In this blog, I will describe the research process for ACM 54 Normandy 1944, and the resources available to those wishing to research the Allied air strategy of the time. However, first a little background...

In the months before D-Day, one overriding question presented itself to the Allied planners: how could the German Army be slowed in its reinforcement of the invasion area? If the Germans won the ‘battle of the build-up,’ then the Allied armies could, conceivably, be driven back into the sea. With Soviet Russian forces advancing from the east, a failure by the Western armies would have far-reaching effects on the post-war map of Europe.

In early 1944, a civilian scientist at the British Air Ministry, Solly Zuckerman (an anatomist by training but, more latterly, an advisor to the Allied air forces in the Mediterranean campaign) proposed an answer. This was to use the Allies’ overwhelming superiority in the air to damage as much of the French railway system as possible to deny its use to German reinforcements and resupply in the early days and weeks after D-Day. Although much argument ensued, between March and July 1944, Allied air forces waged an intensive campaign against the French railway system.

Early research in 2023 revealed that the main story of the campaign boiled down to political and personal differences within the Allied high command and it was these which overlaid a dispute over the best pre-D-Day plan to adopt. In short, these were:

  1. Who was to be in overall command of the air forces? In the end, General Eisenhower, as Supreme Commander of Allied Forces, was given temporary control of all the Allied air forces.
  2. Which plan was to be adopted? The proposals discussed were:
  3. An attack on the French railway infrastructure –advocated by Solly Zuckerman.
  4. A continuation of the existing Allied heavy bomber campaign on German cities and industry –advocated by the RAF’s Arthur ‘Bomber’ Harris.
  5. An attack on Germany’s oil production industry by Allied heavy bombers – advocated by the USAAF’s Carl Spaatz.
  6. A small-scale ‘interdiction’ campaign by Allied fighter-bombers against bridges and other ‘chokepoints’ on the French rail network – advocated by a team of American scientists and economists.
  7. A combination of an attack on oil and an interdiction campaign – as a modification of the above options.
  8. Finally, would the campaign be allowed to continue in the face of heavy French civilian casualties?

Although the issues of command and the plan to be adopted were settled in March and April 1944, the issue of French casualties would weigh heavily on the consciences of many. Although Zuckerman’s Plan was adopted by Eisenhower, Spaatz’s oil campaign was allowed to go ahead from May, albeit in an initially limited way. Similarly, the fourth option – a tactical ‘bridge-busting’ campaign – would also begin a month before D-Day.

These differences of opinion affected the planning, the course of the Transportation campaign and subsequent assessments in the following decades. Those who had argued in the Transportation Plan’s favour maintained their stance, while those who opposed it, or suggested different plans of campaign, continued to criticise the Plan ever after. The battlelines drawn in 1944 remained until the 1980s, even affecting the later wars in Korea and Vietnam.

Therefore, the research rested on a number of lines of enquiry. What were the pros and cons of the Transportation Plan, and the alternatives put forward by Harris, Spaatz and the economists? Why was the Transportation Plan ultimately chosen? And most importantly, is it possible to sift through the mass of evidence and the web of claims and counter-claims to establish whether the campaign was effective or not?

The book’s research took me to four different archives: the RAF Air Historical Branch (AHB) at RAF Northolt, the RAF Museum archive at Hendon, the National Archives at Kew and the Zuckerman Archive at the University of East Anglia. The primary research was completed in one long trip, with three days spent in London and another at the UEA. Much travelling was necessary and, at one point, transport difficulties almost threatened to derail the entire exercise!

A marvellous resource, and one which proved to be the bedrock for further research, was the AHB Narrative (written not long after the campaign) and its vast number of associated appendices. These documents, consisting largely of meeting minutes, letters and planning papers may have looked dry but they gave an overview of Allied decision-making in the crucial months before D-Day.

The RAF Museum’s Lord Tedder Papers (Tedder was a senior RAF officer, Eisenhower’s Deputy Supreme Allied Commander and a good friend of Zuckerman). These documents demonstrate Tedder’s steadfast adherence to Zuckerman’s Plan – mainly because it offered a way of using the tremendous hitting power of the Allied heavy bombers. Tedder convinced Eisenhower of the Plan’s merits and he attended the interminable, and frequently unpleasant, meetings chaired by Winston Churchill to decide on whether the campaign should continue during April and May 1944.

The Tedder Papers also contained much correspondence with General Spaatz (the commander of the American Air Forces in Europe). Spaatz believed his air fleets could strike a decisive blow against Germany’s oil production, thereby fundamentally destroying their war economy. This could then open the door to a rapid German surrender, ending the war before Soviet forces entered Western Europe. It would also act as a catalyst for the long-cherished goal of gaining the USAAF’s independence from the US Army.

The National Archives is a rich seam of information, especially for RAF squadron and Group records, mainly the Operations Record Books (ORBs). These give a fascinating picture of Bomber Command’s nightly raids, with the detail reducing down to the stories of individual aircraft and crews. Sadly, some merely receive a poignant note such as, ‘Nothing further was heard of this aircraft after leaving base, and it is reported missing.’ At the more macro level, the Bomber Command Raid Reports, also held at The National Archives, provide overall summaries of each raid, with routes in and out of the target area, target-marking details and a summary of the enemy defences. An estimate of the success (or otherwise) of the raid itself is given, although these tend to be somewhat sanguine, especially in the light of later evidence...

Finally, after three days in London, I took a train from Liverpool Street to Norwich, from where I visited the University of East Anglia Archives & Special Collections. Zuckerman donated his voluminous collection of papers to the University, a large portion of which gave an incredibly detailed insight into the development of the Transportation Plan – and of course the vehement arguments which surrounded it. These include drafts and redrafts of the Plan itself, detailed endorsements and criticisms of the Plan from all quarters (military and civilian, British and American) and of course the uncensored correspondence between Zuckerman and various military service chiefs. Zuckerman himself was an exceptionally clever, if somewhat intellectually arrogant, scientist and his clashes with air force commanders, fellow scientists and even Winston Churchill were always forthright and often abrasive.

In addition, there was a vast amount of material which attempted to analyse the success of the bombing campaign on the French railways. However, as pointed out in the book, the Plan’s results were clouded by the tactical campaign, which began a month before D-Day. Rail movements, and supply and reinforcement problems, were affected by both Zuckerman’s original strategic bombing campaign and the bridge-busting campaign. The proponents of each were eager to take the credit for the overall campaign’s undoubted success. However, the sifting of evidence from the rubble of French towns, railway marshalling yards and bridges served only to produce a mass of conflicting claims. Perhaps of more importance was the testimony provided by the French and German railway officials in post-war interrogations, from which it appears that the more effective campaign was the (predominantly American-backed) tactical campaign.

As a coda to this, I should point out that prospective researchers should treat the problems of travel more cautiously than I did. My original plan, to return from Norwich to Preston in the same evening almost went awry immediately, when in the chaos of rush-hour, no taxis were available at the UEA. Eventually, after much difficulty, a taxi was booked, only for the driver and myself to spend much time searching for one another in the rain and gathering gloom of a November afternoon. We reached Norwich Station in time however, from where I took a train to Liverpool Street, a tube train to Euston, and a West Coast mainline train to Preston, arriving just after midnight. After a forty-minute taxi ride back home from Preston, this exhausted researcher fell into bed at around 1.00am, after a long but fruitful day!

Finally, many thanks are due to Andrew Dennis (RAF Museum), Stuart Hadaway and Lee Barton (RAF AHB) and the staff at the National Archives, Kew and Bridget Gillies at the University of East Anglia.

You can read more in Normandy 1944: The 'Transportation Plan' to cut D-Day communications