Sprinkler Test Simulation for HDS Shelving Array
Participants and contributors
- University of Illinois, Urbana-Champaign (UIUC) Library, Preservation and Conservation Units: Heather Tennison, Laura Larkin, Jennifer Hain Teper, Tom Teper
- Senior Engineering Team, Department of Industrial and Enterprise Systems Engineering (IESE), UIUC: Chris Manna, Tim Kennedy, Ian Bradley
- Illinois Fire Services Institute (IFSI): Richard Jaehne, Brian Brauer and Gavin Horn
- Academy of Fire Sprinkler Technology (AFST), Parkland College: Cecil Bilbo, Director
On Monday, April 27, 2009, the UIUC Preservation Unit in collaboration with a Senior Engineering Team from the UIUC, IESE and in coordination with IFSI and AFST conducted a live sprinkler test on a 5 foot section of high density storage shelving. The purpose of this test was threefold:
- Observe and record the effects of a sprinkler deployment on the top 5 feet of shelving in a realistic, “live,” scenario including
• the level of water penetration within the top 5 feet of a HDS array
• the total weight gain of full HDS trays (both special and general collections) and record storage boxes after a sprinkler deployment
• the total weight gain of the 5 foot array after a sprinkler deployment
• the dimensional growth and weight gain of individual items shelved within the trays (both housed and un-housed)
- Assess the structural soundness of special and general collection trays and record storage boxes in a real time scenario
- Assess tray extraction techniques and determine the feasibility of alternate extraction methods (if needed)
Development of testing protocol
The two storage modules in the Oak Street Library Facility are outfitted with 94 K-22 Early Suppression Fast Response (ESFR) Reliable sprinklers, each of which activates independently when temperatures exceed 200ºF. The K-22 sprinkler head is designed to discharge 142 gallons of water per minute at 40 psi to prevent the fire plume early in its development, stopping the fire from spreading and reducing roof level temperatures quickly to prevent structural damage to the shelves and the facility. This sprinkler head is designed to extinguish fire – not suppress fire spread.
Installation specifications for the K-22 ESFR are based upon an open rack/pallet system (where discharged water could actively penetrate within the shelving array, quickly extinguishing an active fire event). To date, there has been no published testing of these types of sprinklers within a closed rack environment (like that found in the HDS facility). Investigations looking at fire movement within a closed shelving system and the effectiveness of sprinklers (including the use of in-rack sprinkler systems) in fire management within these types of systems are currently being conducted at other partner institutions. It should be noted, however, that the UIUC HDS does not have in-rack sprinklers, so our system will react differently from that being tested.
In light of the differences between closed and open rack shelving, the engineering team was interested in gauging the effectiveness of the K-22 ESFR system as currently installed and in developing a greater understanding of the flow and movement of the water upon the shelving towers. Using a NIST Fire Dynamic Simulator (a computational fluid dynamics (CFD) model of fire-driven fluid flow) the team was able to model the water flow and spray pattern of the facility’s sprinkler heads by specifying parameters such as pressure, velocity, flow, and sprinkler head size. The simulation showed that the top 5-7 feet of the shelves receive the majority of the water (see figure 1); spots below this are reached indirectly through cascading water.
The team observed that levels of pooling within the upper range of the shelves varied depending on the configuration of sprinkler head to shelf array (the sprinkler heads are positioned in a 9’ grid pattern to allow for overlap of the water cones in the event of a deployment – there is no intellectual correlation between the location of the sprinkler heads and the location of the shelving below, as per the open rack specifications) and determined which configuration would result in a “worst case scenario” (i.e. the sprinkler head to shelving configuration that would result in the maximum amount of direct water penetration and damage) to be replicated within the live sprinkler test.
Materials and methods
Applying the information learned via the computer modeling, it was determined the test configuration would be as follows (see Figure 2):
- One 5’ section of SpaceSaver Xtend Stationary High-Bay Shelving was fitted with 6 shelves. Shelf heights were in conformance with the spacing used in the Oak Street Facility (First space/shelf – 12”; second shelf – 9”, third shelf – 8”; fourth shelf – 8”; and the fifth shelf – 10”)
- 27 general and special collections book trays (25 general, 2 special); 1 archival record storage box; 4 general collection quarto trays; and 2 bundles of boarded/wrapped newspapers were prepared for placement on the shelves (see Appendix B table 1)
• Each full tray was photographed and weighed prior to the test
• The number and % of hard cover books vs. soft cover books was tabulated for each tray
- Notations were added documenting the shelf (1 being the topmost shelf, 5 being the bottommost) and the tray’s location on the shelf during testing (B = back row; F = front row; 1 = leftmost facing position, 6 = rightmost facing position upon the shelf)
- Select books were tagged and their statistics documented (see Appendix B table 2)
• Each book was measured, weighed, and photographed prior to the test
• The book’s placement within the tray was noted
• If any additional housing was to be tested, the housing type and total weight of the book + housing was also recorded
- The shelving was mounted onto a steel pressure mat to allow calculations to be made on total set-up weight before and after the test
A second shelf was placed 4” from the backside of the Xtend shelving array to replicate the HDS ‘chimney’ (see figure 3)
- A plywood board was placed 5’ in front of the Xtend shelving array to mimic the facing shelving unit and any back-splash that would be generated by such a unit (figure 4).
- One K-22 ESFR Reliable sprinkler head was connected to a 6” diameter pipe fitted with a 1” orifice and placed 3’ above the shelving system and 18” in front of the shelf with the assistance of a forklift (see figure 5)
- Video cameras were placed in front of the testing site (right facing) and on the left facing side of the shelf to document the test
- Still photographs were taken before, during, and after the test to document the test as thoroughly as possible
- The sprinkler was deployed and allowed to run for 30 minutes (the amount of time it would take fire personnel to arrive on the scene, make their initial assessments, and turn the water off)
- Post sprinkler deployment, ease of tray extraction was tested and documented
- Trays and individually tagged books within the trays were weighed, measured (if applicable), and photodocumented
The observable flow of water upon the array was, in general, as anticipated by the modeling software. The trays lining the front of the upper shelves were directly hit by the sprinkler spray in a severe downward motion (causing both pooling of the water within the upper trays and shelves as well as a shearing of the front of the trays and books) and a cascade could be seen forming lower upon the array. What the software and internal team discussions did not foresee was the ‘waterfall’ effect that was observed when the large amounts of high pressure water hit the top ‘roof’ of the shelving tower (see figures 6 & 7). This ‘launching’ effect caused a continuous stream of water to fall into what would be the upper shelves of the back facing array.
The two special collections trays failed at 13 minutes into the test (the tray located in the far right facing position on the second shelf) and 16 minutes into the test (left facing, top shelf). Failure of these trays appears to have been caused by an inherent weakness in the tray construction material (acid and lignin free fluted cardboard). This can be assumed by the observable failure of the tray (the front was sheared off in a downward direction) prior to the loss of books from the tray (a two minute lag was observed between the failure of the tray front and the loss of books from the tray). This would appear to indicate that the tray failed due to water penetration as opposed to book swell (see figures 8 & 9).
After the 30 minute testing period was completed, the team was able to more fully assess the observable physical damage caused by the sprinkler deployment to the upper shelves of the array (see figures 11-14).
- The shearing effects of the downward water motion can be seen in figures 11 & 12, where the text-blocks have been macerated (leaving, in some instances, paper pulp in place of books) and the tray barcode labels have been delaminated from the front face of the trays.
- The label that was placed onto the front of the record storage box was lost and the water-soluble paper tape that held the box together was compromised during the test (see figure 13).
- Book swell was observed throughout the general collection trays – but all trays maintained their core physical integrity (see figure 14).
- Extraction of the general collections proceeded with no clear impediments (see figure 15). Trays, while noticeably tight due to book swell, were easily removed from the shelves using their handles. No general collection trays failed during the extraction process.
- The failed special collection trays were difficult to remove from the shelves. The physical integrity of the trays was noticeably compromised by the amount of water and the duration of exposure to the water.
- Removal of the archival record storage box was, additionally, challenging. This was due to the failure of the water-soluble paper tape that held together the side seam of the box. The foldered documents housed in the box were notably dry after the test (some wicking in of water at the bottom of the folders was observed).
After the materials were removed from the shelves, the trays were reweighed and photographed. The tagged books were then removed from the trays and measured, weighed (both in and out of their assigned housing, if appropriate), and photographed.
- The average dimensional expansion for a book post-test was 17.1%. This average includes both housed and un-housed volumes (housings ranged from enclosures such as phase and drop-spine boxes to rudimentary string tying of books).
- The increase in water-weight was determined, in large part, by the type of book as well as the placement of the book on the shelf. Hardcover books (which generally are constructed with more highly processed papers and have raised text-blocks) saw 26-34% increases in total weight while soft-covers increased between 51-55%. The books that were housed in trays shelved in back rows also experienced reduced water exposure.
- As would be expected, the presence of additional housing at the item level reduced the amount of water penetration by more than half.The development of a water cascade along the shelving array (resulting in reduced percent weight gain due to water penetration) was confirmed by the total calculated tray weight change. The outliers on this chart include the top shelf, which held the archival record box, and the 4th shelf of newspapers.
Recommendations and areas for future investigation
The testing confirmed that the top 5’ of shelving will experience an increased amount of damage, due to direct penetration, in the event of a sprinkler deployment. In light of the observations and assessments made above, the following recommendations can be issued:
- Whenever possible, the upper shelves (especially the 1st through 3rd) of HDS ranges should be populated with those materials that would not be severely damaged by direct water penetration or those that, once wet, would need to be kept wet while awaiting conservation treatment. These materials could include microfilm and microform formats as well as some types of digital media.
- Special collections should not be stored in the upper ranges of the HDS ladder.
- Attention should be given to the materials shelved in the back row of the first and second highest shelves of the array. These spaces will receive an increased amount of water and should be occupied, when possible, by materials that will not be inalterably damaged by prolonged water exposure.
- Labels and barcodes should either be duplicated (i.e. front and back of tray labeling) or be provided some form of additional protection from the water cascade. Observed loss of both archival storage labels and HDS barcodes could pose challenges to intellectual control over the collection material.
- The failure of the special collections trays is a cause of great concern. Attempts should be made to re-formulate either the design or the construction materials used in the manufacture of these trays to rectify this issue. If it is not possible to create trays that will stand-up to prolonged water exposure, then discussions should be made to assess the storage priorities for these types of collections.
- While the archival record storage box and folders performed well as protective barriers against direct water penetration, the box construction (i.e. use of water-soluble paper tape) was not able to be easily removed from the shelf without disturbing the contents. Record storage boxes that are to be housed in the HDS facility should be constructed with side staples and not paper tape (in order to facilitate movement from the shelf to the area of triage/assessment.
Follow-up testing: special collections housing and triage test
Participants and contributors
- University of Illinois, Urbana-Champaign (UIUC) Library, Preservation and Conservation Units: Heather Tennison, Laura Larkin, Jennifer Hain Teper, Jennifer Evers, Melissa Tedone, and Jasmeen Shorish
- Illinois Fire Services Institute (IFSI): Brian Brauer
On Monday, August 24, 2009, the UIUC Preservation Unit conducted a second live sprinkler test on a 5 foot section of high density storage shelving. The general goals of this test were to:
- Assess a beta special collection tray manufactured by Metal Edge for the purpose of this test. In response to the failed trays recorded in the April test, Metal Edge produced a series of acrylic coated special collection trays with the intention being to expose the materials to less water penetration.
- Observe the protective qualities of housings frequently utilized by the Special Collections units including:
• Record storage boxes with paper tape side seams;
• Metal Edge document storage boxes;
• Rolled storage tubes.
- Observe the potential level of water penetration into a flat file storage cabinet.
- Implement, to the extent possible, the proposed disaster recovery protocol - including, but not limited to, the triaging of materials unsuitable for stabilization through freezing.
Methods and materials
The test followed the methods and materials utilized in the first sprinkler deployment test with the following modifications:
- Data related to the overall weight of the array, either before or after the test, was not collected.
- One 5’ section of SpaceSaver Xtend Stationary High-Bay Shelving was fitted with 5 shelves (see figure 16). Shelf heights were conformance with the spacing used in the Oak Street Facility (First space/shelf – 12”; second shelf – 12”, third shelf – 12”; fourth shelf – 12”).
- One 6 drawer flat file cabinet (non-gasketed) was placed beneath the shelving array with drawer fronts flush with the front shelf edge.
- One shelf placed behind the test array was constructed so the spacing between the shelves mirrored that on the test array. Materials were placed on this back shelf to test the effect of the ‘waterfall’ on the back row trays (see figure 17).
- 10 Special collections book trays (6 beta version coated trays, 4 uncoated); 6 archival record storage boxes (all with paper tape side seam); 17 Metal Edge document storage boxes; and 4 grooved discs with paperboard covers; 4 rolled storage containers (tube in tube construction with mylar wrappings); 7 encapsulated maps; 6 half size map folders; and 5 full size map folders were prepared (documented, weighed, and photographed) for placement on the shelves (see Appendix table 3).
- ‘Problematic’ materials (i.e. various types of AV, photo, and data storage formats) were collected, tagged, photodocumented, and planted within the archival record and Metal Edge document boxes (see Appendix table 3).
- Notations were added documenting the shelf (1 being the topmost shelf, 4 being the bottommost) and the tray’s location on the shelf during testing (B = back row; F = front row; 1 = leftmost facing position, 4 = rightmost facing position upon the shelf).
- Reflective tape was adhered to the shelving unit and tested for durability in adhesion.
- The archival record storage boxes and Hollinger boxes were triaged after the completion of the 30 minute test.
- Observations were made concerning the ease with which boxes and trays were able to be extracted from the shelves and moved to the triage location.
- At the triage station, conservation and preservation staff members sifted through the record storage and Metal Edge document storage boxes to locate the ‘problematic’ materials that had been planted in folders within the boxes. Observations were made concerning the ease with which items were able to be identified and the protocol for tracking the itms and their extraction locations.
- The triaged boxes were moved to a pallett for transport. Observations were made as to the ease which which this final function transpired.
- All test activities were photo-documented.
The first tray failure (first shelf, first position – acrylic coated test tray) was observed at 5:33 minutes into the 30 minute test. As was observed in the first test, tray failure appeared to be due to an inherent mechanical weakness in the tray material (as opposed to bookswell) as the first book did not fall from the tray until 6:49 minutes into the test (over a minute later). The second tray failure occurred at 8:07 (second shelf, third position – coated test tray).
The third failed tray was observed at 9:16 as one of the back shelf trays gave to book swell (these back trays were experiencing the waterfall that formed when the high pressure water was pushed off of the top most ‘roof’ shelf of the front array (see figure 18).
The regular special collections trays (i.e. uncoated) failed at the 12:39 mark (fourth shelf, fourth position) and at 16:29 (third shelf, second position). The timing of the two uncoated special collection failures was similar to those observed during the first sprinkler deployment test.
The final tray failure (back shelf) occurred at 18:12, again due to book swell.
After the 30 minute testing period was completed, the team was able assess the observable physical damage caused by the sprinkler deployment.
- The shearing effects of the downward water motion can be seen in figures 19 & 20 where, like in the first test, the text-blocks have been macerated.
- Record and Metal Edge document storage boxes in the font facing positions of the shelving array were observed to have, in some instances, lost their barcode, their collection label, or both.
- The water-soluble paper tape side seams found on the record storage boxes failed uniformly, making extraction, triage, and palletization difficult if not impossible to accomplish without damaging the materials (or the order of the materials) inside (see figure 21).
- Book swell was observed in all of the special collection trays (both failed and intact)
- The special collection trays that were shelved in the back row and therefore did not actively fail during the 30 minute test were generally weakened by the water exposure and could not be extracted from the shelves by the handle.
- The Metal Edge document storage boxes were able to be easily extracted, triaged, and palletized without incident
- Due to an active leak at the bottom pipe connection adjacent to the flat file, any observations related to the seepage of water into the flat file cabinets cannot be analyzed. The amount of water that was found and the amount of damage caused to the folders and documents within the drawers was more likely due to the active spurting of water from the connection location than from the sprinkler cascade.
- Triage of ‘problematic’ materials from the Metal Edge document storage boxes and record storage boxes was, in general, a smooth process. One individual was able to quickly sort through the boxes; identify materials to be extracted; pull the materials from the box; bag and tag the materials; place a duplicate barcode (on the edge of a mylar strip) into the extraction location (to maintain original order); and place the extracted material into one of three bins representing photographic materials, AV media, and data storage.
- Materials housed in the rolled storage were adequately protected by their mylar covering and suffered no damage. Red ink stamps located on the inside wrapping of the tubes was noted as being highly water soluble, so care should be taken when handling these housings.
- After the materials were removed from the shelves, but before they were triaged, the boxes and trays were weighed. Books that had fallen during the test were placed within a bin and weighed as a whole. There was a 45% total weight gain (due to water) among all materials (here 1=weight before the test and 2=weight after).
- The amount of water penetration was greatest at the second shelf (which is in line with observations made during the first test). The higher percentage of penetration on the fourth shelf, as compared to the third, can be explained by the material types that were shelved in the different locations. Overall, the percentages are quite low and are indicative of the protection offered to the collections through the Metal Edge document boxes and record storage boxes (the exclusion of failed tray data from the calculations may also have had an effect on the results). Breakouts of tray, Metal Edge document storage boxes, and record storage boxes echoed the overall shelf total percentage gained.
Recommendations and areas for future investigation
- The application of an acrylic coating to the special collection tray construction materials did not increase the stability of the trays. While the acid-free/lignin-free qualities of the trays are ideal for the long-term storage of rare books and special collections, the fact that in the event of a water disaster these trays will most certainly fail is a cause of concern. Due to the high quality of the environment found in the HDS facility, the negative impact of the general collection trays may not be as detrimental as would be expected in a less climate controlled environment. Curatorial and preservation staff should reconsider the use of general collection trays for the storage of all special collection materials.
- The unique coloring of the special collection trays has been a factor in facilitating the identification of some special collection materials. If all collection materials are to be shelved in ‘general collection’ trays, a mechanism will need to be put in place to assist in the identification of special from general collection materials. Investigations should be made into the application of colored label savers. Use of tinted label savers would serve the dual function of identifying special collection trays and protecting barcodes (and archive labels) from water damage in the event of a sprinkler deployment.
- The failure of the paper-tape side seams on the tested archival record storage boxes was an additional cause for concern. The tape failure completely undermined the structural stability of the box construction and made the safe extraction and triage of these materials excessively difficult. All record storage boxes that are sent to the Oak Street Facility for storage should have side-staple seams (not paper-tape).
- The quick identification of ‘problematic’ materials stored in record and Metal Edge document storage boxes is will be a high priority for triage staff in the event of a large scale water disaster. A sticker/label that identifies that there is (or is not) AV, photographic, and/or data storage media present in the box should be developed with the special collections curators for use on ALL closed boxes.
- While the flat file portion of the test was inconclusive, the need for a large cart with which the safe retrieval of the flat file materials could be accomplished was noted. Additionally, a discussion should be instigated with BMS to determine how they would handle the transport and storage of oversized flat files in the event of a disaster at the HDS facility.
Table 1: First test – tray data
Table 2: First test – Tagged book data
Table 3: Special Collections Housing test