Library stacks tend to be functional, consistent in appearance, and, while a source of delight to bibliophiles, pretty ordinary.

However, the stacks at the National Library of Medicine have tales to tell.

Literally and figuratively, the stacks at NLM are the foundation of the world’s largest medical library, occupying three football field-sized floors beneath the main library building.

The contents of about 30 million books, journals, manuscripts, audiovisuals, and other items are used by patrons in the Library’s two reading rooms and by interlibrary loan (ILL) patrons all over the world. But the stacks are mysterious. They’re closed to the public.

We wanted to give you a behind-the-scenes glimpse of what really happens in NLM’s stacks.

Why are they underground?

The NLM stacks are on three underground floors, each about the size of a football field. If you placed the stacks end to end, they’d cover about 65 miles, or the distance from NLM in Bethesda to Hagerstown, Maryland.

The reason they are underground has a lot to do with geopolitics and the Cold War.

The architecture firm O’Connor and Wilham of New York City were authorized to begin work on the building in early May 1957, during the height of the Cold War. Their design that won the job took seriously the threat of bombs or some other weapon from the Soviet Union being directed at Washington, DC. Bethesda is right on the DC line.

With the depth and breadth of NLM’s holdings, including a manuscript from 1094 and first editions of Darwin, Harvey, Nightingale, and other luminaries, not to mention it being the medical library of record for the world, keeping the collection safe and secure was a top priority.

It still is, although the major threats today are flooding, fires, insects, and mold.

Collection access in the stacks

If you think the stacks might be a quiet place, guess again.

“Things are always hopping on all floors,” said Access Unit Head Mary Wassum with a laugh. “We’re scanning, we’re pulling volumes, we’re doing quality control. You’ll never get lost in the stacks because people are always walking around. In fact, there’s good camaraderie on all three levels.”

Wassum works in an office on the uppermost of the three underground levels, B-1.

“The NLM Collection Access Section is kind of the gateway to the collection,” she explained. “We help remote users gain access to items via interlibrary loans, and we take care of the main reading room operations, assisting patrons who are on site. My people interact with them—pulling books, answering questions, issuing library cards, and more.”

In fiscal year 2017, NLM filled 121,000 interlibrary loan requests for patrons from around the world.

Employees need to be fast on their feet. Reading room patrons, who can request up to 50 items per day, typically see their requests turned around within an hour. ILL patrons receive their requests within four hours. NLM typically handles 500-600 of those each business day.

When on-site or ILL patrons request items, NLM achieves an 82 percent fill rate, noted Mary Wassum. What of the remaining 18 percent? A book or journal might be in use somewhere else, or maybe a patron wants an item that’s not within the Library’s scope or isn’t in its catalog.

When a hospital library has a clinical emergency request, NLM has a dedicated queue to receive those requests and fulfill them within two hours. NLM typically sees three to five of those a day.

“It’s all about teamwork,” said Wassum. “We all believe in the mission, and we have great interpersonal relationships and a lot of mutual respect.”

The mission is simple: To get important health and medical information to those who need it, as quickly as possible.

“The collection is always evolving, just as it always has,” said Wassum. “Today, the paper-based and e-based parts of the contemporary journal collection are almost 50-50. Some are nostalgic for the paper versions, and there’s a place for that. But we’re forward thinking. The electronic versions are much easy to handle and share. People can get the information they need in seconds.”

Collection development in the stacks

“Collection development is part of the Technical Services Division. We collect and acquire biomedical materials comprehensively, then organize them here,” said Margaret McGhee, formerly of the Division. “Our bread and butter on site is binding, shelving, and maintaining the physical collection. That also means organizing the space for the collection, planning for growth, making sure it’s safe from hazards like pests, water, and theft. We think about the past, present, and future.”

“As the NLM collection becomes increasingly electronic, fewer bound items mean more space for us,” explained McGhee. “It also shifts our focus—how can we make items available via the web and other platforms? We need to digitize items in the collection that might be at risk, because the paper is flaking or something. We work with the History of Medicine Division to digitize items in the audiovisual collection that are in very old formats or are starting to disintegrate, or both. This work is less about access and more about preservation.”

McGhee likes to think of NLM having several pillars. “Certainly, the physical collection is one of those. The NCBI databases, heavily used by people all over the world, I would say is another. And the Library’s new focus on data science is probably going to reveal other pillars we haven’t even thought about yet,” she said.

Preservation in the stacks

Walter Cybulski, who manages scanning projects at NLM, started his career as the preservation coordinator of the New York State Newspaper Project (part of the United States Newspaper Program), an effort to microfilm newspapers from all 50 states. In 1996 he arrived at NLM, where he familiarized himself with charts and transparencies detailing the contents of the three levels of stacks, plus collection priorities, in the event of a fire, flood, or other disaster.

Needless to say, it is a formidable challenge.

“Preservation is an umbrella term for the effort to extend the useful life of collections,” Cybulski said. And there are several elements that go in to preservation, among them:

• an understanding of the building: structure, climate, and storage requirements for different media, like print and non-print holdings (“You learn a building the way you learn a person, idiosyncrasies and all,” said Cybulski.)
• disaster preparedness
• the need for ongoing vigilance, which includes monitoring storage area environments.

And this former literature and poetry major knows how to employ a useful metaphor.

“There are stacks of understanding,” Cybulski explained. “I like to think of them as different layers of awareness.” For example:

• You need to protect the collection from the environment.
• You need to have the correct environmental conditions to begin with. “The fact that the Library was built as a bomb shelter, with a thick concrete wall all around the stacks, actually did us a favor,” said Cybulski.
• You have to be aware of the location of air handlers and understand how well they are performing.
• Finally, you need to know what NLM’s compact storage system is made of and how many fully loaded shelving units the floors can safely support.

So, what are some of the tools of the trade for preservation at NLM?

• Wet vacuums
• Plastic sheeting to cover books when the sprinkler system comes on
• Absorbent fabric to put on wet floors
• Freezers to stabilize wet books and journals so they can be freeze-dried with minimal damage

Surprisingly, it’s not always the oldest items that require the most attention.

“Thirty years ago, the best way to preserve paper was on microfilm. The mid-19^thto early 20^thcenturies are considered to be the ‘brittle paper era,’ when unbleached wood pulp was used to manufacture paper. Not a good idea,” explained Cybulski. “Today, we’re prioritizing which items we should be scanning for preservation.”

NLM shares its preservation knowledge with the world. Cybulski teamed with NLM conservationist Holly Herro to edit a series of videos from the American Institute for Conservation of Historic & Artistic Works into brief, “quick reference” segments.

Going forward

“There have been changes in technology, changes in the selection process for the collection—there will always be change—but there is also an ongoing core activity, caring for the collections,” said Cybulski. “Whether it’s on paper or digital, we want to keep the collection stable and usable.”

Thankfully, for the professionals in the stacks at NLM, regardless of what they’re doing, there’s a lot of joy in their work.

More information

Walter H. Kilham, Jr. “Housing the Library Part II: The New Building.” Bulletin of the Medical Library Association. 1961; 49 (3):403-410.

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Credit for the title of this article should go to Dee Clarkin, former deputy chief of NLM Public Services Division, who gave a presentation and tour with the same name to NLM staff members years ago.

By Melanie Modlin, former NLM in Focus staff writer