Spotlight on Preservation Week: Emergency Preparedness in a New Era

Every year museums, libraries and archives around the country participate in Preservation Week to highlight preservation issues at both an institutional as well as a personal level. The New York City Municipal Archives is committed to the long-term preservation of all materials in its care. The Conservation Unit is responsible for the systematic planning and execution of preservation, rehousing, and conservation treatments of the holdings. Current projects include complex treatments on oversize architectural plans of the Brooklyn Bridge and Central Park, two of the most visually appealing collections in the Archives.

On this tenth anniversary of Preservation Week, the Municipal Archives is boosting its emergency preparedness plans. Having an up-to-date emergency plan has become increasingly vital in the era of climate change, and even more so now, amid a new type of emergency for most of us – a global pandemic.

With the Archives staff now teleworking, the normally very hands-on work of the Preservation Unit has shifted to what can be accomplished remotely. Conservators are diligently updating protocols, making plans for future projects, creating guides for future conservation interns, engaging in research and professional development, as well as supporting projects in other parts of the agency. Being removed from the Archives’ physical locations in Lower Manhattan and Brooklyn, however, has brought collections security and continuity of operations to the forefront.

Like most large collecting institutions, the Archives has taken steps to prepare for water incursions, fire, and other typical disaster scenarios, but social distancing has never been in the equation. COVID-19 has changed the landscape in dramatic ways.

As a result, the Archives has taken some immediate steps to ensure collections are safe, such as scheduling regular walkthroughs of storage areas, checking to make sure freezers containing collection materials continue to run properly, and monitoring environmental conditions. This is also an appropriate time to reevaluate the broader emergency plan and to think creatively about future staff training and other ways to enhance preparedness.

Municipal Archives staff assisted the Museum of Chinese in America with collections recovery following a fire in their storage space in January 2020. NYC Municipal Archives.

Current COVID-19 research indicates the virus lives on surfaces for a maximum of a few days. Thus, fears of returning to contaminated books and documents requiring disinfection are largely unfounded. Simply leaving items alone for three days would render them safe. The more pressing concern remains person-to-person transmission and high-touch surfaces that need regular disinfection.

Despite this bit of good news regarding collection material, the COVID-19 situation raises other questions.  How to maintain social distancing practices once staff return to work, while continuing to provide access to the collections? How does the typical use of personal protective equipment (PPE) change during this time of supply shortages? How to maintain preparedness, when budgets are reduced? Responses to these questions will evolve as more information becomes available.

A facilities engineer addresses a water leak in one of the Archives’ storage rooms. NYC Municipal Archives.

Our archivists and librarians are planning how to safely reopen and restore services when the time comes. Protocols will be put in place for handling collections after patron use, and stricter enforcement of hand washing or hand-sanitizing may be necessary.  While planning is still in the early stages, undoubtedly greater effort will be required to support communication and keep projects on track.

We are also reviewing collection processing protocols.  Archivists who rely on PPE when working with moldy or dusty collection materials, may not have immediate access to these items on return. The Department rightly donated its extra stock of disposable N95 masks to support healthcare workers during the pandemic.  The Municipal Archives may consider using non-disposable PPE where possible, but of course, this requires an upfront investment and additional maintenance. Respirator masks should also be fit-tested for each user to ensure that they provide adequate protection. In the long run, however, these moves may ultimately prove more cost effective as well as environmentally sustainable.

Boosting preparedness in times of economic uncertainty is no easy task; however, there are a number of steps we can take, such as adding pandemic and social distancing protocols to our existing plans and conducting staff training exercises once back at work among them. A number of state and local grants are available to help organizations develop emergency plans. New resources are also  available, such as the NEH’s recently announced CARES grants for cultural organizations.

A water-damaged ledger shows severe mold growth following a water leak. NYC Municipal Archives.

We must not to lose sight of the importance of future preparedness. Science and recent history have shown that disasters are an ever-increasing threat, particularly as the planet continues to warm. While budgets are strained in mitigating the effects of climate change and super viruses, protectors of cultural heritage must continue to think creatively in order to safeguard our history.

Conserving Central Park and Brooklyn Bridge Plans

The New York State Library recently awarded a grant to the Municipal Archives Conservation Unit to perform much needed treatments on large-scale drawings and plans for Central Park and the Brooklyn Bridge.

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Brooklyn Approach, East River Bridge, 1892. Wilhelm Hildenbrand, Brooklyn Bridge Collection, NYC Municipal Archives.

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Lindsey Hobbs pasting out a sheet of Japanese tissue with wheat paste for lining a Brooklyn Bridge drawing.

These two icons of New York are among the most important public works achievements in the city’s history. Beyond the technological and design innovations, the bridge and park have become symbols of the city itself. The more than 200 drawings that are the subject of the grant exhibit the remarkable level of detail and artistry that went into the planning and construction of each structure.

The project focuses on the largest items in each collection, some of which are 34 feet long! Conservation staff are undertaking a variety of activities to assess and stabilize these delicate materials.  These include mending and lining fragile drawings, stabilizing media, washing to remove harmful degradation products, reducing stains from mold and other sources on some of the most important drawings, as well as creating new housings for long-term storage.

The grant funding also supported the purchase of a Zeiss stereo microscope with a digital camera, and portable UV lights. This equipment allows conservation staff to analyze drawing media and supports, assess mold and other types of damage, and take high quality images of fine details, all of which will inform the treatment methods chosen. Additionally, the lab was able to purchase a large mono-stand for photographing oversized collections, both for documentation of the treatments performed as well as to provide another source of research access to these large, unwieldy objects.

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Clare Manias and Sara Bone surface cleaning a Brooklyn Bridge drawing.

The Brooklyn Bridge and Central Park plans comprise some of the most treasured collections at the Archives. Dating from 1850 to 1934, the Central Park plans provide complete documentation during the critical stage of the park’s design and construction from 1850 to 1880. The collection includes renderings of everything from landmark structures like the Boathouse, Belvedere Castle, and Sheepfold to a three-level circulation pattern for people, horses, and vehicles.  The oversized drawings included in the grant project detail the design of the Metropolitan Museum of Art and the Museum of Natural History, gates and entrances to the park, paths and walkways, drainage systems, and other elaborate details.

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Conservators Clare Manias and Sara Bone prepare to photograph a Brooklyn Bridge drawing.

The Brooklyn Bridge collection documents the original construction and subsequent alterations of the 1,596-foot steel suspension bridge connecting Manhattan to Brooklyn. At the time of its completion in 1883, the bridge was the longest in the world and was an important technological achievement. The total 8,706 drawings in the Bridge collection span from 1867 to 1938.  They were produced by architects and engineers who developed techniques for bridge construction that were unknown or considered unproven among their profession at that time. Many of the drawings in the collection are the work of the most celebrated American engineers and architects of the nineteenth century, such as John and Washington Roebling, George McNulty, and Wilhelm Hildebrand. The largest of these drawings is over 34 feet in length.

The drawings and plans in both the Central Park and Brooklyn Bridge collections have similar characteristics. They represent a variety of media (watercolor, graphite, inks, crayon, and photo-reproductive processes) and supports (tracing paper, watercolor paper, cloth-lined paper, and tracing cloth).  Unfortunately, improper storage and handling over the decades prior to acquisition by the Archives has led to physical damage to varying degrees in the form of acidic and deteriorated supports, flaking media, iron gall ink damage, and tears and fractures.

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Clare Manias and Sara Bone photographing a Brooklyn Bridge drawings in sections.

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Assistant Architect Wilhelm Hildenbrand included some delightful details in his 1877 plans for the Brooklyn Bridge. Conservation staff spotted these two almost microscopic figures enjoying themselves on the bridge. A gentleman in a top hat appears to be serenading a lady holding a parasol.

One of the greatest challenges of treating these materials is simply moving them back and forth from and within the lab. Conservators Sara Bone, Clare Manias, and I have developed a workflow for carefully shifting and transporting the drawings using light, but sturdy, foam board to support their weight. We have also refined methods for photographing, cleaning, and performing various treatments on a much larger scale than we are generally accustomed to. Planning each move in advance, and of course teamwork, are key to safely maneuvering these massive and very delicate drawings.

The ultimate goal, as with most of the work we do in Conservation, is to make the oversized drawings safer to handle, more accessible to researchers and well-preserved for the future. As the project moves forward in the coming months, we will continue to learn a great deal about the collections and further refine our treatment methods. Given the many thousands of oversized maps and drawings in the Archives’ collections, these skills will no doubt be put to use again once this project is completed. Although challenging, the work will ensure the viability of these iconic materials for many generations to come.

Iron Gall Ink

Archivists and conservators at the Municipal Archives face many challenges in their work to preserve and provide access to the City’s historical records. This week’s blog discusses the effects of the iron gall ink used to create some of the earliest documents in the Archives collection.

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Example of "burn through" in an untreated page with iron gall ink.

Iron gall ink was the ink of choice in the Western world for well over a millennium. Its indelibility and rich dark tone were desirable traits for artists, scribes, letter-writers, bookkeepers, i.e. virtually anyone documenting something on paper. While other types of inks were also available, such as carbon black and lamp-black ink, iron gall made up a significant proportion of the inks used up to the early 19th century, tapering off rapidly after that time. Iron gall ink, however, also has the unfortunate trait of damaging the paper it is written on. Over time and depending on certain conditions, the ink can fade to a light brown, create a haloing effect around letters, or “sink” through the paper. The ink in extreme cases will corrode the paper support, leaving areas of losses resembling burn marks in the paper. The effects can be seen in drawings by Leonardo Da Vinci, early drafts of the U.S. Constitution, and manuscripts of Victor Hugo, to name a few. The ink poses a formidable challenge for institutions with pre-19th-century manuscripts in their collections, including the Municipal Archives.

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Oak galls.

The effects of iron gall ink have long been known to conservators but are still not fully understood. The ink is composed of four main ingredients: tannins, which come from oak galls—a growth triggered by parasitic insects that attack oak trees; iron sulfate in the form of bluish-green salt crystals; a binder, usually gum arabic from the acacia tree, added to improve the flow of the ink; and lastly, water or wine. The ink achieves its rich bluish tone after the solution is exposed to air while writing.

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Iron sulfate

Research has shown that the two main ingredients in the ink, iron salts and tannic acid, each pose separate risks to paper, risks that are exacerbated by certain environmental conditions. The concentrations of the ingredients, the preparation method, the presence of other contaminates in the ink such as copper or zinc, the amount of ink that is absorbed into the paper, and even the type of writing instrument used, all influence and further complicate the degradation process. As a result documents that are produced at roughly the same time may exhibit a wide range of condition levels.

This variability is easily seen in the pages of manuscripts in which one page appears stable, while the adjacent page may show signs of severe degradation. In these cases it’s possible that the writer used a new batch of ink on the adjacent page or a new writing instrument, or even perhaps a new writer with a much heavier hand stepped in on the following page. It’s often impossible to say. These numerous factors, of course, complicate the role of the conservator, who must determine the best approach to treating and preserving collections.

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Book of 17th-century land conveyance records showing the variability in condition of different pages. NYC Municipal Archives Collections.

In some of the Archives’ original Dutch and English records, which document the founding of New York City by Dutch colonialists in the mid-17th century and the subsequent English takeover, the wide-ranging effects of iron gall ink are on full display. Some of the Dutch records were treated by Archives conservators in the late 1980s by a process called leaf casting. The treatment involves filling in losses on a damaged sheet via a water bath with new paper pulp. The water is slowly pumped out, allowing the pulp to fill in any missing gaps in the original document and create a more stable structure. The treatment also washes away water soluble iron II ions and acidic elements in the paper that contribute to its deterioration.

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Dutch records that were treated by leaf casting in the 1980s. NYC Municipal Archives Collections.

The documents that underwent this treatment more than 30 years ago are in markedly better condition today than those that have undergone no treatment. While leaf casting does not address the full range of issues that iron gall ink brings—a near impossible task for conservators racing against time and often less than ideal storage conditions—it has certainly proven to have been a worthwhile approach that likely prevented significant future losses.

The treatments available for collections with iron gall ink continue to evolve, as more research is conducted. And, additional options have been developed since these collections were treated years ago, such as a calcium phytate/calcium bicarbonate treatment. Municipal Archives conservators will continue to monitor the remedies for these important materials.