The Secret History of RDX

The Super-Explosive that Helped Win World War II

Colin F. Baxter

• Publisher: The University Press of Kentucky
• Year: 2020
• Print ISBN: 9780813175287
• eBook ISBN: 9780813175317
• Topic: History
• Subtopic: Military & Maritime History
• Index: History

The noted historian offers "a compelling sociohistorical account of an often overlooked yet critical" WWII explosive twice as powerful as TNT ( Choice).

During the early years of World War II, American ships crossing the Atlantic were virtually defenseless against German U-boats. Bombs and torpedoes fitted with TNT barely dented the hulls of Axis naval vessels. Then, seemingly overnight, a top-secret manufacturing plant appeared near Kingsport, Tennessee, producing a sugar-white substance called Research Department Explosive, code name RDX.

Twice as deadly as TNT and overshadowed only by the atomic bomb, RDX proved to be pivotal in the Battle of the Atlantic and directly contributed to the Allied victory in WWII. In The Secret History of RDX, Colin F. Baxter documents the journey of the super-explosive from conceptualization at Woolwich Arsenal in England to mass production at Holston Ordnance Works in east Tennessee. Baxter examines the debates between RDX advocates and their opponents and explores the use of the explosive in the bomber war over Germany, in the naval war in the Atlantic, and as a key element in the trigger device of the atomic bomb.

Drawing on archival records and interviews with individuals who worked at the Kingsport "powder plant," Baxter illuminates both the explosive's military significance and its impact on the lives of ordinary Americans involved in the war industry. Much more than a technical account, this study assesses the social and economic impact of the military-industrial complex on small communities on the home front.

1

Lord Beaverbrook, RDX, and the Ministry of Supply

By June 1940, the Battle of France was lost and the Battle of Britain was about to begin. At the battle’s height, on 3 September 1940, Churchill declared, “The Fighters are our salvation, but the Bombers alone provide the means of victory.”¹ Writing to his close friend Lord Beaverbrook, the minister for aircraft production, Churchill said, “We have nothing to stop him [Hitler]. But there is one thing that will bring him down and that is an absolutely devastating exterminating attack by very heavy bombers from this country upon the Nazi homeland. We must be able to overwhelm them by this means, without which I do not see a way through.”²

At the end of the 1940, however, Churchill noted in an “Action This Day” memorandum, “I am deeply concerned at the stagnant condition of our bomber force.… I consider the rapid expansion of the bomber force one of the greatest military objectives now before us … the situation is most distressing and black.”³ Bomber crews had displayed unquestioned determination and bravery in carrying out their missions, but the RAF Bomber Command’s aircraft were neither numerous nor accurate enough to inflict heavy damage on the enemy.⁴ Bombs filled with the explosive Amatol were unable to fulfill the very purpose of the bomber, which was to carry bombs that would cause maximum damage to the enemy. Furthermore, the ratio of explosive to the weight of the bomb itself was too low, between 27 and 30 percent, compared to the 50 percent in German bombs.⁵

Beaverbrook informed Air Marshal Sir Richard Peirse, the chief of Bomber Command, that he was “alarmed that we have no real brains working on the question of improved explosives.”⁶ Beaverbrook told Peirse that he had been to Woolwich Arsenal and gained the impression that “except for the costumes, we had stepped back into the Crimean [War] period.”⁷ Beaverbrook stated that he had written to Sir Henry Tizard, the scientific adviser to the Air Ministry, asking whether they were using any outside sources, such as I.C.I. [Imperial Chemical Industries]. In the absence of Tizard, Air Commodore Patrick Huskinson had replied they were not; however, Huskinson informed him that there was a new and much better explosive than TNT, but it was only produced in “penny packet numbers” by the Ministry of Supply, and that unless pressure was applied on the Ministry of Supply by higher authorities increased quantities of the new explosive were unlikely. “It goes by the name of RDX.”⁸ Beaverbrook suggested in his letter to Peirse that they submit a paper to the Defense Committee demanding the “most urgent action” for an increased supply of RDX.⁹

Beaverbrook’s proposal stated that experiments at the Woolwich Arsenal over the past fifteen years had shown that RDX gave 30 percent more power than any of the explosives now used in their bombs, and its use by the RAF “will immensely increase our offensive bombing power.”¹⁰ He stated that the only RDX plant “in existence today” was at Bridgewater, which was expected to make sixty tons per week in September 1941, an amount that would “meet only a small proportion of the needs of the Royal Air Force.… Urgent consideration should therefore be given to the provision of further plants and facilities so that a minimum output of 600 tons a week can swiftly be reached.”¹¹

Beaverbrook’s proposal was soon in the hands of the director-general of explosives at the Ministry of Supply, Lord Weir, who responded that “the first task” of the Ministry of Supply had been to make provision for sufficient production of the standard explosives TNT and ammonium nitrate.¹² Somewhat defensively, Lord Weir wrote, “The problem of providing the Services with a super high explosive has never been lost sight of … [after the defeat of France] we hoped to interest United States authorities in the adoption of either RDX or some similar type of super high explosive through Sir Henry Tizard’s visit but the response was not enthusiastic.”¹³ Instead of RDX, Weir suggested as an alternative filling RAF bombs with the explosive Pentolite, which could be manufactured more quickly and cost less: “For example, to make 1 ton of TNT or Pentolite, 1¼ tons of concentrated Nitric Acid is required, but for RDX 10 gross tons is needed.”¹⁴ Pentolite, said Weir, was around 20 percent more powerful than TNT as opposed to 30 percent for the RDX. As for Beaverbrook’s proposal to build a plant able to produce 600 tons of RDX a week, Weir argued that it would require the construction of nine units the size of the Bridgewater plant at a cost of £9 million and take between “two and three years” to construct.¹⁵ He recommended that in view of the magnitude of the proposed expansion, and the “congested state in this country of construction and equipment programs,” that “on whatever scale further RDX production may be decided upon it should be carried out in the U.S.A.”¹⁶ They were negotiating through the British Purchasing Commission in Washington for the possible supply of RDX from the United States.¹⁷

In a letter to Sir Andrew Duncan, the Minister of Supply, Beaverbrook declared that he could not accept Lord Weir’s position on RDX or accept Pentolite as an inferior substitute for RDX. As long ago as 1934, stated Beaverbrook, the Research Department at Woolwich reached the conclusion that RDX was superior to Pentolite. In Beaverbrook’s opinion, there had been “a serious failure in the past” to push forward construction of RDX facilities.¹⁸ However, wrote Beaverbrook, “the past concerns neither you nor me, what is evident is the need for immediate action now to increase production of this explosive, for large quantities of which the Air Staff are already pressing.”¹⁹

On 12 March 1941, Dr. J. W. Armit, deputy director-general of explosives at the Ministry of Supply, presided over a ministry meeting to discuss RDX production. After considering Bomber Command’s request for as much RDX as possible to fill all types of bombs and the Navy’s antisubmarine requests for Torpex, Dr. Armit informed Lord Weir, “I think from all points of view it would be best to try all means of getting the United States Government to erect these [RDX] plants as part of its own rearmament program.”²⁰ Armit added, “I am seeing, this morning, Dr. Conant, who I understand is one of President Roosevelt’s chief scientific advisers, in this connection.”²¹

Beaverbrook’s efforts on behalf of Bomber Command were appreciated by Air Chief Marshal Sir Charles Portal, chief of the Air Staff: “I was very glad to hear … that you were fighting for a proper production of the new explosive known as RDX. I view the introduction of RDX on an adequate scale as a matter of very great importance since it will greatly enhance the effect of every bomb so filled which we can deliver into Germany. I am told that the destruction caused by a 500 pound general purpose bomb is increased by 50% by the use of R.D.X. There is no need to stress the value any further.”²² Although Portal considered the production of RDX “of very great importance,” the Ministry of Supply made it quite clear that any new plants beyond that at Bridgewater were impossible.

2

The Vexed Question of RDX Supply

There now began a vigorous British campaign to convince American authorities to manufacture RDX on a large scale “as a matter of great urgency.”¹ Their greatest challenge would be to convince the U.S. Army Ordnance Department of the importance of RDX, since that department was responsible for supplying munitions to the Army, as well as the Army Air Forces and Navy.

The Air Ministry believed that the U.S. military services preferred to deal with one body on air matters, and that would be the RAF Harris Mission. Lord Beaverbrook, however, argued that Britain’s best friends in America were not the Army or Navy, but the president and his civilian advisers, who could override “where necessary the inevitably professional view of the Service chiefs.” Before the supply question was finally resolved in 1943, both approaches would be necessary to surmount opposition from the Ordnance Department to RDX.

In June 1941, Air Vice-Marshal Sir Arthur T. Harris arrived in Washington to head the RAF mission in America. After discussing RDX requirements with General H. H. “Hap” Arnold, chief of the U.S. Army Air Forces, Harris cabled Air Chief Marshal Portal that Arnold was “definitely interested” in the superexplosive, but the Army Ordnance Department regarded RDX as unsafe.² Harris also cabled Sir Wilfred Freeman, vice-chief of the Air Staff, “In order to get and keep [the] right people here interested and sell them the idea of RDX on [the] grand scale must have necessary sales patter and pictures.”³

Harris was quickly provided with what little firsthand operational material was available, since their very limited supply of RDX restricted its use to only a handful of 4,000-pound “Blockbuster” bombs.⁴ Most of this information was derived from the bombing of the German port of Emden on the North Sea. Freeman added that RDX, in the form of Torpex, had also been used in an airborne antisubmarine depth charge, and “RDX proved itself excellent in both these cases, and considered ideal for filling any type of bomb.”⁵

At the end of April 1941, Air Commodore Huskinson, director of armament production, informed Air Marshal Peirse, chief of Bomber Command:

You will be pleased to hear that we are delivering to you this coming week 12-4,000 lb. bombs filled with RDX as these bombs have been asked for by the Air Staff for a special purpose. The bombs contain the very latest type of explosive which gives Approximately 30 percent increase over the present filling.

I am writing to you so as to make sure that no accidents occur and that these bombs are not used on ordinary targets.

You will be glad to hear that I have more or less recovered from a very nasty shake-up, but I am still blind in both eyes. However, I hope to regain my eyesight shortly. I hope these 12 super bombs will be put in the right place as I feel very angry towards the “Hun.”⁶

The first of the “super bombs” dropped in World War II made their operational debut on the night of 31 March 1941, when two of them were dropped on Emden.⁷ Air Marshal Harris was informed that “Bomber crew reports indicate tremendous effects of explosion often felt as high as 14,000 feet and causing debris, flame and smoke over wide areas.”⁸ Aerial photographs confirmed the reports of the aircrews and indicated “tremendous devastation and blast effect at 200 yards from point of impact.”⁹ Reliable intelligence sources described “the demoralizing effect on Germans who are extremely apprehensive and dread more extensive use [of] these bombs.”¹⁰

Huskinson, who shared the reports with the American ambassador, John G. Winant, remarked that the bomb had “supremely justified itself.”¹¹ Reconnaissance photographs confirmed crew reports that the first bomb obliterated every building in an area of approximately 100 by 80 yards, and the German High Command described the blast damage as “severe.”¹²

The American public was made aware of the new 4,000-pound bomb by Time magazine, which under the heading “Beautiful New Bomb” carried the story that Minister of Aircraft Production Lord Beaverbrook had praised the “boys in the back room [scientists and technicians]” who had helped design “the big new beautiful bombs.”¹³ One witness of a big bomb dropped on Hamburg described the effect as “like a volcano in eruption.”¹⁴ Later in 1941, Beaverbrook would be reminded of his public praise of the “boys in the back room” when he appeared to accept U.S. Army Ordnance Department skepticism about RDX.

General Arnold was so impressed by the destruction inflicted by the 4,000-pound “Blockbuster” bombs that he requested Army Ordnance to produce a bomb of similar design.¹⁵ Full particulars of the RAF bomb were sent to the British Air Commission in Washington.¹⁶ However, in the Army Ordnance Department, Generals Gladeon M. Barnes and Richard H. Somers doubted whether the 4,000-pounder would be as effective as two 2,000-pound bombs.¹⁷ Assistant Secretary of War for Air Robert A. Lovett intervened and ordered the continued development of the 4,000-pound bomb.¹⁸

The British submitted their first request for 6,500 tons of RDX on 2 May 1941 and asked that it be delivered at a rate of 125 tons per month, with the deliveries “to start as soon as possible.”¹⁹ Two weeks later, representatives of the British Supply Mission asked the Ammunition Branch to discuss their RDX requisition. Why did the British submit the requisition to the Ammunition Branch, which was relatively low down on the Ordnance Department’s organizational chart, and not to Ordnance’s Technical Staff? Dr. Robert O. Bengis, chief chemist in the Ammunition Branch, later recounted, “It was the feeling of the British that they had completed the research and development program” on RDX, and by making their designs available to the Ammunition Branch, it would be possible to initiate immediate RDX production in the United States.²⁰ Moreover, the British may have felt that Ordnance’s Ammunition Branch would be more receptive to their requisition than the Technical Staff headed by General Gladeon M. Barnes, described in Ordnance’s official history as “a dominant figure on research and development matters” in the Department from 1938 to 1946. A skilled engineer, and sure of his own judgements, Barnes’s opponents regarded his “refusal to consider contrary opinions a very great weakness.”²¹ Barnes believed that Ordnance was fully capable of carrying out its own research program without the intervention of any other agency.²²

Several conferences involving British, U.S. Navy, and NDRC representatives followed in the Old Munitions Building in Washington. Major G. C. Tibbitts of the Ammunition Branch noted that “the British have strongly emphasized their desire for utmost secrecy on the whole subject of RDX and have also stressed the extreme urgency of their requirement for RDX.”²³ Commander Holsinger stated that the Navy “definitely” required 120 tons of RDX per week.²⁴ Although the Army made no official request for RDX, Colonel Henry S. Aurand said the Army should not be left out of the RDX program.²⁵

Once the Navy’s request for RDX was known, the Ammunition Branch recommended that a contract be negotiated “immediately” to cover the development and pilot plant work necessary for the design and operation of the first RDX facility in the United States.²⁶ The main plant would have the capac...

Table of contents

• Cover
• Title Page
• Copyright
• Dedication
• Contents
• List of Abbreviations
• Introduction
• 1. Lord Beaverbrook, RDX, and the Ministry of Supply
• 2. The Vexed Question of RDX Supply
• 3. Torpex and the Air War
• 4. RDX and the Army Ordnance Department
• 5. RDX and the Army Air Forces
• 6. The Battle for RDX Production
• 7. Canada and RDX
• 8. The Wexler Bend Pilot Plant
• 9. The Great Holston Ordnance Works
• 10. Torpex and the Battle of the Atlantic
• 11. 1945 and the Atomic Bomb
• 12. The Aftermath
• Epilogue
• Acknowledgments
• Notes
• Bibliography
• Index