This is an essay from last May. I am republishing it from behind the paywall in honor of two pilots I am helping to memorialize this week, including one who died in OP Tidal Wave. Please consider supporting this endeavor with a premium subscription.
Winston Churchill called Ploesti “the taproot of German might” and Stalin was of similar mind. The decision in Washington to target Ploesti was therefore always political, a gift to allies who had been engaged with German armies well before American armies could arrive to make a difference. These politics were practical, however, for the strategic value of the target was obvious to everyone involved. Ploesti (pronounced ploy-ESH-tee) had been the subject of international strategic attention for decades. Oil was first struck at Ploesti in 1857, two years before the first strike in Pennsylvania, and already “by 1914 Ploesti was coveted as an essential of machine warfare,” James Dugan and Carroll Stuart write in Ploesti: The Great Ground-Air Battle of 1 August 1943. German armies prolonged the Great War by capturing the city in 1916. Queen Maria of Romania then used the Ploesti oilfields for international leverage and to attract foreign investment capital during the interwar period.
Red Army bombers targeted Ploesti right after Hitler’s invasion of Russia, with more than fifty sorties launched against the city before Soviet fliers lost their Crimean bases in 1941. Beginning with three small night attacks the first week, however, these ineffective strikes “were undertaken with no strategic objective and were small and scattered in nature. They proved little more than nuisance raids,” Jay Stout explains in Fortress Ploesti: The Campaign to Destroy Hitler’s Oil Supply. Advised that Crete and Greece were indefensible, Churchill nevertheless expended resources to hold them anyway simply because British bombers had the range to strike Ploesti from bases there. Churchill disliked SOAPSUDS, the name the American Col. Jacob Smart gave his 1943 mission concept, choosing TIDALWAVE instead for what would become the blackest day in the history of American military aviation.
This would not be the end of the story, however. During 1944, US Gen. Carl Spaatz focused on the same target using new technologies and tactics. By the end of that campaign, the United States and Britain had launched “5,446 bomber sorties and 3,498 protective fighter sorties, spread over twenty-four missions and several months” against the Ploesti refineries, according to Stout. As a result, the Wehrmacht and the Luftwaffe were starved of fuel in the face of simultaneous allied advances, east and west. Tidal Wave had been justified as a plan to shorten the war by six months. Six months after the last American bomb fell on Ploesti, the war in Europe was over. If any part of the allied bombing campaign might be judged worthwhile, it must be this one.
Forgotten in the excitement of the more-famous Doolittle Raid on Tokyo in 1942, there was supposed to be a larger, subsequent bombing mission launched from bases in China. Japanese forces overran those airstrips, however, so the mission was re-tasked for Ploesti. Col. Harry A. Halverson led the first detachment of the 98th Bomb Group, named “Halpro,” earning his fame with a daring raid out of North Africa. Halverson chose to remove the ventral ball turrets of his B-24 Liberators, sacrificing some weight for speed and range, and ignored British pleas to avoid violating neutral Turkish airspace. No planes were lost and only two men suffered light wounds. However, the damage inflicted was just as light.
“Rather than inflicting a sharp, telling blow on the refineries at Ploesti, the American force groped blindly about the country, randomly dropping bombs on no worthwhile target,” Stout writes. “It was an embarrassing beginning to an effort that would ultimately be characterized by a precision and weight that was irresistible.” However, “the mission did demonstrate the long reach of the B-24 and the will of the Americans to use it. This was a lesson that was not lost on the Germans.”
Nevertheless, Halverson was awarded the Silver Star for this action in June 1942 and promoted to the next level of command. Under his successor Col. John R. Kane, the 98th Bomb Group, known as the Pyramiders, still flew B-24D Liberators painted in the livery colors Halverson chose, a desert khaki with a “lion yellow” underbelly, in the words of bedouin observers. Likewise, Halverson’s policy of rapid advancement, promoting all his 2nd lieutenants to 1st lieutenants as quickly as possible, continued under Kane. With the defeat of Rommel’s Africa Korps in Libya, the unit also moved 200 miles closer to Ploesti from its bases in Egypt. The 98th was to be one of five bomb groups assigned to OP Tidal Wave in 1943.
Ploesti stood unmolested by the allies for over a year. Lutfwaffe Col. Alfred Gerstenberg did not waste the time. Each refinery complex had been constructed by its own consortium: Astra Romana was an Anglo-Dutch concern, for example, while the Romana Americana complex had been built with American dollars. All of them had been nationalized in 1941, but their overseers were capitalists at core, so they objected to Gerstenberg’s plan for a single pipeline connecting the complexes. He overrode them anyway, ordering the construction. Set above ground, so that repairs would be easy, this pipeline turned out to be the single most important countermeasure to the allied bombs that would fall on Ploesti, as it allowed rapid movement of crude oil to working refinery units, past any damaged ones.
Gerstenberg’s second effective measure was concealing smoke. Indeed, Stout maintains that this may have been his most effective defensive technique, given the troubles that it gave American airmen trying to pick out targets at Ploesti. Missions had to be repeated for missing their mark. Small teams were posted to set off the smoke pots when the alarm was given. However, because they used chronosulfonic acid, a byproduct of the refineries being guarded, every critical hit to the infrastructure reduced this advantage. By the end of the allied campaign against Ploesti in 1944, smoke was only rising from the ruins.
Ploesti also called on German air power to defend it, consuming aircraft and pilots and radar systems and everything else that was needed elsewhere. Hitler had been reluctant to defend a point so deep inside Axis-held territory, but the 1942 Halpro raid convinced him of the necessity. As a result, by 1 August 1943, the target was well-defended, not only by Germans but Romanians flying a mix of fighters, both Romanian and German-built. They would take a great toll on the allied pilots. “If anything, the night defenses were even more closely coordinated than the daytime defenses,” Stout explains. As the Royal Air Force preferred night bombing, they suffered the highest losses in air-to-air combat during the four missions they conducted against Ploesti in 1944. Night fighters equipped with radar, guided by nine ground stations guiding the crews to intercept bomber “streams,” convinced Gen. Sir Arthur Harris, the RAF bomber commander, to curtail his participation in the campaign.
But in this sense, the campaign made itself easier over time. German Reichsminister of Armaments Albert Speer reported at the end of June 1944 that “the enemy has succeeded in increasing our losses of aviation gasoline up to 90 percent by June 22.” This put a severe crimp on pilot training, which already suffered from the loss of veteran pilots in combat. As a result, Speer’s factories were turning out record numbers of planes in 1944, but there were not enough trained fliers. Another difference between Tidal Wave and the later campaign was fighter air cover. American P-38 Lightnings and P-51 Mustangs equipped with drop tanks were not only meant to defend the bombers, but reduce the Lutfwaffe. Stout writes that Romania was unable to resist Red Army aviation in 1944, or stop Soviet invasion of the country, because the allied Ploesti campaign had ended the lives or careers of so many Romanian pilots.
Flak thus claimed the greatest number of American lives and planes, not just during OP Tidal Wave in 1943, but as an increasing proportion of losses during 1944. Germans doubled the number of antiaircraft guns at Ploesti from April to August that year. Gerstenberg’s best innovation was a train mounting flak guns that could be moved around the city. This was the “Q-train” that the Pyramiders and the 44th Bomb Group had the misfortune to run alongside on their approach to the target during Operation Tidal Wave. A unique battle took place as “the air gunners enfiladed the train and blew up the locomotive, but not before it had hit some ships so hard they would not get far beyond the target,” Dugan and Stewart write. The train worked so well that Gerstenberg replaced and improved it.
Germans defending the refineries held an electromagnetic advantage in 1943. A radar network provided early warning of inbound bomber formations and Wurzburg radar sets aimed flak at high-altitude targets. Avoiding radar to achieve surprise was a key design goal of both low-level missions American airmen launched against Ploesti, but neither operation escaped German notice. High-altitude attacks during 1944 made best use of new radar countermeasures. Among these was “Window,” the British codename for chaff, cut foil strips the bomber crew tossed out of the aircraft to confuse radar operators. The “Carpet” jammer system also proved “quite effective” against the Wurzburg radars. Germans countered with new multichannel radar sets, so the Americans placed jammers in every bomber to do distributed “barrage jamming” on all the channels they used. In the arms race which followed, Germans developed systems that utilized Doppler effects and frequency shifting to work through the jamming. However, these technologies could not be fielded fast enough, or in enough numbers, to cope with Luftwaffe losses.
Both sides relied on signals intelligence of the enemy. Ploesti’s defenders were first notified by the allied alert message as Operation Tidal Wave was taking off. German codebreakers had cracked the encryption and could read the warning to allied aircraft and ships to expect the large flight of American bombers over the Mediterranean. During 1944, on the other hand, Fifteenth Air Force put German linguists aboard their lead aircraft to eavesdrop on air defense radio traffic and give early warning of fighter attacks. Aware that Germans would use their own chatter against them, Operation Tidal Wave pilots observed strict radio silence instead of correcting navigational errors that disrupted the plan of attack. Indeed, ducking under the German radar coverage was the primary point of Smart’s approach.
Designed specifically for high-altitude bombing, the B-24 was not an obvious choice for a low-level attack mission. Notoriously hard on flight crews, the yoke was so difficult that pilot and co-pilot normally worked in shifts during formation flight to avoid fatigue. In the United States, Liberator pilots under training were actually forbidden to fly at low altitude because the plane was not designed for it. Now they were being asked to break the rules, give up any altitude cushion to deal with emergencies, and do this daredevil stunt at the monkey’s end of an exhausting seven hour formation flight.
The plan had obvious drawbacks. Navigation is harder at low level. While this tactic reduced the number of angles from which the bomber could be attacked, it also increased vulnerability to ground fire, including small arms fire. An unknown number of airmen, especially waist gunners, were killed or wounded by ground fire that would have never reached high altitude. Surviving reports show that bomber crewmen returned this fire with their own machine guns, justifying Dugan and Stewart’s title of a “ground-air battle” as opposed to a simple bombing mission.
Col. Jacob E. Smart, the staff advisor to Gen. Henry A. Arnold, was picked to come up with the mission plan for Ploesti. None of the airmen being asked to fly the mission was on his planning team. Like most Americans, he had no combat experience. Yet “the idea seemed to have everything,” Dugan and Stewart write, because it would be so unexpected. “It was a cunning psychological trick. Everyone, including the Germans, knew the American monomania for high-level attack by heavy bombers.”
An unprecedented low-level strike would permit the utmost precision bombing of the vital pinpoints in the refineries and score with the most explosives. It would spare civilians and raise American esteem among the subject peoples of fascism. It would reduce losses of men and planes by affording the flak gunners only low, fleeting targets.
Smart presented his proposal at the Trident Conference in Washington, DC in May 1943, when the United States and Great Britain planned the invasion of Sicily. British chief of air staff Sir Charles Portal thought it would subtract too many bombers from support operations against Sicily or the larger bombing campaign against Germany. He “also wondered aloud whether, if the mission failed to destroy enemy oil production in one blow, the Germans would not build up heavier defenses at Ploesti to cope with the succeeding attacks that would have to be made. Gen. George C. Marshall, the US chief of staff, thought that even “a fairly successful” operation would be justified by shortening the war. Explaining his idea to Winston Churchill, “lifelong lover of surprise raids,” in a private interview, Smart won the necessary political support. “It was one of the few instances in World War II in which the High Command handed down a major task to a theater commander without asking him if it was feasible,” Dugan and Stewart write. With too few bombers to hit every target, however, “the Allied chiefs had given Jacob Smart a strategic mandate with no known tactical solution.” High attrition of men and planes was taken for granted.
There was opposition. “Analysts were always telling Bomber Harris that huge single raids on pet Geman industries would shorten the war by six months,” Dugan and Stewart say. Upon learning of the plan, some of the men being asked to execute it expressed their misgivings. Col. Kane complained that “some idiot armchair warrior in Washington” had come up with the idea. Alfred Kalberer, leader of the Halpro mission, refused to have anything do with it, saying “this thing can’t work” and estimating 32 planes would be lost. He was relieved and sent home; his prediction was an underestimate of the eventual losses. Brig. Gen. Uzal G. Ent, commander of IX Bomber Command, even drew up a dissenting petition for the bomb group commanders to sign, but abandoned the effort rather than create disunity.
For Gen. Lewis Brereton “reportedly would brook no resistance to the plan and threatened to relieve any of this commanders who gave anything less than full support,” according to Stout. Low-level flight training began in both England and Libya. The mission was on. Believing they stood to shorten the war by half a year, many American airmen expressed an acceptance of the risks. Scheduled to fly on the mission, Gen. Ent even told Col. Kane that “if nobody comes back, the results will be worth the cost.” Last minute orders from Washington grounded Ent, deemed too valuable to be lost.
The plan was overreliant on surprise. Despite having no recent intelligence of the target, there was no reconnaissance mission for fear it would alert the defenders to what was coming. Smart’s mission intelligence annex admitted there “have been no recent reports to determine the antiaircraft defenses of the target” but assumed they would be positioned in expectation of a Soviet attack from the east rather than Americans coming over the Carpathian mountains, from the direction of Germany. Romanians, presumably with low morale, were expected to be manning the flak guns instead of Germans. A captured Romanian pilot disabused Army Air Corps intelligence of this impression just five days before the operation, informing them that the guns were indeed more numerous than understood — and manned by Germans. The mission went ahead, with every man briefed that “the heavy guns would be unable to direct accurate fire at low-flying formations because of their inability to follow fast-moving targets. The results would be nil. The target has been unmolested for years and is not expected to be alert.”
Smart seemed to have a point. Some B-24s made successful low-level attacks against tactical targets in the Italian theater of war before August 1943. Supporting the invasion of Sicily, “these actually were quite effective,” Stout writes. The five appointed bomb groups began practicing in the Libyan desert against dummy targets. Airmen wrote letters home, knowing their chances of never returning. Every man who flew that day received the Distinguished Flying Cross; 310 were dead, 108 captured, and 78 interned in neutral Turkey when fuel ran short. Five Medals of Honor were awarded, four posthumously, the most ever for any single action in the history of American military aviation. According to the newsreel, it was a smashing success.
Only one of the five main Ploesti facilities, the Creditul Minier refinery, was put out of action for the duration of the war. Although Gerstenberg’s pipeline helped production rebound quickly, the remaining refineries had to increase their own output to make up the difference. Although “the raid was considered by some critics to have been a sort of stunt,” Stout writes, “airplane for airplane, the attackers on this particular raid caused more damage than any other subsequent raid against Ploesti.” Germans were impressed by the “deep-level” attack. Romanians were impressed by the relative dearth of civilian casualties.
When the Allies returned in April 1944, however, they had less concern about ‘collateral damage,’ killing 4,000 civilians. The United States flew another 20 missions against Ploesti, the RAF four. Altogether, they lost nearly 1,000 air crew killed in action across 25 bombing missions, though none were as deadly as Tidal Wave.
Even those losses deserve some context. Every B-24 squadron that crossed the South Atlantic to North Africa experienced some number of planes lost between Natal, Brazil and Dakar, Senegal. For example, the 459th Bomb Group lost as many Liberators in transit as they did on their very worst mission. More than one pilot experienced simultaneous failure in all four engines and recovered their Liberator, but most of the pilots who had this experience probably did not survive it.
As the Tidal Wave planes neared Corfu, for example, a witness saw the Wingo-Wango suddenly “stagger, dipping down and nosing up in an ever-increasing movement, until its nose rose higher and higher into the air,” then “when virtually standing on its tail, Wingo-Wango slid over on her back, and slowly gaining speed, planed straight down and dove violently into the sea.” The pilot was experienced; the plane was brand-new. Some sort of mechanical failure seems the likely culprit, and we are left to wonder how many B-24s were lost in the same way.
No one bombed Ploesti between 1 August 1943 and 5 April 1944. This eight-month reprieve was not a product of the high losses. Gen. Carl Spaatz was eager to hit Ploesti, as well as every production site for petroleum, oil and lubricants (POL) in Nazi-held territory. However, Gen. Eisenhower, the Supreme Commander in Europe, was suspicious of the strategy and ordered Spaatz to focus on infrastructure, such as marshalling yards. Spaaz obliged by ordering an attack on the rail yards outside the Astra Romana refinery that somehow managed to badly damage the facility. During follow-up attacks on 15 and 24 April, “the bombers seemed unable to deliver all of their bombs on the designated transportation targets,” Stout writes. “Inexplicably, many of their bombs seemed to fall into major refineries. Results were immediate; German imports of petroleum products from Ploesti during April 1944 were only 56 percent of what they had been during March.” Eisenhower caught on and ordered a stop to the shenanigans, but Spaatz eventually won permission to execute his Oil Plan and carried it out with a vengeance.
Italian bases shortened the range. Pilots had developed best practices for fuel efficiency. The H2X ground radar set gave bombardiers a way to see through cloud cover and smoke. Yet the biggest difference was fighter cover. Drop tanks had extended the range of the P-51 Mustang. As a result, the bombing campaign in Europe had become a means to an end. Spaatz was choosing targets that the Lutwaffe would absolutely have to defend, including Ploesti, so that Axis fighters would attack the bombers, opening themselves to attack by the escorting fighters. This strategy had its first success in the “Big Week” of February 1944. During Operation Argument, more than 1,000 allied bombers escorted by 660 fighters carried out a series of missions over Germany. At great cost, the bombing campaign achieved air superiority over Europe.
Spaatz was finally free to send the Eighth and Fifteenth air forces against Ploesti in June 1944 and systematically reduced the refineries with prejudice. He also had the benefit of a much larger bomber fleet. The raid on 15 July involved more than 600 B-17s and B-24s, almost three times the size of the bomber force used in Tidal Wave; a combination of high-altitude bombing with electronic warfare and fighter escorts held bomber losses to just 6 percent. At that point, Romanian gasoline exports had been reduced by half since April.
Incredibly, the Americans tried one more low-level attack on Ploesti during this time. The Romana Americana refinery had somehow escaped serious damage thus far, and not for lack of effort. “A number of factors, including an especially effective smoke screen, had combined to protect it from more significant destruction,” Stout says. “As the largest and most productive of Ploesti plants, this situation was intolerable to Spaatz’s Oil Plan men; the Romana Americana refinery alone was producing nearly 15 percet of the total Axis petroleum supply.” This time, however, the mission would be carried out with twin engine P-38 Lightnings, and instead of bombing from low altitude, the attackers would zoom up at the last moment to act as dive bombers. Carried out on 10 June by two fighter groups, “it was the worst day in combat that either unit ever experienced,” Stout writes, as well as the blackest day the P-38 Lightning ever had.
Unaccustomed to the 1,000-lb bombs or the large external fuel tanks added to their planes for this mission, the pilots found their controls sluggish. Once again, a low-level approach failed to escape notice by German radar operators. Although half the American planes were to provide fighter cover to the other half, which had the bombing mission, Romanian IAR-80/81 and German FW-190 fighters “played havoc with the P-38s,” Stout says. Moreover, “dive-bombing was not something the P-38 fliers practiced often.” Another intense air-ground battle took place in a storm of small arms fire and flak. Nearly 30 percent of Lightnings and their pilots were lost, almost the same proportion as Tidal Wave, inflicting less damage than the mission planners had hoped.
It was also the fifth time the “resilient and vexing target” had been hit, Stout says. Determined to finish it off, on 24 June another 200 aircraft were sent against the Romana Americana refinery and other targets. Although the damage was once again less than hoped, this time 25 Axis fighters were destroyed, and Stout writes that “the Romanian units in particular took a beating.” Two of their four fighter group commanders were killed, “a blow that unnerved the increasingly hard-pressed Romanian Air Force.”
The largest mission of the entire Ploesti campaign took place on 15 July 1944. Nearly 700 bombers were tasked and almost half of them were directed against the Romana Americana refinery, dropping 1,500 tons of explosives and incendiaries. “The damage was significant,” Stout says, yet “within a short time, the enemy put repairs in place and the facility was increasing output day by day.” On 22 July, every available bomber was sent at the refinery that Americans had helped to build. Again the target was damaged, but not destroyed. Finally, on 17 August the Army Air Corps and the Royal Air Force unleashed a nonstop, three-day air raid that reduced the Romana Americana refinery to ashes. In total, 230 American bombers had been lost bombing Ploesti, nearly 14,000 tons of explosives dropped, and seven Medals of Honor awarded.
When the Red Army overran the city on 30 August, they were “astonished at the destruction,” Stout writes. Ploesti was operating at 20 percent capacity. Amazed that decadent American capitalists had actually destroyed their own property, the Soviets “were also angry they could not turn the wreckage to their own use.” Nazi Germany was retreating on every front, usually on foot, because they were out of gas.