Born in Deutsch Eylau, Semrau grew up in the Weimar Republic and Nazi Germany. He joined the military service of the Luftwaffe in 1936. Following training, he was posted to Kampfgeschwader 30 (KG 30—30th Bomber Wing) and flew the Junkers Ju 88 as a bomber pilot during the Norwegian Campaign. In June 1940, Semrau transferred to the night fighter force where he was posted to I. Gruppe of Nachtjagdgeschwader 2 (NJG 2—2nd Night Fighter Wing). He claimed his first aerial victory on the night of 10/11 February 1941 and in December 1941, he was appointed squadron leader of 3. Staffel (3rd squadron) of NJG 2. In January 1944, he was given command of I. Gruppe and in November 1944 overall command of NJG 2. On 8 February 1945, Semrau and his crew were killed in action when they were shot down during a daytime maintenance flight by a RAF fighter aircraft. He was posthumously awarded the Knight's Cross of the Iron Cross with Oak Leaves on 17 April 1945.
World War II in Europe began on Friday 1 September 1939 when German forces invaded Poland. Following the outbreak of war, Semrau was posted to the 3. Staffel (3rd squadron) of the Küstenfliegergruppe 106, a maritime aviation group. He then served as Staffelkapitän (squadron leader) of 2. Staffel of Zerstörergeschwader 2 (ZG 2—2nd Destroyer Wing) flying the Messerschmitt Bf 109 D single engine fighter. In March 1940, he transferred to the (Zerstörergruppe) of Kampfgeschwader 30 (KG 30—30th Bomber Wing) where he learned to fly the Junkers Ju 88multirole combat aircraft.[5]
Night fighter career
Following the 1939 aerial Battle of the Heligoland Bight, Royal Air Force (RAF) attacks shifted to the cover of darkness, initiating the Defence of the Reich campaign.[6] By mid-1940, Generalmajor (Brigadier General) Josef Kammhuber had established a night air defense system dubbed the Kammhuber Line. It consisted of a series of control sectors equipped with radars and searchlights and an associated night fighter. Each sector named a Himmelbett (canopy bed) would direct the night fighter into visual range with target bombers. In 1941, the Luftwaffe started equipping night fighters with airborne radar such as the Lichtenstein radar. This airborne radar did not come into general use until early 1942.[7]
In July 1940, elements of (Z)/KG 30 were trained and converted to flying night fighter missions. This unit flew long-distance night fighter missions (Fernnachtjagd) referred to as intruder missions over England. These elements then became the II. Gruppe (2nd group) of the newly created Nachtjagdgeschwader 1 (NJG 1—1st Night Fighter Wing). On 11 September, II. Gruppe of NJG 1 was reassigned and became the I. Gruppe of Nachtjagdgeschwader 2 (NJG 2—2nd Night Fighter Wing) Kammhuber had created I. Gruppe of NJG 2 with the idea of utilizing the Ju 88 C-2 and Dornier Do 17 Z as an offensive weapon, flying long range intruder missions into British airspace, attacking RAF airfields. Until October 1941, I. Gruppe operated from the Gilze-Rijen Air Base,[8] and commanded by Major Karl Hülshoff.[9] Semrau was appointed Staffelkapitän of the 3. Staffel of NJG 2 on 22 December 1940.[1]
Semrau claimed two aerial victories on the night of 10/11 February 1941 over two Bristol Blenheim bombers shot down near Feltwell.[10] The Blenheim bombers belonged to No. 21 Squadron, the second of which was destroyed during the landing approach.[5] These were his first aerial victories, he had already claimed six aircraft destroyed on the ground flying destroyer missions.[10] The Blenheim bombers were returning from an attack on Hannover and included Blenheim Z5877 flown by Sergeant A. Chatterway who was killed in action.[11] He claimed his third aerial victory on the night of 7/8 May when he shot down a Vickers Wellington bomber near Nottingham.[12] This earned him the Iron Cross 2nd Class (Eisernes Kreuz zweiter Klasse) on 17 May.[4] The following night, Semrau claimed a Blenheim bomber shot down south of Grantham.[13]
Almost a month later, Semrau was awarded the Iron Cross 1st Class (Eisernes Kreuz erster Klasse) on 12 June.[4] That night, he was credited with the destruction of a Handley Page Halifax bomber near of Finningley, his fifth aerial victory.[13] On 7 July, Semrau shot down a Blenheim bomber over Wells.[14] On 18 July, he claimed another Blenheim bomber near Digby.[15] The aircraft shot down was however a Wellington bomber from No. 305 Polish Bomber Squadron.[5] Semrau claimed his last long range intruder aerial victory on the night of 20 September when he shot down a Handley Page Hampden bomber 7 kilometers (4.3 miles) northeast of Upper Heyford.[16] The aircraft was Hampden P5314 from No. 16 Operational Training Unit.[17]
Semrau received the German Cross in Gold (Deutsches Kreuz in Gold) on 24 April 1942 and was promoted to Hauptmann (captain) on 1 June.[4] On the night of 2/3 July, Semrau claimed a Wellington bomber shot down over North Africa. The Wellington probably belonged to No. 37 Squadron. On 4/5 July, he claimed another Wellington bomber which may have belonged to either No. 70 Squadron or No. 108 Squadron.[19] He again claimed an aerial victory on the night of 5/6 July which may have been Wellington bomber DV508 from No. 37 Squadron.[20] Semrau received the Knight's Cross of the Iron Cross (Ritterkreuz des Eisernen Kreuzes) after 160 combat missions and 14 aerial victories on 7 October 1942.[4]
Group commander
Semrau was appointed Gruppenkommandeur (group commander) of the III. Gruppe of NJG 2 in July 1943 which was based in the Netherlands.[9] This Gruppe was the former V. Gruppe of Nachtjagdgeschwader 6 (NJG 6—6th Night Fighter Wing) which was redesignated on 15 August 1943.[21] He claimed his only aerial victory with III. Gruppe on the night of 9 October over an unidentified four-engine bomber, on a mission to bomb Hanover, 35 kilometers (22 miles) west of Den Haag.[22] On 1 January 1944, Semrau succeeded MajorHeinrich Prinz zu Sayn-Wittgenstein of II. Gruppe of NJG 2.[9] On 1 May, he was promoted to Major (major).[4]
On the night of 28/29 June, the RAF attacked the marshalling yards at Blainville-sur-l'Eau and Metz with 230 bombers. The RAF lost eighteen Halifax bombers and two Avro Lancaster bombers in the attack, including four Halifax bombers claimed by Semrau. No. 102 Squadron lost five Halifax bombers, including NA502 shot down by Semrau.[23] On the night of 2/3 November, Bomber Command sent 992 bombers to Düsseldorf. In this attack, the RAF lost eleven Halifax and eight Lancaster bombers.[24] That night, Semrau was credited with three aerial victories over unidentified four-engine bombers in the greater Ruhr area. These were his last claims with II. Gruppe of NJG 2.[25]
Wing commander and death
On 12 November 1944, Semrau was appointed Geschwaderkommodore (wing commander) of NJG 2, succeeding Günther Radusch. Command of II. Gruppe of NJG 2 was then passed to HauptmannHeinz-Horst Hißbach.[9] On the night of 6/7 January, the RAF attacked the German railroad junctions at Hanau and Neuss with over 600 bombers. Defending against this attack, Semrau claimed three Halifax bombers shot down, his last aerial victories.[26]
According to Spick, Semrau was credited with 46 nocturnal aerial victories claimed in an unknown number of combat missions.[29] Foreman, Parry and Mathews, authors of Luftwaffe Night Fighter Claims 1939 – 1945, researched the German Federal Archives and found records for 40 nocturnal victory claims.[30] Mathews and Foreman also published Luftwaffe Aces — Biographies and Victory Claims, listing Semrau with 39 claims. Two claims dated 28/29 January 1944 and 30/31 January 1944 respectively are not recorded in Luftwaffe Aces — Biographies and Victory Claims while one claim dated on 2 November 1944 is missing in Luftwaffe Night Fighter Claims 1939 – 1945.[31]
Victory claims were logged to a map-reference (PQ = Planquadrat), for example "PQ 05 Ost AD". The Luftwaffe grid map (Jägermeldenetz) covered all of Europe, western Russia and North Africa and was composed of rectangles measuring 15 minutes of latitude by 30 minutes of longitude, an area of about 360 square miles (930 km2). These sectors were then subdivided into 36 smaller units to give a location area 3 km × 4 km (1.9 mi × 2.5 mi) in size.[32]
Chronicle of aerial victories
This and the ! (exclamation mark) indicates aerial victories listed in Luftwaffe Night Fighter Claims 1939 – 1945 but not in Luftwaffe Aces — Biographies and Victory Claims.
This and the % (percent sign) indicates aerial victories listed in Luftwaffe Aces — Biographies and Victory Claims but not in Luftwaffe Night Fighter Claims 1939 – 1945.
^Flight training in the Luftwaffe progressed through the levels A1, A2 and B1, B2, referred to as A/B flight training. A training included theoretical and practical training in aerobatics, navigation, long-distance flights and dead-stick landings. The B courses included high-altitude flights, instrument flights, night landings and training to handle the aircraft in difficult situations. For pilots destined to fly multi-engine aircraft, the training was completed with the Luftwaffe Advanced Pilot's Certificate (Erweiterter Luftwaffen-Flugzeugführerschein), also known as the C-Certificate.[3]
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