AERIAL PHOTORECONNAISSANCE
Long before Operation Overlord was in planning, the RAF was routinely taking aerial photos of German-held Europe as part of normal intelligence collection to see what the enemy was up to. Below is Ouistreham, eastern end of the future Sword Beach, on 31 July 1942. We see the Caen Canal and locks and Orne River curving to the sea farther east. Lines drawn on the print indicate aircraft nadir – important for mapping.
There hasn’t been much bombing damage and there weren’t many defenses yet – most German military resources were going elsewhere at this point and the concept of stopping an invasion on the beaches was two years in the future.
Above is the future Omaha Beach on 18 August 1942, from the left my arrows show: Les Moulins Draw; Saint-Laurent/La Sapiniere Draw; Le Cavey/Colleville Draw; and La Revolution on the far right. Vierville Draw is off the left side of the frame. The scale of this imagery made it useful for mapping and as a ‘base line’ to gauge future activity, but was so small-scale it provided little Intelligence value on defenses.
Tide is partly out and the beach looks deceptively clear and inviting for invasion.
Below, mouth of the Orne and Caen Canal, 27 August 1942. A small defense position (probably anti-aircraft) seems to be installed at the upper arrow. It doesn’t appear that work has begun on the Merville Battery (lower arrow). Horsa Bridge is at lower left.
Once the landing area was tentatively identified, photo recce began to collect more frequently and more systematically. Missions had to be run carefully because undue emphasis on a given shore might give the enemy ideas and eliminate surprise. Starting in late 1943, the number of recce flights over Occupied France from increased dramatically. Some of this effort was hidden inside the intense and obvious recon hunt for German flying bomb launch sites.
Below is Les Moulins Draw; Omaha Beaches ‘Dog Red’ and ‘Easy Green’, at high tide on 14 January 1944. Note unoccupied artillery positions and personnel trenches atop the bluffs. Since the draw would naturally channel attackers, defenses were arranged accordingly. Strong concrete gun and machine-gun emplacements were built on either side of the draw mouth.
Shadows show a relatively low ridge/sea wall just beyond the high-water mark and gradually rising land inland to a substantial cliff (100–170’) blocking access to the flat, open fields beyond. A few natural breaks in the cliffs are shown by roads going inland from the beach. Those draws would have to be used to get vehicles up onto the flat, open ground where maneuver was possible. It was expected that each draw would be defended from the heights as well as below in the swale and buildings just beyond the beach.
Colleville Draw (on the left) to La Revolution Draw, Omaha Beaches ‘Easy Red’, ‘Fox Green’ and ‘Fox Red’ as they were on 14 January 1944. Paths up from the beaches skirt cliffs and easily defended high ground, making them a ‘shooting gallery’. Note how the Colleville Draw route is steep enough to force circling east to make the climb inland.
A tank trap (ditch wider than an armored vehicle tracks can span with sides too steep for the tank to climb) has been begun to further deny access to a negotiable slope leading to open ground inland and force vehicles into a ‘killing zone’ ranged by anti-tank weapons. Enlargement disclosed no other significant defenses under construction.
Ponte du Hoc showed considerable activity on 15 February 1944, the sort of photo interpreters like to analyze. A lot of dirt has been moved and five gray circles in a ‘V’ generally facing north suggest positions being created for large guns. Located ten miles east of Utah Beach and four miles west of Omaha Beach, long-range guns here would pose a significant threat to naval and troop ships supporting the beaches, to say nothing of potential fire on the beaches themselves. Even without guns, German observation from here would be a threat to the invasion.
At high tide there is almost no beach at this location.
Enlargement of the Ponte du hoc imagery provides a better look at early construction of at least five sites that could develop into bunkers. This could reasonably be assumed to be part of the chain of positions for large artillery that were strung about every 20 miles along the coast, but no details can yet be discerned. Measurement of the assumed gun positions ruled out the super heavy weapons, but they had sufficient diameter to house up to 155mm field artillery pieces. Lack of rail access to the site also ruled out larger weapons.
Vertical imagery was supplemented by obliques that showed the same areas from a different perspective. This is Houlgate, a typical Normandy seaside town eight miles east of the future Sword Beach, on 24 February 1944.
Many beach defenses at this time were still simply close-set posts that would be just under water at high tide to block or overturn landing craft.
Pointe du Hoc again, this time in a lower tide on 8 March 1944, showing the width of beach shingle below the 100 foot cliffs. Shadow shows formidable cliffs to east and west of the point with no beach to speak of and no nearby draws providing ready access to higher ground from the beach.
Note the five revetments at the far right – possible positions for light field artillery. One even appears occupied (the upper right). Breaking the existing farm field patterns indicates a military purpose. However, the lack of track activity leading to them is suspicious. Guns had to be towed into position by something, and that should leave tracks.
Enlargement of the 8 March Pointe du Hoc imagery shows there are now six probable gun emplacements, three nearing completion, none occupied. Well-developed trenches defend the site.
In three months this draw would be heavily defended – and Omaha Beach landing sites ‘Dog White’, ‘Dog Red’, and ‘Easy Green’.
Shadows show the nearly vertical cliffs at Les Moulins Draw, 8 March 1944. It’s low tide but reflected light has washed out most of the beach coverage. The draw now has trenches and firing positions on heights overlooking the town and anti-tank ditches to stop or canalize vehicles trying to get off the beach. Intelligence could reasonably assume that at least some of the buildings near the entrance of the draw have been converted to firing positions for machine guns and anti-tank weapons. Confirmation of that information would come from French sources on the ground.
Omaha Beach Saint-Laurent Draw (La Spiniere) on 8 March. It is tempting to call the four apparent revetments on high ground to the left possible artillery positions, but again the lack of tracks is troubling, so is the narrow access in each revetment (guns have to enter somehow). There are, however, new trench/firing positions immediately above the beach directly in line with the small road leading inland. A straight road up from the swale indicates a more gradual slope than some of the other draws, and the mouth of this one is also wider. There is considerable trench activity on flat land just above the high-water line.
Le Cavey/Colleville Draw to La Revolution (Omaha ‘Easy Red’ to ‘Fox Green’) on 8 March 1944. The largest initial landings, and heaviest casualties, would occur here.
The tank-trap blocking access inland has been extended since January and track activity indicates active improvement of defenses on the heights above the curving road.
Sword Beach (‘Queen White’, ‘Queen Red’, ‘Roger Green’), the left flank of the invasion, on 28 May 1944. Note bomb craters at lower right – clearly misses of some target nearer the coast.
Note the complete lack of trenches, anti-tank ditches, strong points or encampments in the countryside behind the coast.
Future ‘Queen Red’ beach. Enlargement shows German strong point (Widerstandsnest) WN 20 and the beach in front of it with two definite lines of off-shore obstacles about 100 yards out. This was the most formidable position on Sword Beach with eight 50mm anti-tank guns, four 75mm howitzers and one of the much feared 88mm anti-tank weapons. Trenches linking large beach houses show where they have been converted to defense positions for machine-guns and riflemen.
Only one other area on the 28 May photo was suspicious, showing moved earth near the beach and back up a wooded hill behind the coast road. Trenches were a definite sign of defensive improvements. This would be ‘Roger Green’ beach on 6 June.
Ouistreham on 28 May 1944. Sword landings ‘Roger White’ and ‘Roger Red’ (closest to the Orne mouth), would be here on D-Day. A new anti-tank ditch carved through the city was as destructive as a stick of bombs dropped earlier.
Below, enlargement shows development of bunkers and trenches for a strong point. This would be the east end of British 3rd Division landings. It is hard to identify bunkers and casemates because earth disturbed by bombing looks the same as new construction.
About 1,500 feet west of the Orne was another obvious strong point. Trenches call attention to the area and structures not aligned with the road system are immediately suspicious as gun positions. Future ‘Roger White’ landings would be here.
It was important to get a good look at beach defenses from all angles and all tidal situations. This 18 March 1944 RAF coverage was probably made with a forward oblique camera. I found it in retired files of the Office of Naval Intelligence.
These seven successive lines of vertical posts are unsophisticated: simple materials, easy and quick to install with local labor. The 6 June landings faced obstacles much more complex and effective.
A frame from a 14 April 1944 RAF run along the coast using an oblique camera. The tide is out to best show the extent of off-shore beach defenses.
More of the 14 April run. Photoreconnaissance aircraft had to make dangerous ‘dicing’3 missions like this from Pas-de-Calais to Cherbourg lest the real focus of collection activity in Normandy tip off the Germans as to the intended landing areas.
Dicing let planners see how beach obstacles were constructed and anchored; get a better look at bunkers, casemates and machine-gun nests facing the beaches; and see the beach exits from a different aspect.
In this case beach obstacles are a mix of wooden posts and concrete-frame pyramids (see next Chapter).
The low-flying ‘photo bird’ scared workmen using a pile driver to set posts in the beach. Behind the lines of vertical posts are the more effective ‘Czech Hedgehogs’.
At least eight men are shown. Two lie on the sand at right, two are running left. The rest are ‘bailing out’ from some sort of framework in the center.
Someone in HQ must have looked at the dicing imagery and said, ‘Great stuff. The lower the better’. On 19 May 1944 US 10th Photo Group (10PG) pilots took up the challenge and returned a series of dangerous ultra-low flights.
This USAAF 30 Squadron (10 Photo Group) F-5 flew low over the beaches at low tide with a 12″ focal-length Forward Oblique camera.
This is another example showing that there was no ‘standard’ beach. The same off-shore obstacles were used, but arrangements varied considerably. In this case a line of ramp obstacles form the outer-most defense, some appear to be topped with mines. Next came a line of posts, some also topped with mines. Those defenses fronted densely scattered, and more effective, pyramids and ‘Czech Hedgehogs’.
In full tide, all these would be underwater.
Slender posts in the foreground are curious. They appear to be for a light fence. My guess would be a line warning workers not to pass along the beach—perhaps because of mines buried in the sand.
Vierville, 19 May 1944. The nacelle tells us this is the right oblique camera (RO) of an F-5 (photo version of the P-38) heading east. Any lower and props would be kicking up water. Speed was too high and altitude too low for the IMC (image motion compensation) in vertical cameras to compensate and images would be blurred, so only right and left high oblique cameras could be used. As it is, objects close to the aircraft are out of focus. 10PG flew eleven of these low-altitude beach recon missions in May, losing two pilots.
Below, tide is out and enlargement shows the most deadly and effective beach obstacle, ‘Belgian Gates’. Randomly positioned well out from the shore and placed to be under water at high tide, the ‘Gates’ were sturdy and well anchored, making them capable of stopping, capsizing or ripping the bottom out of a landing craft.
‘Czech Hedgehogs’ and ramps at Les Moulins (Omaha Draw D3), 19 May 1944. Note the offshore defenses are situated well beyond the high-water mark. Dark or boarded up windows indicate most buildings were unoccupied—or being converted to firing positions.
This dicing coverage went on for 250 exposures on the RO and LO cameras. Six inch lenses were used. The sortie was far too low to use the vertical camera of the Tri-Metragon installation.
It is interesting to note the off-shore defenses at many other beaches are more primitive in construction and less dense than those at the Omaha beaches. Apparently the Germans identified Omaha as a likely landing site just as did the Allied planners in England so Omaha got the ‘full treatment’.
Enlargement of Les Moulins oblique coverage shows German activity indicated by freshly turned earth near the water. We can’t see the anti-tank ditch from this angle, nor can we see German strong points atop the bluffs on either side of the draw (apparently built between March and June).
Numbers above equate to things on the 8 March vertical photo below.
Identifying matching buildings or objects allowed views to be compared from different angles and helped planners understand what they were facing.
Above, work parties on the sands at low tide, Saint-Laurent, Omaha Draw E1, 19 May 1944. Ramps, a ‘gate’ variation and hedgehogs.
Below, enlargement shows the building unoccupied (you can see right through the upper floor). The ramp running up the hill may be a skid-way to get gravel to the site of casemates under construction on the heights.
When I finished with the RO (right oblique) and began to roll the LO on my light table I was astounded to see that, for at least part of the 19 May mission, the pilot had been flying inside the outer perimeter of beach defenses, making this (as far as I’ve seen) one of the outstanding, and most daring, ‘dicing’ sorties of the war. The aircraft shadow says it all.
I also discovered a surprise at the start of one of the rolls of film. On his way to France, the pilot spotted something small and curious on the otherwise open sea far below him. As good recce pilots will do, he flipped on a camera to catch it. Had he been shot down, and his film recovered, I wonder what the Germans would have concluded from an extreme enlargement showing one of the Phoenix artificial harbor segments under tow somewhere off southern England.
Allied Intelligence knew a lot about conditions in France from agents and high and low altitude aerial photoreconnaissance. Above is an undated, low-altitude oblique of 82nd Airborne objective; Sainte-Mere-Eglise. The well-known church and courtyard are upper left.
Above, Carentan from the same photo series, looking northeast.
Above, Cherbourg, from the same series but possibly taken before the war from higher ground or a taller building. Allied Intel was interested in the port in the background.
Every possible airborne landing site was covered by recon in the search for safe fields near tactical objectives. This is a broad, flat, dry area on the Vire River, near the Caen-Cherbourg rail line (seen at upper right). This is three miles south of Isigny sur Mer on 28 May 1944.
Those white dots show spoil from vertical posts, ‘Rommel Asparagus’, set out in rows to interrupt a glider landing.
German engineers apparently deemed the east side of the Vire too marshy for a glider landing.
OSS Agents photographed a typical ‘Asparagus’ field near Cherbourg after Allied troops controlled the land. Cheap and easily installed by local labor without elaborate equipment, some of the posts were topped with Teller Mines and trip-wires.
Taking a significant risk, the Allies laid on high altitude photo recon of Invasion Beaches on 4 June 1944, just one day before the scheduled invasion. This enlargement is the ditch-defended strong point at planned Utah Beach Tare Green’.
Farther east, named the ‘Redoubt’, this strong point defended beach ‘Uncle Red’, the center of planned Utah landings. Note trenches and firing positions immediately above the beach. Easily seen inland are swampy fields that wouldn’t support heavy vehicles. That made trafficable avenues away from the beaches all the more critical in Allied planning, thus the 82nd and 101st Airborne Division landings further inland to gain control of the few viable routes between the beaches and solid ground.
More 4 June 1944 Utah coverage, farther east. Currents swept many landing craft here and this became Utah Beach on 6 June. Enlargement shows extensive light defensive works (for riflemen and machine guns) but an easy gradient off the beach – and a serious lack of multiple routes inland. Success at Utah depended upon quickly securing that road.
3. A term dating from WWI when low altitude flights over enemy territory were referred to as ‘dicing with the Devil’.