Today’s Auction House Artefacts are this pair of Luftwaffe WW2 bombing maps centred on Edinburgh and Dundee. They are of a yellow hue to make reading under aircraft night lighting easier and were printed on plastic-coated fabric to avoid creases and allow the navigator to mark on them in a wax pencil. Ziele (targets) are marked in yellow and reflect shipyards, airfields, military and power stations; that ink may have been luminescent.
Water, rivers, roads, railways and forests are marked as obvious navigation markers. The maps date from 1941 and interestingly all the place names are in English probably because they were basically reprints of captured OS maps, or just ones that they had bought pre-war. The German Navy (OKM) at least translated descriptive words on their charts into German, although again they simply bought up a set of Admiralty charts and reprinted them.
I think this is the full list of targets included on the Edinburgh map (excepting the Forth bridge which I neglected to annotate). The only targets mapped on the Fife and Dundee map is the Tay Bridge, the docks and Caledon shipyard.
These maps segue quite nicely into something else I was looking up recently which is the WW2 anti aircraft defences around Edinburgh. The principle defence was the fighter squadrons stationed at airfields at RAF Turnhouse and Drem. These were the first British air defences to be tested in the war; on 16th October 1939 a Spitfire of 603 Squadron from Turnhouse piloted by Flt. Lt. Gifford shot down a Junkers 88 bomber, one of 12 that had attacked the Royal Navy anchorages on the Forth, north of Port Seton. This was the first German aircraft of the war brought down over Britain and one of the four crew, Obergefreiter Krämer, was killed in this action. Spitfires from 602 Squadron at Drem under Flight Lt. Pinkerton brought down another bomber off of Crail, with 3 of the 4 crew being killed. Fifteen sailors from HMS Mohawk were killed by a near miss bomb that showered the ship with splinters.
However the city was also defended by a protective ring of gun batteries around the city. This was a far cry from WW1 when Edinburgh and Leith were completely undefended when a Zeppelin air raid dropped 44 bombs and left 14 dead. There were 5 batteries around the city, plus a decoy. Although the one at Silverknowes may have been a decoy too, and the others weren’t always armed depending on the phase of the war. These were part of the wider Forth defences, with 13 further batteries along the Firth.
These batteries were of a standard design known as HAA (heavy anti-aircraft) and the structures of the one at Alnwickhill is still there underneath the horse paraphernalia. There were four 3.7″ guns (blue dots) in a half ring around a control bunker (white arrow) and two magazines (orange)
The guns were mounted in the centre of the protective concrete rings, which also provided lockers for ready use ammunition. The QF (quick firing) 3.7 inch AA gun could fire a 13kg shell to an effective height of about 25,000 feet and could make 10-20 rounds a minute, depending on how well the crews could keep up with loading.
The battery was controlled by a mechanical computer known as a “predictor”, which had various dials into which you could input parameters about the target and ambient conditions (measured or guessed). The guns then pointed themselves the right way, the crew just kept them loaded. This would be located in the central building marked by the white arrow.
The shells were timed to explode around the target, there was a special machine on the gun that adjusted a clockwork timer on the fuse with the correct range just before the shell was loaded, again controlled by the predictor. The shells fired by the gun were not expected to hit their target, rather they had a mechanical timers that was set so that they should explode in the vicinity of their target, hopefully showering it with fragments and damaging or destroying it. There was a special machine on the gun that adjusted a clockwork timer on the fuse on the front of the shell with the correct settings just before it was loaded, again controlled by the predictor.
Despite this mechanical sophistication, getting a shell remotely close to a manoeuvring target as tiny as an aeroplane that is flying at 10 to 20,000 feet altitude at hundreds of miles per hour is a monumentally complicated mathematical problem. It was calculated that it would take 41 thousand rounds fired from 3.7″ guns to bring down a single aeroplane! To put this into context, the five batteries of 4 guns around Edinburgh could fire up to 320 rounds per minute at best performance. If you could keep that up without running out of ammunition, it would take 2.2 hours to bring down a plane which by then was halfway back to Germany…
What was needed was better input data to improve the chances. This is where radar came in, specifically GL or Gun Laying radar, which could provide accurate range up to 50m, and less accurate information on bearing and elevation (which were visually easier to determine).
But there was a problem with these sets – they were even by the standards of the day quite primitive and used a long wavelength, which was interfered by the ground around it and caused false returns. The solution was to create calibration charts for every installation which would allow the false positive signals to be tuned out. But it was soon realised that the effort required to create these charts for every single gun battery would be monumental. Much head scratching ensued until someone came up with the simple but genius solution of calibrating the ground instead of the radar set. An enormous circle, 120 metres across, was to be flattened around the radar antennae in the centre, which was mounted on a raised platform. Around this was laid a gigantic wire mat of 2 inch mesh, suspended on a wooden frame at a height of 1.5m.
Each mat covered a 13,000m2 area and required 230 rolls of mesh, 4 feet wide by 50 yards (1.2x46m) long. They used 650 miles (1,050 km) of wire plus a further 10 miles (16km) in the supports. Such was the scale of and priority given to these mats that they consumed the nations entire supply of chicken wire (no, really!). This was still a huge effort, but it made the ground around the radar set a known electromagnetic entity and any interference it caused could be easily cancelled out in the radar receiver. These sets and their mats were present at all four of the active Edinburgh batteries. And this is exactly what we see the ghost of at the Alnwickhill battery.
The improvements brought about in training, organisation and radar reduced the number of rounds taken to bring down an aircraft by an order of magnitude, to 4,100, which was a more realistic 10-15 minutes of firing per kill. In mid 1944, most of the UK’s heavy anti-aircraft defences, including those around Edinburgh, were hastily redeployed to the south coast of England to counter V-1 flying bombs as part of “Operation Diver” (a Diver was the code name for a V-1, as it dived on its target). By this point, advances in radar, computing and the invention of proximity fuses (which automatically explode when near the target) brought the rounds required for a kill down another order of magnitude to about 100.
There are no remains of any kind left of the other 3 batteries, but the decoy site at Hilltown is still intact.
You can see Craigentinny and West Pilton clearly on the post war 1945 aerial photography, although Sighthill was already cleared away and and it’s obvious Silverknowes was most likely just a decoy site of earthworks and huts.
Interestingly on some versions of these photos, the battery locations were scratched out (even though these were post war) or in the case of Alnwickhill were neatly censored.
All the anti aircraft guns in Scotland (and Northern Ireland) were part of the 3rd Anti Aircraft Division of the Territorial Army, headquartered in Edinburgh.
The Forth defences were manned by 36th (Scottish) Anti-Aircraft Brigade, with regiments at Edinburgh (94th), Dunfermline (71st) and Inverness (101st) although as the war progressed the organisation changed, and importantly, “Mixed” units were introduced which included women of the Auxiliary Territorial Service (ATS).
The Edinburgh defences also included at least two “Z batteries”, at Craigentinny and Pilton, which were rather terrifying rocket launchers that deployed 500 feet cables on the end of parachutes with a grenade dangling at the other end, to try and snag enemy aircraft. The Z batteries were an emergency deployment to make up for a chronic lack of proper anti-aircraft weapons, and were rarely effective. They did make a proper good fireworks display though and could be manned by older members of the Home Guard as the rounds were much lighter.
As the war progressed, most of Edinburgh defences were mothballed and the guns moved to the South Coast and the manpower was released to join the invasion forces. Other, more mobile, parts of 3rd AA Division moved with the allied forces and fought in mainland Europe. They were briefly reconstituted after the war, but stood down again in 1948. The last known use was for testing Bloodhound anti-aircraft missiles by Ferrantis at East Pilton in the 1950s, seen here at Alnwickhill
There were also searchlights, to try and identify targets for the guns at night (a largely fruitless task). Until recently only record I’ve seen of these is in a single page of a Home Guard map in the south of the city, in the City Libraries collection
But I have recently acquired a little book that is an account of the Home Guard activities in the south of the city during the war and it has an illustration of two searchlights visible from the Braid Hills in the earliest days of the war (note the LDV armbands and lack of official uniform).
Edinburgh and Leith were mercifully spared most of the horrors of aerial bombing meted out to other cities during WW2. Altogether there were 21 civilian deaths and about 210 injuries in Edinburgh and Leith caused directly by aerial bombing during the war. At least 5 further deaths were recorded as being due to “war operations” when people had heart attacks brought about by the shock of experiencing an air raid. Further details can be read in the thread about the air raids on Edinburgh and Leith during WW2 and the civilian loss of life they caused.
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