Sources of information about Project Habbakuk

The Wikipedia article on Pykrete cites these properties. While its crushing strength is inferior to concrete, it compares favourably weight-for-weight. It has greater tensile strength, and is far less dense.

Interestingly, it is slightly denser than ice (0.98g/ml, compared with 0.91g/ml for pure ice), and a simple chunk of pykrete would float far lower in cold water than a similar-sized chunk of ice. I should be able to confirm this with my own samples, using the Archimedes principle.

Polymer scientist Herman Mark was the first to propose using wood pulp to strengthen ice, and describes the proposal in his 1993 autobiography, From Small Organic Molecules to Large.

Max Perutz published this schematic diagram of the bergship and described further properties of pykrete in his 1948 paper, A Description of The Iceberg Aircraft Carrier, in The Journal of Glaciology, volume I. In my next post, I shall discuss data from this paper.

Perutz discusses his wartime experience and his work on the project in his essay Enemy Alien published in I Wish I'd Made You Angry Earlier and in Is Science Necessary? His biographer, Georgina Ferry, expands further in Max Perutz and the Secret of Life (2007).

J D Bernal's part in the project is described in two biographies: J.D. Bernal: A Life in Science and Politics by Brenda Swann and Francis Aprahamian, and Andrew Brown's J. D. Bernal: The Sage of Science.

While David Lampe's 1959 biography, Pyke, the Unknown Genius, gives a particularly fanciful account, it does provide this fabulous cutaway diagram of the proposed HMS Habbakuk.



There are apparent discrepancies between the various accounts. I hope to make a trip to Kew to visit the National Archives soon. They have various documents relating to the project, including Adm. Noble's reports on Habakkuk/Tentacle and Proposals and inventions of Mr Geoffrey Pyke; gravity propelled ball bomb, pykrete and power driven rivers which may help to clarify the history. Or else muddy the waters still further with a mush of wood pulp.

Beyond the LCC maps – further resources for investigating London’s war

Great though the LCC maps are, they only give us a snapshot of damaged property in 1945. They tell us nothing about when the bombs fell, how many there were, or what kind of bombs. They also tell us nothing about casualty numbers.

But these data were carefully collated throughout the war, and documents in the London Metropolitan Archives and National Archives help to extend our understanding of the period.

The London Metropolitan Archives hold the incident logs kept by local authorities, which detail the number and type of bombs received, and damage and casualties incurred. They were also plotted on bomb census maps, held by the National Archives:


Bomb Census Map for South East London, October 1940.

These data were used to estimate density of attacks over the entire London Civil Defence Region - a larger area than the LCC maps cover, roughly corresponding to the Metropolitan Police Area.

This map from the National Archives shows density of bombing in the London region from outbreak of hostilities to October 1941. This shows how heavily the whole of Central London, both north and south of the river was bombarded, alongside dock areas and Chelsea


The National Archives also hold tables of incidents. This table shows incidents by area for 2 weeks during the height of the V1 attacks in summer 1944.


The London Civil Defence Region also produced maps of V-weapon strikes. These were widely scattered, but concentrated south of the river. What this map does not show is the number of bombs shot down or falling short of the target in Kent.

Map from the National Archives showing V1 attacks up to 7th August 1944.


All these documents are freely accessible to the public at London’s archive centres. Together with the LCC maps, they form a formidable resource for anyone interested in London’s wartime history, helping to provide the chronological framework and document the human cost of the bombing of London.