Under an Iron Sky
The Royal Navy under Air Assault
Writing good historical fiction is, in this author's opinion, not so greatly different from writing non-fiction - doing both things well is contingent on research. When setting out to write The Eagle and the Empire, envisaging the aerial combat that would ensue after the launch of a Nazi invasion of southern England, I found myself entering a minefield in the world of alternate history - Operation SEALION is a particularly hated piece of 'what-iffery' in the counterfactual world, mainly because of the conviction of so many that it could never have happened.
In 1940 of course, the average person on London's streets would be delighted to hear that there was never any real prospect of invasion. To be clear - I don't believe that for a moment. But I wanted to understand the arguments on both sides, framed through the lens of the Royal Navy, which nowadays is often held up as the single factor that would have safeguarded against SEALION, regardless of the outcome in the air.
Therein lies the first problem - or rather oversight in my opinion - that some observers make. Hitler's famous directive made very clear that the sweeping of the RAF from the skies was a necessary prelude to invasion, and as history of course records, that is the reason why SEALION was ultimately canceled. But sweeping the RAF from the skies could have been very possible - the proper use of certain aircraft types such as the Bf 110 and Bf 109 in the roles they were intended for, rather than as escorts; the targeting of command and control centres, not just airfields; most importantly, a different outcome from the meeting in The Hague and the possibility of persuading Hitler not to switch the effort to London, but to stay the course.
You will, dear reader, no doubt have your own thoughts on those points and their feasibility, but if you will indulge me I'll proceed on the counterfactual assumption that the Luftwaffe succeed in gaining aerial superiority, perhaps even supremacy. Ah! - the detractors will now observe - that doesn't matter, because the Royal Navy would put paid to anything that survived conditions worse than Sea State One. But would they?
What evidence, if any, is there of how the Royal Navy might perform under the dangerous umbrella of enemy air superiority? Does not Control of the Air directly impact Control of the Sea?
To help explore this, I looked to the Norwegian Campaign.
Hitler was motivated to launch Operation Weserübung (Weser Exercise) by his fear that the Allies might occupy Norway to gain access to neutral Sweden’s extensive supplies of iron ore. In particular, the northerly port of Narvik remained ice free year-round and both the British and Germans desired to control it.
Weserübung would be history’s first joint offensive, coordinated by Army, Navy and Air Force commanders. It would also be the first direct confrontation of the war between British and German forces. In this analysis of the Royal Navy’s vulnerability to air attack, Weserübung is a rich source of evidence; the RN would put to sea in strength, but unprotected by a significant air umbrella, while the Third Reich fielded a more powerful Air Force but far weaker Navy.
German landings in Norway began on the 9th April 1940, and Britain’s naval forces responded that same day. In the afternoon, the Cruisers and Destroyers of Commander-in-Chief Home Fleet’s task force came under attack from Luftwaffe bombers.
Elements of the naval group were engaged continually between 1430 and 1800[1] by 47 Ju 88s of Kampfgeschwader (KG) 30 and 41 He 111s of KG 26.[2] There was no RAF or Fleet Air Arm protection present to oppose the Luftwaffe attacks.
The Cruisers Southampton and Glasgow suffered minor damage from bombs falling close to them. This is an important point - a direct hit was not necessary to mortally wound a vessel, in the same sense that a depth charge could fatally damage a submarine without making contact with its hull.
The only outright loss was the Destroyer Gurkha. After breaking away to seek a better defensive position, she was heavily damaged and later sank. Despite the warships under command of Admiral Geoffrey Layton, which included the Gurkha, expending some 40% of their stocks of 4 inch ammunition, German records show that only two Ju-88s failed to return from the attacks.[3] For either side this could have been judged as a less than decisive engagement, however a catastrophic loss for the Royal Navy that would have translated into a decisive blow for the Luftwaffe was in fact only narrowly avoided.
During the engagement the battleship HMS Rodney, flagship of the Home Fleet and with the C-in-C aboard, was struck by a large armour-piercing bomb released by a Ju 88 making a diving attack. Rodney’s Gunnery Officer, Lieutenant Commander John Boord, recalled the moment the ship was struck:
“It landed on the boat deck and we were extremely fortunate because it was a big bomb, and on the boat deck was the 4.7 inch anti-aircraft battery and each gun, three each side, had one armoured ready-use locker and two un-armoured ready-use locker.” (Ballantyne, 2008)
HMS Rodney
Had the bomb struck one of these un-armoured lockers, the result could have been disastrous. In fact there was an even more serious danger, as recalled by Leading Seaman Len Walters, who had been instructed by his Warrant Officer to leave an armoured hatch open:[4]
“I worked the chains to open the hatch and, as he clambered up the ladder he told me to leave the hatch open, as he would be back soon. While he was away, we were hit by the bomb… Had it exploded, the Rodney could well have been another Hood,[5] as the open hatch invited the flash to possibly reach the Shell Room and the Magazine below.” (Ballantyne, 2008)
By good fortune the bomb had broken up on impact, separating the detonator from the body. The testimonies of Boord and Walters demonstrate clearly that the result could have been far worse.
Rodney’s lucky escape was not lost on the C-in-C Home Fleet, Admiral Charles Forbes, who decided that the fleet could not operate without air superiority, and therefore the battle in the waters of southern Norway would be prosecuted by submarine forces only.[6] This conclusion was also noted later where the Naval Staff History records:
“After the air attack on the Home Fleet in the first afternoon of the campaign, it was speedily recognised - at least in the Fleet - that ships could not operate with a reasonable chance of success in proximity to shore bases operating air forces virtually unopposed in the air.” (Brown, 2004)
A fairly uncompromising assessment from the C-in-C Home Fleet who, more than any other Officer, arguably understood the capabilities of the Royal Navy to defend the Homeland.
Two days later, on the 11th April, the Destroyer Eclipse came under air attack, suffering a direct hit that led to her engine room flooding. She was recovered to Lerwick, arriving on the 17th under tow of HMS Escort.[7] Eclipse would remain out of action until 10th August.[8]
HMS Eclipse
If near disaster for the Rodney was fuel for C-in-C Home Fleet’s fears of the effectiveness of air attack, then the experience of the heavy Cruiser Suffolk on the 17th April served as further confirmation.
In fact, Suffolk was undertaking an operation in the very area that Admiral Forbes had determined bore the greatest danger given German air superiority - the purpose of her mission (Operation Duck) was to disrupt that superiority through shelling of the aerodrome at Stavanger.[9]
In recognition of the risk, fighter escort had been arranged in cooperation with Coastal Command; however, these aircraft were unable to make contact with Suffolk and her group. Once again the Royal Navy were operating under what can only be described as German air supremacy; the Luftwaffe would again be unopposed in the air.
Suffolk was first attacked at 0825, and the assault would continue for six hours and forty-seven minutes.[10] She began withdrawing to the west in hopes of reaching the umbrella of British air cover. The Naval Staff History records:
“At 1037 the ship was hit by a heavy bomb, which caused very severe damage, put ‘X’ and ‘Y’ turrets out of action, reduced her speed to 18 knots and caused flooding to the extent of some 1,500 tons of water in 20 minutes.” (Brown, 2004)
It was not until 1415 that air cover reached the Suffolk.[11] Even then, air attacks from the Luftwaffe continued until 1512. A total of thirty-three attacks were recorded against the ship, originating from both high level and dive bomber aircraft.[12]
Of these attacks, twenty-three (70%) were recorded as impacting within 100 yards of HMS Suffolk. Thirteen (39%) achieved an accuracy within 50 yards, the majority of which (eight of these thirteen attacks), perhaps surprisingly, originated from high level rather than dive bombing attacks - an indication of the accuracy that could be achieved against a vessel manoeuvreing in open water.
The Suffolk was ultimately able to return to Scapa Flow, where she arrived on the 18th with her quarterdeck awash.[13] She was beached to prevent her from sinking, and repairs thereafter would take until March of 1941 to complete.[14]
This last point is significant. While the Luftwaffe had failed to sink the Suffolk, she had been so heavily damaged as to render her incapable of fighting until the following Spring - she was out of action for almost a year, and certainly would not have been available for action in the Channel in the Autumn of 1940. Blunting Britain's naval power was not only about sinking ships - putting them out of action for six months or more would place the Home Fleet in a precarious position at a critical time.
On the 19th April it was the turn of the supporting French squadron known as ‘Group Z’ to receive the attentions of Luftwaffe bombers. A Ju 88 of 5 Staffel KG 30 was able to hit the Cruiser Emile Bertin, however the bomb penetrated the ship without detonating;[15] another fortunate escape á la HMS Rodney. The Emile Bertin would be out of action until the 21st May, by which time the French would have more pressing concerns than the invasion of Norway.
Three days later, the sloop[16] HMS Pelican was hit by a bomb which blew off her stern[17]; she would not return to service until December.[18]
On the 24th April a second Cruiser, the Curacoa, was the subject of Luftwaffe bombing. She was seriously damaged and forced to return to Scapa Flow under escort of the sloop Flamingo.[19] The extent of the damage would see her out of action for five months.[20]
The Curacoa had provided relief for the sloop HMS Black Swan, who had been fulfilling the role of anti-aircraft guardship and now returned from the UK after replenishing her stocks of ammunition. On the 26th April the Black Swan herself came under continued air attack, and quickly depleted the precious ammunition with which she had been re-stocked. A diving attack delivered a bomb that passed right through the ship, penetrating the Wardroom and 4-inch magazine before exploding beneath the hull, causing sufficient damage for her to return to the UK and spend the next two months under repair.[21] The Luftwaffe had knocked out the anti-air picket with ease.
On the 30th April a third sloop, HMS Bittern, also employed in an anti-aircraft guardship role, came under dive bomber attack. She was so heavily damaged as to be abandoned, and later sunk by torpedo on Admiralty orders to prevent anti-submarine equipment from falling into enemy hands.[22]
By the end of April, the Home Fleet had lost seven warships from its ranks; Gurkha and Bittern destroyed, Suffolk, Eclipse, Pelican, Black Swan and Curacao all sufficiently damaged that they would take no further part in the Norwegian campaign. The Battleship Rodney, flagship of the Home Fleet and one of only two vessels of her class, had escaped being added to the list through fortune alone. What if, as could so easily have been the case, the Rodney had not survived? We will return to that question.
HMS Suffolk
HMS Bittern, soon after being struck
The following month would see further air attacks visited upon the Allied task force as both sides wrestled for control of the ice-free port of Narvik. Friday 3rd May saw particular success for the Luftwaffe’s anti-shipping efforts, as Ju 87 Stukas under the guidance of He 115s of Küstenfliegergruppe 506[23] sank the French Destroyer Bison and the British Destroyer Afridi,[24] the latter unfortunately after taking aboard soldiers and sailors rescued from the stricken Bison.
A further victim of air attack was claimed the following day when the Polish Destroyer Grom was sunk.[25] Three days later on the 7th May, the British Cruiser Aurora was attacked and damaged, two of her 6-inch turrets being disabled.[26]
The Luftwaffe would succeed in sinking another British Cruiser before the end of May; the Curlew, on the 26th, the same day that the Dunkirk evacuation would begin. Significantly, HMS Curlew carried aircraft warning radar equipment,[27] and this valuable defensive asset was lost to the task force. Yet another Cruiser, the Cairo, would be sufficiently damaged as to have to withdraw, remaining under repair until rejoining the Home Fleet in August.[28]
By the end of the month the United Kingdom had lost the battle to control Norway, and the British Expeditionary Force were being rescued from the French Channel coast. The Kriegsmarine had certainly been given a bloody nose, decimating the strength of their Destroyer cadre, but the Royal Navy too had borne witness to the devastating impact of aerial attack upon surface forces when unprotected by Allied air cover.
In the face of German air superiority, the Royal Navy had lost the Destroyers Gurkha and Afridi, the Sloop Bittern and the Cruiser Curlew. More telling, as we have seen, were the number of warships which were so badly damaged that they could not continue to fight effectively, including a further three cruisers; the Suffolk, the Aurora and the Cairo.
HMS Aurora
Things could have been far worse had a single incident transpired differently. The lucky escape of the Rodney, flagship of the Home Fleet and a vessel whose complement numbered 1,361[29], must be considered a stark warning as to the dangers posed by Luftwaffe air attack.
Rodney’s demise would have been a devastating blow to both fighting strength and morale. If, as Leading Seaman Len Walters describes, the bomb had detonated and the flash had reached the magazine, it is entirely feasible that destruction on the scale of that which befell HMS Hood in 1941 could have followed. When the Hood was destroyed by a hit to her magazine, only three of the 1,418 sailors aboard survived.[30] Had C-in-C of the Home Fleet Admiral Forbes been killed, the Germans would have enjoyed a fantastic propaganda coup, and the potency of maritime air attack might have brought the obsolescence of the battleship forward by more than a year. Alternatively, had he survived, his view that “ships could not operate with a reasonable chance of success” would doubtless have hardened into an even starker assessment, surely influencing defensive strategy in the event of a German invasion under the cover of Luftwaffe air superiority.
And so the question remains as to whether, in the absence of friendly Control of the Air, the Royal Navy could have opposed the invasion forces in the Channel without suffering critical losses. Far more academically qualified historians than I have made their views clear in many published works, so for my part I will say only this - it seems far from a foregone conclusion that they would have been able to do so (ask Sir Charles Forbes), and in 1940 the population were right to fear invasion.
Thank you for reading and if you have your own thoughts that you would like to share, on this or any other related warbird topic, please do get in touch or join the debate on social media.
References:
1 David Brown, Naval Operations of the Campaign in Norway April-June 1940 (Abingdon, UK: Frank Cass, 2004), Location No. 1222.
2 Jürgen Rowher, Chronology of the War at Sea 1939–1945: The Naval History of World War Two (Third Revised ed). (Annapolis, Maryland: Naval Institute Press, 2005), p 16.
3 Brown, 2004, Location No. 1228.
4 Iain Ballantyne, Warships of the Royal Navy - HMS Rodney (Barnsley, UK: Pen & Sword Maritime, 2008), Location No. 3058.
5 HMS Hood sank in May 1941 during the Battle of the Denmark Strait, after a shell fired from the Bismarck pierced her armour plating and ignited the ship’s aft magazine. She exploded and sank in three minutes.
6 Geoffrey Mason, Service histories of Royal Navy Warships in World War 2, naval-history.net, (2005) accessed 29 November 2020, https://www.naval-history.net/xGM-Chrono-01BB-Rodney.htm
7 Brown, 2004, Location No. 1493.
8 Mason, 2020, https://www.naval-history.net/xGM-Chrono-10DD-21E-Eclipse.htm
9 Brown, 2004, Location No. 2356.
10 Brown, 2004, Location No. 2382.
11 Brown, 2004, Location No. 2389.
12 Brown, 2004, Location No. 5030.
13 Brown, 2004, Location No. 2389.
14 Mason, 2005, https://www.naval-history.net/xGM-Chrono-06CA-Suffolk.htm
15 Lawrence Paterson, Eagles over the Sea 1935-1942, A History of Luftwaffe Maritime Operations (Barnsley, UK: Seaforth Publishing, 2019), Location No. 3399.
16 The classification of sloop in 1940 referred to craft intended primarily for escort duties, armed for anti-air and anti-submarine duties.
17 Brown, 2004, Location No. 2307.
18 Mason, 2005, https://www.naval-history.net/xGM-Chrono-18SL-HMS_Pelican.htm
19 Brown, 2004, Location No. 2300.
20 Mason, 2005, https://www.naval-history.net/xGM-Chrono-06CL-Curacoa.htm
21 Mason, 2005, https://www.naval-history.net/xGM-Chrono-18SL-BlackSwan.htm
22 Mason, 2005, https://www.naval-history.net/xGM-Chrono-18SL-HMS_Bittern.htm
23 Paterson, 2019, Location No. 3421.
24 Brown, 2004, Location No. 3224.
25 Brown, 2004, Location No. 3667.
26 Mason, 2020, https://www.naval-history.net/xGM-Chrono-06CL-Aurora.htm
27 Mason, 2020, https://www.naval-history.net/xGM-Chrono-06CL-Curlew.htm
28 Mason, 2020, https://www.naval-history.net/xGM-Chrono-06CL-Cairo.htm
29 R. A. Burt, British Battleships, 1919–1939 (2nd ed.). (Annapolis, Maryland: Naval Institute Press 2012), p. 348.
30 Ballantyne, 2008, p. 278.