By Bill Adams
There are nine domestic manufacturers of custom cabs and chassis for the fire service. Four are owned by one corporation. None were formally asked to participate in this narration, nor were manufacturers that fabricate “raw” custom cabs for apparatus manufacturers, nor were the manufacturers of complete commercial cabs and chassis used by the fire service.
Five years ago, my article “Apparatus Purchasing: Custom Cabs Part 2, the Safety Standards” in Fire Apparatus & Emergency Equipment” (March 2017) addressed safety standards applicable to fire apparatus custom cabs and chassis. In it, questions were raised worthy of further discussion. That time is now.
Fire apparatus crash testing is a serious topic deserving serious attention. It addresses occupant survivability in a fire apparatus cab that may be involved in an accident. National Fire Protection Association (NFPA) 1901, Standard for Automotive Fire Apparatus, does not address crash testing in depth. As an example, NFPA 1901, Chapter 14, Driving and Crew Areas, Section 14.3 devotes almost 1,300 words, several illustrations, and a chart to “seat belts” and only 91 words to the crashworthiness of the apparatus cabs—including the tiller cab on tractor-drawn aerial ladders (TDAs).
It is frustrating not to receive straight answers when asking simple questions. Over the years, my questions posed to fire service vendors about crash testing should have elicited yes, no, or I don’t know answers. Some resulted in a 20-minute obfuscation resulting in total confusion and bewilderment. Obfuscate means to obscure, disguise, or even conceal. In firehouse talk, it means to beat around the bush. Some vendors dodged answering. Others did not know the answers but would not admit it. There are times when simple answers may need clarification, but not all the time and not always about the same subject.
NFPA 1901
It is disingenuous to claim crash testing exceeds the NFPA’s level of expertise. The 30 members of its Technical Committee on Fire Department Apparatus cannot be expected to be “experts” on every facet, nut, and bolt of fire truck construction and operation. Consequently, it references almost 100 publications and standards promulgated by numerous professional organizations. NFPA 1901, Chapter 2, Referenced Publications, sentence 2.1: “The documents or portions thereof listed in this chapter are referenced within this standard and shall be considered part of the requirements of this document.”
Fire departments should acknowledge and respect the NFPA’s willingness and commitment to seek outside expertise. However, both the NFPA and the manufacturers that must comply with 1901 should be capable of answering basic questions about its requirements. Manufacturers ought to know what they are required to “comply” with.
NFPA 1901, Section 4.3, Driving Compartment denotes the “standards” cabs have to meet but does not say why. Addressing the “survivability” of firefighters in the event of a crash warrants some mention.
Crash Testing Standards
The research and accumulation of data pertaining to survivability in vehicles with more than a 26,000-pound gross vehicle weight rating (GVWR) have already been done by other entities. From the aforementioned article: “Publications with a ‘J’ designation are published by the Society of Automotive Engineers (SAE), a professional group founded in 1905. From its Web site, ‘SAE standards are internationally recognized for their role in helping ensure the safety, quality, and effectiveness of products and services across the mobility engineering industry.’”
Two SAE J standards, along with a related United Nations (UN) document, are referenced in NFPA 1901, sentence 14.3.2: “Cabs on apparatus with a GVWR greater than 26,000 lb (11,800 kg) shall meet the requirements of one of the following sets of standards: SAE J2420, COE Frontal Strength Evaluation—Dynamic Loading Heavy Trucks; SAE J2422, Cab Roof Strength Evaluation—Quasi-Static Loading Heavy Trucks; and ECE Regulation number 29, Uniform Provisions Concerning the Approval of Vehicles with Regard to the Protection of the Occupants of the Cab of a Commercial Vehicle.”
The J2422, J2420, and ECE 29 criteria were not created solely for American fire service custom cabs. They were developed specifically to provide survivability for occupants in all large commercial vehicles. The SAE and the UN did all the research and legwork. The NFPA just tagged on—a smart move.
The NFPA has gone on record stating custom cabs designed specifically for the fire service probably exceed the crash testing criteria for other large commercial vehicles. In Appendix A, sentence A.4.13.1: “The nature of the custom fire apparatus cab makes it much stronger in rollover than typical conventional commercial chassis cabs. There is much anecdotal evidence to indicate that the crashworthiness of a typical custom fire apparatus cab is significantly greater than a typical commercial cab, and most custom chassis manufacturers can provide test data on cab integrity.”
I researched the domestic cab and chassis manufacturers’ Web sites for crash data testing information. It varies. One, from Pierce Manufacturing, was very specific in addressing the topic and is worth reading: https://www.piercemfg.com/pierce/blog/fire-truck-crash-testing-crashworthiness.
Updates?
The NFPA normally updates the 1901 standard about every five years. The J2422 and J2420 standards were issued January 1, 1998. Both were revised in 2003 and again in 2010. The 2003 revision was the first where testing criteria was established. I venture many commercial vehicles with a minimum 26,000-lb. GVWR have crashed since 2003.
From the Insurance Institute for Highway Safety (IIHS) Web site (https://www.iihs.org/topics/large-trucks#by-the-numbers): “A total of 4,119 people died in large truck crashes in 2019. Sixteen percent of these deaths were truck occupants …. The number of people who died in large truck crashes was 31 percent higher in 2019 than in 2009, when it was the lowest it has been since the collection of fatal crash data began in 1975.” Note that these figures are for all large trucks and not specifically fire apparatus. Fire service-related organizations such as the Fire Apparatus Manufacturers’ Association, the International Association of Fire Chiefs, and the International Association of Fire Fighters may have specific crash data on firefighter deaths and injuries.
Deaths and injuries are not mentioned to claim cabs are unsafe. They are to illustrate that data on cab safety has been accumulated. The Department of Transportation’s National Highway Traffic Safety Administration (NHTSA) has multiple Web sites with substantiating analytical data going back decades. Need more info? Use your computer’s search engine and enter “How many class 8 truck accidents are there per year in the United States?”
It stands to reason if the crash data accumulated over the past decades has been analyzed, the J2422 and J2420 testing criteria “could have been updated.” Have they? If I’m spending a half-million dollars for a fire truck, whoever I am buying it from ought to know. Do they?
The ECE 29 standard is not being addressed. According to NFPA 1901’s Annex, sentence A.14.3.2: “The U.S. standards developed by SAE and the United Nations ECE regulation mirror each other except that SAE J2422 requires a roof preload impact prior to the roof crush. The ECE standard was established in 1958, while the SAE standards did not add performance criteria until 2003. Both the SAE and ECE standards are viable minimum measures of cab integrity. Manufacturers may test in excess of the standards.” Some have, according to their advertisements.
Testing and Certifying
NFPA 1901, Chapter 4, General Requirements, sentence 4.20.1 lists the documentation that must be provided with each new apparatus. Twenty “certifications” are required. I cannot find if NFPA 1901 requires crash testing compliance to be certified by an independent third-party organization or by the manufacturer of the cab.
Regardless, when certification is mandated by NFPA 1901, it must follow a myriad of requirements under Chapter 4, Section 4.4, Responsibility of the Contractor. NFPA 1901 does not state apparatus manufacturers cannot test the cabs themselves. It just says the cabs will be tested. Are testing and certifying your own product similar to having the fox guard the henhouse?
Determining who tests and who certifies NFPA requirements is confusing. As an example, under Aerial Devices, sentence 19.24, Certification Tests, it states: “The completed apparatus with the aerial device shall be tested to the criteria defined in this section and the test results certified by an independent third-party certification organization.” It does not say who does the testing.
Conversely, some testing on fire pumps has to be witnessed by an independent third-party organization (sentence 16.13.1.1.5) and the test results certified by the apparatus manufacturer (16.13.1.2.4*). The appendix also notes that the purchaser might “wish” to have the test results certified by the third-party organization.
It is unknown if the testing and certification criteria for fire pumps or aerial devices would be the precedent the NFPA might, or could, follow for requirements such as crash testing.
Questions
- Do ECE 29 or the J tests ever expire or have to be renewed?
- Are there fire department exemptions for ECE and J series testing criteria?
- Do OEMs who offer multiple raised roofs have to test each one?
- On some raised roofs, windows are often cut into the front and sides of the raised portion. Does that structurally change the cab where it may require retesting?
- If an OEM structurally alters the actual width of a cab, does it have to be retested?
- Some OEMs lower where the motor sits on/in the frame rails. Is that a change in the cab’s structural design that would require retesting?
- One criterion when testing cabs is that the cab doors cannot “pop open” when the cab is tested. If an OEM changes its door latch mechanisms, does the cab have to be retested?
- Do both full-height doors and barrier-style doors have to be tested?
- Does a cab with a door full height to the top of a 24-inch raised roof have to be tested?
- Has testing criteria ever been modified based on crash results from the field (accident investigations)?
Firefighter safety including survivability inside a fire apparatus cab involved in an accident is important. Asking the particulars of crash testing is not questioning the intent of safety standards, nor is it doubting the expertise of manufacturers or regulatory agencies. It is to educate the firefighter in the value of and how NFPA 1901 is specifying a safe environment inside the apparatus cab
BILL ADAMS is a member of the Fire Apparatus & Emergency Equipment Editorial Advisory Board, a former fire apparatus salesman, and a past chief of the East Rochester (NY) Fire Department. He has 50 years of experience in the volunteer fire service.
