Heritage 26 - Radar Hit at Pourville, Flight Sergeant Jack Nissenthall's Hazardous Mission
The target, the Germans' eyes and ears...
Undertaking the mission:
During one night in February, 1942 British paratroopers landed near the German radar station at Bruneval in north-western France. The aim was achieved in the snatch of vital components from the Wurzburg radar system. Why was this so important? Bruneval was a link in a chain that controlled anti-aircraft and night fighters that tracked and attacked British-based bombers on their way to industrial targets in Germany. Achieving this task enabled British technologists to work on counter-measures.
Another bid to snatch German radar elements was undertaken a little over six months later. It was eclipsed by, although part of, the greater assault on German installations at Dieppe as part of the British Naval Intelligence snatch, 'Operation Jubilee' (see HERITAGE 25). Although vital components could not be brought back, this raid was successful in spite of vigorous resistance. The aim of dismantling components from the Freya early warning system to be analysed may have been foiled, but the radar system was effectively 'shut down' temporarily. The on-site investigation by an RAF radar technician proved invaluable.
Whereas Wurzburg's ultra short-wavelength range was only 18.5 miles, the larger, less exact Freya with its longer wavelength could 'see' for 125 miles. It was able to detect Allied aircraft virtually from take-off. In tandem the two systems threatened the airborne offensive on Nazi Germany. Worse, it was learned that Freya had been improved and was to be the main anti-aircraft defence network. This would mean the need to step up investigation on Freya and if possible render it harmless.
In 1941 listening posts had intercepted signals emitted by a new high-powered Freya that was installed on a cliff between Dieppe and Pourville to the west. The site was earmarked to be a likely target, a convenient 'side-show' as part of a bigger raid. Success at Bruneval meant a further raid, at Pourville would be that much harder to achieve. The Germans had stepped up defences around their radar stations in the ensuing year. The chance to look at the equipment and remove components arose with 'Operation Jubilee'.
US and Soviet pressure meant that a second front would have to be opened soon. The overall aim of 'Jubilee' - according to British sources - was to sound out German coastal defences in France, to weigh the nature of German opposition in the defence of port installations. Another avenue was to reduce Luftwaffe capabilities in order to lessen the pressure on Soviet forces by 'leeching' German fighter forces. So a raid larger in scope than previous commando sorties was to be launched, under the 'umbrella' of assessing the necessary weight needed for a future invasion.
The target for 'Jubilee' needed to be a medium, fairly well defended port within air cover from southern England. Sixty-seven miles from England, Dieppe had been a staging point for Duke William's fleet in late September, 1066. It had since been occupied by Germans in the 1870-71 Franco-Prussian War. .
(In true BBC 'Blue Peter' form) here's one we did earlier...
The straightforward and believable plan first put forward was enlarged, with relatively greater risks. a final decision - based on incomplete, at best sketchy intelligence - was for a largely head-on attack on a well-defended port fronted by a gravel and pebble foreshore without initial air support and with minimal naval fire.
The operation was to include a large contingent of Canadian and smaller British, Free French and US Army units. Fifty US Army Rangers were to be the first Americans to land in Europe since the previous war with Germany. The objectives for 'Jubilee' would be the destruction of German installations (the Luftwaffe base at St Aubin was to be included), to take German prisoners for interrogation, take intelligence documents, capture moored invasion barges, release French Resistance prisoners and (hopefully) take components from Pourville's radar station.
This would be the biggest Allied sea-borne undertaking of the war so far, and approval was only given a week before its launch.
As at Bruneval the unit that attacked the Pourville site would include a radar specialist. At the age of 24 RAF Flight Sergeant Jack Nissenthall had volunteered for special missions in which his knowledge was needed. He was an electronics specialist who hailed from the East End of London, the son of a Jewish tailor who had migrated from Poland in 1912. Sgt Nissenthall had worked on radar from 1937.
Because he knew British radar secrets the Germans would be keen to learn, printed orders issued to the commando officer specified he was under no circumstances to fall into enemy hands. Ten riflemen of 'A' Company, Canadian 2nd Division South Saskatchewan Regiment would escort Nissenthall - with orders to shoot him if he failed to take the cyanide pill provided as a last resort.
Shortly before 4 am the vessels taking the Allied attack force ran into a German convoy of five ships. During the exchange of fire the smaller force shattered one of the commando landing craft before it in turn could be counter-attacked by the Polish destroyer 'Slazak'. Radio warnings from Admiralty failed to reach the 'Jubilee' force commander. Antenna damage kept the German escort ships from warning their shore-based colleagues, not that it was needed.
The Germans were forewarned by the 'Freya' operators who had detected the flottilla over twenty miles offshore. 'Jubilee' had been rumbled, the element of surprise lost. However when the radar section commander had passed the warnings onto his naval and army colleagues the naval commanders dismissed theirs as unlikely. The Wehrmacht commander did not. The German Kiegsmarine officers would rue their doubts when their shore battery fell to a commando attack during the ensuing engagement. Commando units would shut down the heavy artillery batteries east and west of the harbour mouth, so that tank-supported units could enter the town.
The South Saskatchewan landing craft made the shore on Green Beach below Pourville with Jack Nissenthall, whom they nick-named 'Spook'. Although he wore a helmet and battle fatigues, the radar specialist was armed only with a service revolver. He carried an RAF blue haversack stuffed with hand tools on his back on his back.
Dieppe, the overall plan
A warm welcome...
The Germans opened up as the Canadian landing craft grounded on the beach and dropped their front ramps. 'A' Company had to hurry up the western cliff slope to take on the radar site whilst 'C' Company took the village of Pourville itself. 'B' and 'D' Company moved inland to set up a blocking position to keep the enemy at bay. Another Canadian unit, the Queen's Own Cameron Highlanders landed a half hour later to hasten inland and attack the airfield, 3.5 miles away.
By the time Nissenthall's group had crossed the stony beach in the early dawn to the barbed wire topped sea wall they saw the Navy had left them almost 500 yards too far west. Instead of being at the base of the Freya cliff they faced the German-occupied village. With scaling ladders they climbed the eight foot high sea wall, crossed a promenade and went on into Pourville.
British aircraft provided cover for the Allied troops but until the Luftwaffe fighters showed the RAF's presence provided only moral support. Small arms fire and grenade explosions rent the air as the attackers made their way forward past the dead and dying. Tracing the shoreline through Pourville 'A' Company saw their path blocked at either end of a bridge that spanned the small River Scie. Beyond, a lane wound to the cliff where the road bent right to fillow the river. Atop the cliff Freya's antenna turned as it tracked and reported Allied aircraft.
But for the boat handler the company would have made landfall beyond the bridge and 'A' Company would already have been at the clifftop. A spray of bullets from the nearest pillbox left one Canadian after another sprawled on the road. During a break in the firing one of the soldiers sprinted forward and tossed a grenade through the firing slit. Then led by battalion and company commanders the South Saskatchewans passed over the bridge past the smoking pillbox and climbed the grassy slope under fire from above and right. Nissenthall and his minders followed the advancing soldiers, running between a stone church and a hotel to cross the bridge littered with the dead.
Shell bursts and small arms fire tracked the soldiers as they dodged the bullets up the largely wide-open hillside. There were only around two dozen men left of 'A' Company's original hundred. Of the ten that guarded Nissenthall only seven were still with him, three being 'walking wounded'. Later he remembered being deafened briefly when one of the men carrying mortar shells was hit and blown apart only yards away. Tossing smoke canisters, seeking the shelter of sparse cover the others eventually reached a place below the clifftop where they halted.
Left was a sheer chalk cliff face, rocks and shingle below. Ahead to the left of the pebble-strewn lane lay Freya, guarded by barbed wire. Riflemen in slit trenches and machine gun nests lay around it. Lying in a ditch lined by hedges a little below the radar site the company officer turned to Nissenthall, telling him, 'Well, there it is. Take it if you want it'.
The radar antenna's 180 degree horizontal arc motions told Nissenthall Freya was a target-oriented precision instrument, and that it was linked to the operator's cabin and block-house by a coaxial cable (unlike British radar with its 360 degree arc due to the use of electro-magnetic coupling). More detailed investigation could not be made through observation alone. 'A' Company was plainly unable to mount an assault to get closer. Help was needed but the company's portable radio no longer functioned. After a short discussion Nissenthall and two of his minders raced back to Pourville - now under steady fire from the Germans on the high ground on either side of the village. At Battalion the three men learned that shore-to-ship communication was almost non-existent. So, unable to train ship-borne guns to soften up Freya's defenders they gathered together a small mortar team. When a German shell put paid to that Nissenthall, unhurt but frustrated, ran the gauntlet back to the dwindling 'A' Company.
Desperate, Nissenthall made another escorted run to Pourville for reinforements. This time he succeeded in reaching 'A' Company with a mortar crew. Although he now had 'muscle' the men could get no closer. The sergeant would act on a suggestion made before leaving England, to whit if Freya's telephone landlines to its command post and decoding station were cut the radar crew would need to revert to radio communication. The radioed data could be monitored from England to provide the Allies with a reasonably accurate idea of the radar's capabilities. Nissenthall could see the critical telephone cables against the sky 120 feet away on the hilltop. The sergeant left cover on hands and knees and made for the tall grass, edging past a half-hidden machine gun nest. The earth shook with its continuous chatter. He reached a triple-post cable support a little way from Freya's perimeter, whose defences pointed to front and flanks but not to the rear. He removed and pocketed a pair of wire clippers from the haversack, then, wedging himself between two posts he worked his way to the top, fifteen feet from the ground, and cut the six outside communication cables. Rejoining his minders he could see they were in a bad way. He still wanted to take a closer look at Freya. Haggard and sweating, Nissenthall made his way back to Pourville to commandeer a tank to batter his way onto the radar site.
'A' Company's commander sent all seven remaining minders to escort his 'spook'. After over four hours of action the village was a mess. The ebbing tide revealed more corpses and abandoned equipment. Nissenthall talked a number Cameron Highlanders into going with his small group south-east along a road where the Churchill tanks were expected. On reaching the village of Petit-Appeville a mile away the soldiers stopped at crossroads to rest and wait. Soon they heard the clank of approaching tanks - only these were German, accompanied by troops on cycles. Nissenthall and the Canadians withdrew hastily, followed by bullets. more men fell on the way back to Pourville including another three of his minders.
Back to 'Blighty' under fire, yet cheerful
The Canadians fought a rearguard action prior to embarking. Slow-moving landing craft did what what they could to rescue survivors. Casualties mounted and their defence perimeter shrank. Still unhurt Nissenthall wondered about his chances of survival. He was under no circumstances to be taken prisoner. Escort destroyer, Hunt class HMS 'Brocklesby' moved inshore and lay down a smokescreen to hide the landing craft as they milled, taking on wounded and other survivors.
The destroyer's 4-inch guns opened up at a German position and part of a nearby chalk cliff blew away. An eerie stillness followed as other German guns stopped firing to avoid being blasted by 'Brocklesby's guns. Beleaguered Canadians gave a cheer and a number of them took advantage of the lull to sprint two hundred yards across open beach to the landing craft.
Nissenthall and his few remaining minders ran with them. Germans opened fire from houses nearby and from the high ground. Dropping their helmets and gear as they hurtled past the wounded, propped up against the sea wall, the men waded into the water. The sergeant and his one surviving minder dived below the waves to swim underwater for as long as they could. With their lungs bursting they came up and went on swimming for the landing craft, half hidden by the smoke screen. Their part-inflated Mae Wests allowed them to stop from time to time until they were rescued by a landing craft. As the craft emerged from the billowing smoke a pair of enemy fighters swooped. German 200 mm cannon shells hit the sides and the craft began to take in water. The battered craft sank slowly even as the tired soldiers were lifted out onto the destroyer. With HMS 'Brocklesby' taking the rear of the flottila on its way back to England German fighters attacked the vessels and over-whelmed the few remaining RAF Spitfires and Hurricanes.
Nissenthall disembarked at Newhaven late on August 19th. Next morning he travelled to London, dirty, dishevelled and unshaven, on a commuter train. He reported to the Air Ministry for a full de-briefing, buoyed that cutting the telephone cables had given the Allies valuable intelligence. British eavesdroppers listening to the German radio messages learned a lot about enemy aircraft control and the working of Freya. One outcome was the invention of jamming equipment, the task given to Nissenthall.
Due to the 'Act' (the Official Secrets Act) he was unable to discuss the action for twenty-five years. His next deployment was to the Middle East where he established a radar defence system. After the war he married, shortened his name to 'Nissen' and emigrated to South Africa.
Many years after WWII a company commander captured at Pourville was reunited with Nissen. The erstwhile captain told of his dismay at the order received, to kill him, and that he had put it out of his thoughts over the past twenty years. He admitted wondering if he had imagined being given the order.
'Would you have shot me?' was answered with 'Yes, probably I would have'. The reality was that as an RAF Flight Sergeant entrusted with Allied radar secrets he knew too much to be allowed to fall into enemy hands.
Dieppe Raid, 'Operation Jubilee', August 1942
Were you aware of 'Operation Jubilee', or had you heard of it?
© 2015 Alan R Lancaster