Ploudalmézeau, in Finistère (FR), played, during WWII, a secondary but still interesting role. In addition to the shock caused by the arrival of foreign troops and the upheaval of their lives due to their installation on the territory of the municipality, the French population was confronted with the inconveniences caused by the mutual coexistence and the German military needs associated with the control of the territory and the air space.

According to the witnesses of Mr. Yves Fourn and Mr. Yves Bégoc, a large German horse-drawn column arrived in Ploudalmézeau (Finistère) in 1940 ( Figure 1 ). The Saint Joseph primary school was requisitioned and the classrooms were scattered in several other places in the town.

In 1942, the fields at the site called Dirichou, were requisitioned. A camp was built consisting of three shacks: two shacks about forty meters long, one about twenty meters long. The camp was protected by a network of barbed wire. The Castel quarry, now disappeared, with an area of four hundred square meters was covered with a camouflage net supported by railway rails. The quarry serves as a stable for about a hundred horses.

The German officer commanding the Dirichou garrison occupies a room on the first floor of the house of the father of the future doctor Bleunvin. Every day a German soldier, excellent shooter, rifle slung over his shoulder, passed in front of the Mr. Fourn farm and practices shooting in the warren under the disapproving gaze of the paysans. The relations between the population and Germans were limited to the strict minimum. The discipline of the troop was reassuring.

Some evenings, the spectacle of the glowing sky above Brest, multi-coloured by tracer bullets of anti-fighter batteries and the incessant scanning of the searchlights, was fascinating. ( Farrant, 2013a , 2013b )

A German company, unit 43 903S, working for the Organization Todt (O. T.) was in Ploudalmézeau in February 1943. The name of this company is unknown. The unit was stationed at St Joseph School.

The O.T. was responsible for the construction of the Atlantic Wall. In Ploudalmézeau sector five defensive structures, coded Re 06 - Re 10, provided the defence of the coast, especially from the Pointe de Carn and Pointe de Kerdéniel. The bunkers were held by detachments of infantry companies present in the sector. Ploudalmézeau was part of the defensive sub-group St. Renan indicated as Re. (Floch, 2012)

Two-thirds of the ancient Place aux Chevaux, today De Gaulle place, in Ploudalmézeau, were requisitioned by the O. T. for manufacturing cement used for the construction of the Atlantic Wall. A wooden fence surrounded the square closing the area to the civilians. Anti-tank rails fixed to the ground were erected on the route de Brest, Doctor Riou road and near the park of the new mill.

According to Mr. Bégoc, in the spring 1943, German surveyors measured plots of Lézérouté. A few weeks later, the pastures of farmers Rouzic and Kermorgant of the Kervédel and Kereunou farms were requisitioned. The O.T. built bunkers and four concrete platforms for artillery pieces. At Ty-Illioc, a watchtower and two barracks were erected. In front of Mr. Bégoc farm at Lézérouté, four deep shelters supported by planks and railway rails called by the Germans stollen were dug, two shacks were placed to the north and south, a dependence of the farm served as kitchen, forge and storage.

Towards the end of 1943, a large contingent of the Vlassov army, formed by Soviet soldiers incorporated willingly or by force into the German Heer, occupied the coastal fortifications of Portsall port near Saint-Pabu. Their reputation was disastrous.

On 6^th August 1944, during the mass in Ploudalmézeau, the participants were advised to return home quickly. A Russian officer, physician at Lézérouté camp ( Figure 1 ), was killed by FFI (French forces of the interior) soldiers passing through the town centre. The partisan Gabriel Bizien was captured and transferred to the Lézérouté camp. After, atrocious tortures, he was shot in the neck.

On 7^th August, an agitation spread among the garrison. Confusion and panic spread among the soldiers. The Russians requisitioned carts, horses, farmers and destroyed the untransportable equipment. Sheds were set on fire, and two bunkers were destroyed. They evacuated Lézérouté and retreated towards Brest. A few days later, a reconnaissance patrol of FFI based in Trougart inspected the military installations of Dirichou. In the abandoned camp of Lézérouté a dead silence was present. The burning smell was everywhere and the ground was littered with debris.

Around 11^th or 12^th August 1944, the bells of the Ploudalmézeau church rang loudly, the 29^th US Infantry Division had liberated the town. American soldiers inspect the Lézérouté camp. The Americans set up a tent camp near Castel and occupied four plots of land to park their combat vehicles. Kilometres of transmission wires were laid out along the roads and paths. At the end of September 1944, after the end of the fighting in the Brest region, the Americans left Ploudalmézeau towards the East of France. (Farrant, 2013a, 2013b)

However, in addition to the Lézérouté camp, during WWII, near Ploudalmézeau, a Y-Peiler numbered FuSan 424 (Lippmann, 2021) was constructed for the guidance of the German day and night fighters.

The map Morlaix Airfield area Airfields and Ln facilities ( Figure 2 ) of 14^th August 1943 (Henoff, 2023) confirms the presence of this Y-Peiler and indicated it as Atlantik I Y UKW near Ploudalmézeau and near another station indicated as Poseidon. On the map, Atlantik I as well as Lgw-Anl near Dora are encircled in orange and indicated with a question mark.

Atlantik I should not be confused with the Funksendezentralen Atlantik in Guichen (Tomezzoli et al., 2014) .

According to Rhubarb Operations (1944) , FuSan 424 ( Figure 3 ) had “1.ii) Pin point 48˚31'28''N. 4˚40'10''W. Grid ref: 832156. 3.i). 1½ miles S. S. W of the centre of Pludalmézeau on high ground in open country immediately West of the main road S. to LANRIVOARE. 3.ii) Altitude 235 feet (~72 m) above the sea level. 4.i) The target consists of a single open wooden lattice tower, 60 feet (~18 m) high and tapering towards a 16 feet (~5 m) square platform at the top. Vulnerable points are the square cabin below and the cylindrical D/F room above the platform. 4.ii) About 300 yards (~274 m) to the N. W. of this tower and connected to it by underground cable is a semi-sunken building measuring 108' × 43' (~2.7 × 1 m). 100 yds. (~91 m) to the W. S. W of this building is the usual small transmitter hut with its 80 ft. (~24 m) high mast. 4.iii.) Hedge clearance has been carried out all around the site. There are personnel slit trenches between the sunken building and the transmitter hut and possibly a pair of light machine guns. There is no heavy Flak in the immediate neighbourhood. 4.iv) The layout and immediate surroundings are shown on A. C. I. U. Plan No. G.158. Neg No. 38912R” ( Figure 3 ).

In the text 108' × 43' appears wrong, probably 108 × 43 feet (33 × 13 m) was intended.

The remains of FuSan 424/Atlantik I were positioned around Ty Illéoc near the Lézérouté camp ( Figure 1 ).

The visits to the field took place on 13^th January 2024 and 6^th June 2024. The Atlantik I and Lézérouté camp identified components were the following ( Figures 4-12 ).

The Pylon A, near or inside the Lézérouté camp, had not a well-defined position, therefore, it was not possible to identify its possible rests if any. Normally (Felkin, 1944b) , it was 15 - 25 m in height and comprised a D/F (Direction/Finding) octagonal cabin with orientable aerial array at the top, a receiver aerial on one of the legs and a range-measuring cabin at the base hosting a range-measuring unit.

The semi-sunken building B had not a well-defined position, but probably it corresponds to one of the bunkers of the Lézérouté camp.

The semi-sunken building C (48˚31'36.05''N, 4˚40'11.43''W, height 69.87 m) has completely disappeared, at its place remains a surface used as rubble dump. A light machine gun position, disappeared, was close to it ( Figure 3 ).

The trench D disappeared, but an old paysan, cultivator in the area, remembered that it was deep about 1.5 m and it was covered to allow space for the cultivations.

The transmitter hut, the transmission mast, normally 24 m heigh, and the two light machine gun positions E (48˚31'36.05''N, 4˚40'22.55''W, h. 65.86 m) disappeared. The paysan did not remember their presence in the area.

A bunker 0 (48˚31'16.31''N, 4˚40'0.86''W, h. 68.28 m) on the board of the Ty Illéoc-Lézérouté road, completely covered by terrain and vegetation. Its type and preservation state were not possible to be determined.

A 5 × 6 m bunker 1 (48˚31'17.1''N, 4˚40'1.53''W, h. 68.89 m) on the board of the Ty Illéoc-Lézérouté road, covered by vegetation. Only two concrete corners were uncovered, therefore, its type and preservation state were not possible to be determined.

A 5.5 × 9 m bunker 2 (48˚31'16.72''N, 4˚40'1.96''W, h. 68.78 m) completely covered by vegetation, therefore, its type and preservation state were not possible to be determined.

A 5.5 × 5.5 bunker 3 (48˚31'16.85''N, 4˚40'2.78''W, h. 68.94 m) completely covered by vegetation, therefore, its type and preservation state were not possible to be determined.

A 7 × 7.5 m bunker 4 (48˚31'17.36''N, 4˚40'4.28''W, h. 69.76 m) completely covered by the vegetation, therefore, its type and preservation state were not possible to be determined. According to the paysan, it hosted a telephone post.

A 7 × 8.5 m bunker 5 (48˚31'15.73''N, 4˚40'2.45''W, h. 68.6 m) buried in the terrain and covered by vegetation. Only a concrete side and portions of the coverage emerged, therefore, its type and preservation state were not possible to be determined. On the coverage a 50 × 40 × 30 cm concrete block was visible.

A 9 × 10 m bunker 6 (48˚31'13.81''N, 4˚40'5.2''W, h. 68.39 m) completely covered by terrain and vegetation. An inclined portion of the North side hosted a chimney hole and an inclined portion of the East side presented the upper portion of the entrance. Its type and preservation state were not possible to be determined. The entrance made visible a niche on its right side and the bunker interior filled with terrain.

A 6.5 × 7 m bunker 7 (48˚31'13.33''N, 4˚40'6.5''W, h. 68.17 m) completely covered by terrain and vegetation, therefore, its type and preservation state were not possible to be determined.

A 5.5 × 4.5 m bunker or platform 8 (48˚31'13.85''N, 4˚40'6.39''W, h. 68.2 m) partially emerging from the terrain and covered by vegetation, therefore, its type and preservation state were not possible to be determined. One corner was moved outside and another, partially uncovered side, presented three metallic attachments for camouflage net and pebbles of the Ero Vili (Tomezzoli & Marzin, 2015) .

A 7.5 × 5 m bunker or platform 9 (48˚31'14.85''N, 4˚40'5.6''W, h. 68.67 m) partially emerging from the terrain and covered by vegetation, therefore, its type and preservation state were not possible to be determined. Only an uncovered concrete side portion was visible.

A 5.5 × 5.5 m bunker or platform 10 (48˚31'15.08''N, 4˚40'6.62''W, h. 68.7 m) partially emerging from the terrain and covered by terrain and vegetation, therefore, its type and preservation state were not possible to be determined. Two adjacent uncovered sides preserved the traces of the formwork boards typical of the German masonry. A metallic roll was present on the coverage.

A 6.5 × 5 m bunker or platform 11 (48˚31'15.61''N, 4˚40'5.55''W, h. 69.01 m) partially emerging from the terrain and covered by terrain and vegetation, therefore, its type and preservation state were not possible to be determined. An uncovered side preserved traces of the formwork boards.

A bunker 12 (48˚31'16.78''N, 4˚40'5.38''W, h. 69.6 m) completely covered by the terrain and vegetation of the embankment between Surfaces A-B, so that its type and preservation state were not possible to be determined. According to the paysan it hosted a water reservoir.

On both Surfaces A and B, no trace has been found of possible concrete support blocks of the legs of the Pylon A.

Jones (2009) tells the Y-system historical development, its fighter driving method and the countermeasure Domino by which the British arrived to impair its functioning.

Felkin (1944a) describes devices used in the Y-Peyler transmitter unit, the D/F equipment and the range-measuring unit.

Felkin (1944b) , after having resumed the Y-fighter interception control methods, observes that: “35. A ‘Y’ control station requires nine men per shift, or 27/30 men per 24 hours, for its operation […]. The personnel of the ‘Y’ control station is distributed as follows: Transmitter hut: One operator. D/F Cabin: D/F Operator and log-book keeper. Range-Measuring Cabin: A Supervisor, range-measurer and log-book keeper. Plotting Room: Plotter (friendly plots), plotter (enemy-plots) and plotting officer”.

The necessity to host the plotting room and the 27/30 men lodgements explains the relatively large dimensions (33 × 13 m) of the semi-sunken building C. This suggests that the Atlantik I personnel was not intended to be lodged at the Lézérouté camp.

Atlantik I is indicated with a yellow circle ( Figure 2 ) and the Unterstellungsverhältnis (Subordination relationship) shows on 14^th August 1943 no subordinate relationship. The orange circle and the question mark around Atlantik I, as well as around Lgw: Anl near Dora, probably indicated that, at said date, these stations were either in construction or not yet operational. Because it had to drive day and night fighters, Atlantik I was intended to be dependent from Luftwaffe.

It is possible that the information from Atlantik I were intended to be evaluated at the nearby German air control centre at the L 479 bunker of Saint-Pabu (Tomezzoli & Colliou, 2017, 2018) .

The position of Atlantik I near Ty Illéoc and Coat Huella, 20 km from Brest ( Figure 2 ) was probably intended as protection against allied air attacks on the Brest installations and submarine base.

The presence of a Russian physician officer and probably Russian soldiers of the Vlassov army at the Lézéruté camp let to think that it was dependent from the Heer. The types and the purposes of the Lézéruté camp bunkers 0 - 12 are not well-known, although certainly they hosted personnel lodgements and an electrical generator. Probably, the watchtower (mirador) and the four concrete platforms for artillery pieces, mentioned by Mr. Bégoc, correspond to the pylon A ( Figure 3 ) and bunkers 8 - 11 ( Figure 4 ).

The information provided by Rhubarb Operations (1944) ( Figure 3 ) and Felkin (1944a, 1944b) permitted me to proceed to a reconstruction ( Figure 13 ) of the possible vision of Atlantik I from Lézérouté camp.

The visits on the field permitted me to determine that all the components of Atlantik I are gone and that the bunkers of the Lézérouté camp are all at their place although mostly covered by terrain and vegetation and consequently unrecognizable. As usual in historical research, further issues remain to be solved: the possible operative state of Atlantik I reached after 20^th September 43, its possible subordinate relationship after that date, the type and the purpose of the Lézérouté camp bunkers or platforms. For the moment, the forgotten position in the countryside and the coverage by terrain and vegetation contribute to the bunker preservation, but a more certain legal status and cultural recovery for them would be desirable. However, it is hoped that this article can form the basis for further studies on Atlantik I and the Lézérouté camp.

I express my gratitude to Mr. Henoff for his help in identifying the position of Atlantik I and for the maps in Figure 2 and Figure 3 and to Mr. Döremberg for his information and explanations concerning the Y-Peiler systems.