inexperienced
personnel operating unfamiliar equipment without expert advice readily
available. I’m sure that, given time, the performance would have improved.
A Squadron of Gloster Gladiators had been
based at Sumburgh (then a grass airfield), since early in 1940, but there were
no modern fighters based in Shetland until a Flight of Hurricane Mk 1’s was detached to Sumburgh (70 miles south of
the Keen of Hamar) in the middle of the year. I believe that a controller
accompanied this deployment but, with the poor ranges achieved from the Keen,
the radar cover would have been inadequate to produce effective results until
the performance of the Unit could be improved.
Royal Navy had a fully operational Coastal Defence Radar, based at Sumburgh
from Sep ’39 onwards, but its main purpose was to monitor surface movements to
the south. Later in the war this radar was used to control a number of interceptions of German aircraft.
Defence of the Unit
anecdotal evidence of a machine gun post just to the south-east of the radar
masts but I haven’t been able to find any sign of it. The area is actively
farmed, being outside the Nature Reserve and this has possibly destroyed any
evidence of it. The Unit had guards on duty, as can be seen from this copy of
Daily Routine Orders (DRO’s even in those days), dated 18 Jul 40 – the original
document was found by my wife’s grandfather, John Sutherland, who was one of
the Coastguard lookouts. According to the CO after the War, none of his men had
fired more than 3 rounds in training before their deployment to Unst.
another line of defence an armed trawler was stationed at Baltasound. Nowadays
an “armed trawler” can sound insignificant but the Royal Navy operated a number
of different classes of vessel which came into this category – many used to
bolster harbour defences. Between 1939 and 1945, for example, 197 “Isles” Class
armed trawlers were built for the RN and each of these vessels could carry a 12
pounder and 3 or 4 x 20mm Oerlikon AA guns. I don’t know what class of vessel
was deployed to Baltasound but I’m sure that the airmen were glad of its
presence. Initially communications between the trawler
and the Unit were visual – a mast especially for this purpose being erected on
the Keen and, in darkness, a signal lamp was used. The mast & signal lamp
would have been used for passing air raid warnings.
extremis, the sensitive equipment had been rigged with explosive and could have
been destroyed had the Germans landed on the island. Radar was highly
classified and the thought of it falling into enemy hands was of great concern.
A further indication of how Shetland was considered to be in the front line at
this stage in the war can be seen at RAF Scatsa. Scatsa, the most northerly RAF
airfield in UK, was built near Sullom Voe specifically for fighter aircraft to
provide cover for the flying boat base. The first 3,600 ft runway was completed
in Apr ’40 but no fighters based there at the time the radar was on the Keen of
Hamar. It was the only airfield in Scotland built with pipe mines laid at 50 yd
intervals along the runway and taxi-ways. These mines would have been used to
destroy the facilities should the Germans invade Shetland – the threat was
considered that seriously.
Visitors and the Local
were official visits to the site during the short life of the Unit. Certainly a
Group Captain and an Admiral arrived on Unst for separate formal visits – both
by Supermarine Walrus Amphibians from Sullom Voe - landing at Baltasound. I believe these aircraft were operated by No 700 Sqn Fleet Air Arm. Their
arrival, other than the disruption to normal life, would have had little
operational effect on the personnel on the Keen. Fortunately AES4 on Saxa Vord
and RAF Skaw on Lamba Ness were under construction, so there were other things
for them to do.
effect of the Unit on the local population is not recorded officially but there
are many anecdotes/stories and some of them have been recounted by my late
mother-in-law Lexie McMeechan (Sutherland as she then was). Lexie would have been 17 when the Unit landed
and she lived about 200yds from the pier and less than a mile from the site on
the Keen of Hamar. A few of the stories are summarised below.
the Unit landed at Baltasound the Unst folk, who were more used to seeing dark
blue naval uniforms, saw light blue uniforms with eagle badges. They thought it
was a German landing force and made themselves scarce! Flight Lieutenant Pittendrigh
expressed surprise at the time that no locals appeared at the scene of the
landing to see what was going on.
a local asked one of the airmen how they kept warm in their huts on the Keen
without range or a peat fire. When the airman said he had an “electric” fire
& tried to explain how it worked there was disbelief and suspicion that someone’s
leg was being pulled (no mains electricity on Unst until more than 15 yrs
Sullom Voe, with its flying boats, was a very active RAF Unit at this stage of
the War. It had a very credible station band and it was decided to send the
musicians up to Unst to hold a Dance in the Baltasound Hall. The musicians duly
arrived by sea at Baltasound on 3 Jul 40 and the dance took place that night.
The local population had a fairly high percentage of females – many of the men
were away with the Services, Merchant Navy or fishing. The isles were used to
dances going on into the night, weddings and significant events being
celebrated – one would think it was the ideal situation for the young
servicemen. However, Unst had no mains power so the music people were used to
came from a fiddle or two, possibly an accordion & maybe a piano in the
hall. The ladies only knew reels and jigs etc – the Band played foxtrots &
tangos etc – very little dancing took place but perhaps there was some
On 1 Aug 40 the Unit received a signal which said “Close down. Prepare to embark by August
This message took personnel by surprise and Flight Lieutenant
Pittendrigh refused to take action on it until he had sought confirmation.
After much hard work the Unit had been operational for just a few weeks and was
beginning to fulfil the role for which it had been deployed.
After 3 months on the island and even less time operational, the Unit
was shut-down – why? There are a number
of theories – the first involves the threat of invasion and the compromise of
theory that the Germans might land on Unst and capture this sensitive equipment
is highly attractive – the allied raid on Bruneval early in 1942, when secret German
radar equipment was seized, shows what might have been accomplished.
Personally, I don’t subscribe to this idea – the construction of AES4 on Saxa
Vord and the building of RAF Skaw continued. Many knowledgeable radar personnel
were left on Unst after the Unit departed – people and equipment just as
valuable to a German raiding party. Besides,
the naval Coastal Defence U boat radars (AES2 & AES3) on Fair Isle were
left in situ, despite the fact that they were probably just as vulnerable to
possibility, if the Unit had been deployed to help cover the resupply of the
allied expeditionary force in Norway, then that mission was complete. The British/French
force was withdrawn from Norway early in June, just after the Norwegian
theory I give most credence to is that based on a change in the perceived
threat. On 10 May 40 Germany invaded France and the Low Countries and met with
quick success, advancing very rapidly. The evacuation at Dunkirk took place
between 26 May and 4 Jun 40. Once again the main threat would appear to be to
the Home Counties – perhaps the army wanted the gun-laying equipment or perhaps
the now relatively experienced radar personnel would have been of better use on
radar sites further south. To put it in perspective – the Battle of Britain had
entered its first phase and radar was playing an important role. The RAF and
MOD recognise 10 Jul 40 as the start of the battle with the onset of the
“Kanalkampf” – the Luftwaffe attacking coastal shipping and its naval escorts
in the English Channel. The Germans achieved much success, sinking a number of
vessels including several destroyers. Perhaps the planners decided that experienced
radar personnel would be of better use elsewhere!
it be possible that the politicians and the military believed that the defence
of the Home Counties was more important than the defence of the Northern Isles?
leaving Unst the Unit was disbanded.
What did 3TRU/203MRU Achieve?
It would be simple
to say that the deployment to Unst was a waste of resources at the time of a
major threat to the country. That would be simple – but untrue!
Radar was new and the thought of a transportable radar unit was an important,
but largely untried, concept. The Unit was quickly formed and moved fairly
rapidly to its operational location. Yes, not everything went well, but the
experience of the operation was invaluable to future “mobile” and static
radars. The siting problems, the
communication problems, the command problems etc – there was a steep learning
curve which helped later operations. The men in this deployment were largely
untrained when they arrived but, when the Unit was disbanded, they were posted
to other radar units with invaluable experience. No one left Unst under the
cloud of failure – they were welcomed back onto mainland UK as “experienced
Pittendrigh went on to promotion and to play a significant role in the WWII
radar story. Amongst other postings he commanded the CH site at RAF Worth
Matravers and, when he was at Malvern, he worked on the identification and
location of enemy jamming sites. His immediate superior in Shetland Group
Captain Croke, the CO of the flying boat
station at Sullom Voe, wrote in Aug 40 to record his thanks. The letter
indicates his efforts on Unst had been appreciated. The fire referred to was in
the Nord Hotel and had been extinguished by Pittendrigh and his men just before
they left the island. The Dr Saxby, also referred to in the letter, was the
Unst GP – his son, Stephen, joined the RAF, served at Sullom Voe in WWII and
later worked as an MT Fitter in the RAF Saxa Vord MT Section.
A list of personnel deployed with the unit to Unst is given in Note 1
below. I have some information regarding 3 of the men. Wally Morton arrived on
Unst as an AC2 Radar Operator (under training); on closure of the Unit he was
posted to RAF Bawdsey. Later on in he was posted to other radar sites including
Hopton & Stoke Holy Cross. A picture of the late Wally Morton taken in
1940, just after he arrived at Bawdsey is below:
Two more of the airmen on this deployment, both
Wireless Operators, were subsequently sent to Uxbridge and almost immediately on
to the CH station at Ventnor on the Isle of Wight, (it was the height of the
Battle of Britain). Then, after a few months, to the Far East before the
Japanese invasion - they were LW Marchand and Pete Masters. They served on
early RDF sites jn Malaya and then, in Oct '41, they joined the Radio
Calibration Flight of 36 Sqn based at RAF Seletar in Singapore. The main roles
of the Flight were the checking of communications equipment and the calibration
of Chain Overseas Low (COL), RDF (radar) sites. To do this Marchand and Masters
flew in the back seats of the Flights two aircraft and, when engaged on RDF calibration,
were required to trail 200 yards of wire (to increase the size of the aircrafts
"echo"). The two aircraft allocated to the Flight were Vickers
Vildebeest. The following photo, from the Imperial War Museum, shows two
Vildebeest, belonging to 100 Sqn at Seletar before WWII started:
The Japanese began their invasion of Malaya just before
Pearl Harbour, in Dec 41, and the capitulation of Singapore followed quickly on
15 Feb 41. Both Vildebeest flew safely to Palembang in Sumatra on 31 Jan 41 and
then on to Batavia (Djakarta). Pete Masters was in one of the aircraft but I
have no record of who was in the other aircraft.
Note 1. Nominal Role 3TRU/203MRU
2. Radio Frequencies
2150 Kc/s W/T - Wick/Unst for Plotting
6470 Kc/s R/T Lerwick/Graven/Unst for Plotting (including contact with patrols
and to Naval Walrus aircraft stationed at Baltasound in emergency.
3085 Kc/s W/T - Graven/Unst for Admin or code
traffic (Graven was where the Admin & Domestic
Sites for RAF Sullom Voe were located)
Letters between Lexie McMeechan and Wally
The Keen of Hamar in 1940: Unst’s First Radar
Station by David Waters
& Laurie Bean of the RAF Butterworth & Penang Association
Taylor of the RAF Seletar Association
Scatsa Airfield (Revisited), Shetland by
AVIA 7/439 - RDF Chain Operational Reports
AVIA 7 - 709 GM E69 stamped AMRE 2 July 1940 - Report on Unst station No 3 TRU
The Unst Heritage Centre