The Film Museum and its nitrate bunker

Martin van Leuven

Martin van Leuven standing before the nitrate bunker in Overveen.


On the De Koningshof estate in the woodlands of Overveen, there is a hidden concrete bunker where EYE has archived a large proportion of its flammable nitrate film stock. Martin van Leuven, Collection Manager for Film, reveals the secrets of the bunker.

“The Film Museum (now: EYE) was founded at the end of the 1940s and since then the Institute has tried to take care of increasing numbers of films. Early cinema was made on nitrate film stock and this was in storage across the country. When the museum was founded, there was a small storage facility in Castricum, but the collection continued to grow. It is not possible simply to hire a building in order to store nitrate film stock, because it is extremely flammable material and highly dangerous. A decision was made in the 1970s to build two nitrate bunkers: one in Scheveningen for the Government Information Service (Rijksvoorlichtingsdienst or RVD) and one for the Film Museum. Later, the Netherlands Institute for Sound and Vision took over the management of the RVD’s films. In the bunker in Overveen there are approximately 15,000 nitrate film canisters of the total number of 28,000 (16,000 films, 8,000,000 m) managed by EYE.”

“EYE has two other nitrate bunkers built just before the Second World War in order to protect the art from Amsterdam’s museums from theft and destruction. For example, Rembrandt’s Night Watch spent part of the war rolled up in the bunker in Castricum. The other bunker is in Heemskerk.”

“Unlike the bunkers in Heemskerk and Castricum, the bunker in Overveen was specially constructed to store flammable nitrate film stock. If a fire starts in one of the cells in the bunker, the pressure in the room increases and special fire vents open up to guide the flames outside, ensuring that the rest of the bunker remains undamaged. Outside, the fire is contained by concrete to prevent it spreading to the surrounding woodlands.”

“EYE’s main depository is in Vijfhuizen and contains approximately 150,000 canisters of film. These include films that can actually be used, including the latest movies. All of our depositories are almost full, so we need more storage space. We simply need more square metres of space, but also other methods of storage, for example roller shelving, paternosters or stacking robots. We are currently investigating what the best method is to use for the new building that will house the EYE collection on the other side of the IJ in Amsterdam. The entire collection will be stored there: all of the films, all of the digital media, all the posters, personal archives and photographs, but not the nitrate film stock, which will be kept in Overveen, Castricum and Heemskerk for safety reasons.”

Nitrate film stock: a fragile commodity

“It is often sheer luck that films managed to survive outside the bunker. Sometimes they were stored somewhere under a building, in a loft or in a shed behind the hay where they were amazingly well preserved because the conditions just happened to be favourable. Sometimes, we receive film canisters containing nothing but powder, which have to be destroyed because they are unusable. The whole process is highly unpredictable. Nitrate film stock is fragile. If it reaches a temperature higher than 40°C, it can spontaneously combust. The ideal conditions for storing it for long periods are at a temperature of 5 °C and an air humidity of only 35%. Special air conditioning in the bunker is used to create this unique climate.”

“The bunker contains both positives and negatives, but primarily positives. Generally speaking, nitrate films originate from the period 1896 to the middle of the 1950s, when the last remnants of nitrate film were used up and nitrate was banned. This means that some of the films are more than a century old! Nitrate film is always in a large format, 35 mm or 68 mm. The 68 mm films represent one of the most extraordinary film collections in the world. They were converted frame by frame to 35 mm film so that they could actually be used. Because of the danger of fire, it is no longer permitted to project nitrate anywhere in the Netherlands. This is why later films used acetate or polyester as a medium.”

Types of films

“There is an amazing variety of films and they come from every imaginable source. Most of the nitrate films originate from private collectors and we suspect that the majority have now been unearthed. Occasionally, we also discover the films or missing excerpts in our own archives, like the recently discovered Beyond the Rocks, a film starring Gloria Swanson. Sometimes we receive requests from other archives about a specific film or part of the film that is missing, so you know it must be important. When a piece of film like that is discovered, it is major news in the film world.”

“One extraordinary example is the film Lucky Star, which EYE pieced together and restored at the end of the 1980s, preserving it so it could again be viewed by the general public. At EYE, we also like to preserve and show examples of bad films, the type that cinema buffs might sneer at. Films like this often reached an enormous public or really capture the spirit of the age.”

“With nitrate films, it is the country of origin that is responsible for storage and conservation. There is a worldwide agreement (arranged by the FIAF) between all film archives, ensuring that films are returned to their country of origin.”

The people in the bunker

“No people actually work in the bunker. It is cold and dry and there is nowhere to work; just rooms with storage shelves where the film canisters are archived. There are regular weekly visits by depositary staff who come to bring films and collect them for the restorers.”

“The staff keep a record of all the materials that arrive and then make sure that these films also become available. The entire collection includes over 210,000 film canisters, divided into 30,000 nitrate and 180,000 canisters containing acetate film. Of these 180,000 canisters of acetate film, 20,000 are used each year across the globe, for example for showings at film festivals, universities and cinemas. In the near future, this distribution will be done digitally, but it currently remains a complex logistical process.”

Why go to all this trouble?

“In principle, we could simply make do with digital materials and acetate film (which can be stored for up to 600 years, given the right conditions). But EYE keeps the original nitrate film stocks because future technology may make it possible to preserve them more effectively. In any case, digital film is not considered to be archive material, but ‘access material’, suitable for publication. Ultimately, a tangible analogue film reel is the safest storage medium with the lowest loss of quality. There will probably come a time when we all decide no longer to preserve nitrate film stocks because of the enormous effort involved in keeping the bunkers running, but mainly because nitrate as a storage medium is so vulnerable to decay."

Images for the Future

“Thanks to the Images for the Future project, EYE has the resources it needs in order to make the collection accessible and to pass it on to the next generation. EYE is now employing as many as thirty additional people to work on this project. They are engaged in such activities as managing, storing, preserving, contextualising and digitising films, photographs and posters. This will ultimately allow us to make films available via digital channels, enabling them to be enjoyed not only by cinema buffs but also by people at home."

"We have a good working relationship with the other consortium partners and share the knowledge we acquire where possible. Despite this, each individual institution remains responsible for its own collection and also has its own specialism. EYE plans to include some material in iMMix, the Sound and Vision catalogue which allows you to arrange digital archiving and delivery, as well as the online film portal Filmotech. This means that at some point in the near future all the information will become available. It's an exciting prospect!”

Marcel Oosterwijk

About Martin van Leuven:

Martin van Leuven has worked at the Film Museum (now: EYE) since 1998 and is now the Collection Manager for Film. He originally worked for the technical drawings archive at the aircraft manufacturer Fokker. He swapped one archive for another in a quest for a more personal organisation. He says: “It all comes down to the same thing in the end. You allocate a number to something and then place it on the shelf so it can be found again later. You do not need to be a film fanatic in order to do this job.” He is currently hard at work on the new depositary to be built on the banks of the IJ.