Dark clouds build ominously on the horizon as the workers finish a large tent installation. Strong winds and heavy rain are forecast. The local fire marshal arrives to issue the necessary permit and eyes the ballast skeptically. A storm is on the way—will the tent hold?
Are you sure?
Michael Tharpe, Chairman of the Tent Rental Division (TRD) explains that this is a common question that rental operators are faced with from the local authority having jurisdiction (AHJ). “Since the initiation of our original ballasting tool, it became pretty evident that we (TRD) needed to carry this a step further and include non-engineered products as well. After years of study and development of this new tool, we can confidently answer this question, ‘Yes, we are sure!’”
“Permitting and dealing with code officials can be daunting and intimidating,” says Dan Hooks, board chair of the American Rental Association (ARA) and TRD member. “When a fire marshal looks to you for guidance on the proper installation of your tent and you don’t have definitive information to provide them, it does not give them confidence to approve the installation and they may demand more ballasting just to be safe. This is not a situation where you want to be relying on some arbitrary rule of thumb.”
The question of how much ballast is necessary to safely secure a tent is one that tent rental companies have been struggling with for decades. Most newer tents are certified by engineers to require a set amount of ballast. But there are still many—particularly older tents or tents that have been modified from their original design—that do not have the corresponding documentation that can be used as a guideline for installers, but also shown to local code officials as verification that the structure has been properly secured.
“My company has tents that came from back in the 80s,” says Alex Renaud, a TRD board member and Advanced Textiles Association (formerly IFAI) code committee chair. “They’re old but they’re still really good tents. This industry has lots of members who have that sort of usable inventory, but they don’t have any engineering calculations for them, so in order to obtain a permit, you have to hire an engineer.”
Recognizing this problem, the TRD and the ARA each independently began working on a solution for their members. “When ARA discovered IFAI [now ATA] was already working on this problem, we decided it would be best to create a partnership and come up with a joint solution so that we can be consistent as an industry,” explains Hooks. “We wanted to have one voice. That’s one of the biggest challenges we face—there’s no good empirical data out there on this, so having one voice instead of several is key.”
ATA’s president Steve Schiffman agrees. “This is a valuable tool that will prove tremendously useful to both TRD and ARA members. Partnering on its creation was the right decision to eliminate any potential confusion and ensure everyone in this industry is using the same data.”
Over the course of three years, committee members from the two associations worked together to develop a non-engineered ballasting tool (NEBT) that utilizes factors such as surface type, ballast type, surface condition, horizontal and vertical reaction force, distance from center of ballast to center of upright and diameter of ballast in determining the guidelines for required weight to meet the manufacturer’s specified load. By using generic geometry and load assumptions, the tool can provide installers and code officials with a best estimate of reactions for non-engineered tent models.
“This tool allows our members to key in certain parameters—the type and size of the tent, wind load requirements, type of ballast being used and on what type ground—they put all the information into the ballasting tool and get an accurate estimate of the ballasting required to meet those specifications,” explains Tharpe. “They can then print out those specifications and use them to obtain permitting.”
Of course, as with any calculations, the figures this tool generates are only as accurate as the information an installer provides. The NEBT website notes that the results generated are “best conservative estimations” based on general engineering concepts. The proper anchoring or ballasting for safe tent installations ultimately remains the sole responsibility of the installer.
However, Renaud says installers can be confident in the NEBT’s estimations. “The tool generates a result that falls on the safer side of cautious. We could have made a tool that gave you the LEAST amount of weight you needed, going right to the limit of safety. But because we’re giving results for several different models, we made it much more conservative in its estimates.”
Now, when the local AHJ comes to a job site, a tent installer can present the specifications generated by the NEBT and the code official has a way to verify that the tent has been secured according to industry guidelines.
“This is a great tool that combines an engineering perspective alongside the manufacturer input so we can come up with some good data for the industry to give to the fire marshals,” says Hooks. “If a fire marshal walks up, we can show them the tool and how much weight the tent needs given the set of conditions. It’s not any one of us going out on a limb saying we know if we put 5,000 pounds of ballast on this leg, it will withstand a 90 mph wind. It will also keep anyone from thinking that using a few water barrels constitutes industry best practices.”
Ensuring the safety of every employee and guest who enters a tent is the primary focus of this industry. Whether someone has decades or days of experience installing tents, no one should have to guess how much ballast is required and just hope for the best. That’s how companies end up on the nightly news, and bad publicity for one company is bad for the whole industry.
“Standardizing and promoting the use of best practices to prioritize safety is a huge win for the entire industry,” says Schiffman. “We’re delighted that the partnership with ARA has resulted in a tool like this now being freely available to members of both associations.”
TRD members can find out more information and access the NEBT online at tent.textiles.org/resources/TRD-ballasting-tools.