By Bill Adams
Raisin Squad kibitzing in the firehouse kitchen was the original theme for this column. However, it morphed into another of my favorite topics: non-compliance to, and not understanding, the National Fire Protection Association NFPA 1901 Standard for Automotive Fire Apparatus. One geezer accused me of being anti-NFPA. Another said whenever I query the NFPA it’s like I’m abusing a rented mule. It’s not intentional.
A friend asked me to evaluate his purchasing specifications for a new rig. We both know he writes specs around one manufacturer. We’ve played this game before. It’s our way to keep in touch, talk fire trucks, and swap firehouse gossip. Well, what do you think about them? he asked. That was a mistake. (All underlining mine for emphasis.)
One specification requirement was: “The apparatus shall be designed with due consideration to distribution of load between the front and rear axles. Weight balance and distribution shall be in accordance with the recommendations of the National Fire Protection Association.” There’s no problem with that requisite although it was like ripping a scab off a healing wound. However, it gave me an opportunity to bloviate. Bloviate means “to discourse at length in a pompous or boastful manner.” Old people do it quite often.
Another requirement was: “The bidder shall make accurate statements as to the apparatus weight and dimensions.” It was like the 1993 movie Groundhog Day—I addressed front-to-rear weight distribution ratios 10 years ago in a Fire Engineering article.
I already knew the answer but still inquired if this was the same specification used for his last purchase. It was. When asked if that previous manufacturer provided a front-to-rear weight ratio, he couldn’t remember but acknowledged the bidder said the rig was NFPA compliant. I was off and running! What the hell kind of answer is that? You’re buying a rig that’ll cost almost a million bucks and you don’t know what’s in the specs? How can you evaluate a bidder’s compliance to the chassis manufacturer’s front-to-rear weight ratio if he doesn’t tell you what it is? If you get more than one bid, how do you compare something you can’t define–or find? I think he knew I was just teasing. We kibitzed some, told a few more tall tales, and parted friends.
NFPA 1901
I believe most specification writers and fire apparatus and chassis manufacturers will not or can not accurately describe front-to-rear weight ratios. What are they? Are they in writing? Where can I find them? That isn’t asking too much.
Actual NFPA 1901 requirements should be acknowledged. Again, underlining is mine for emphasis. NFPA 1901 4.13.2 Weight Distribution, sentence 4.13.2.1*: “When the fire apparatus is loaded to its estimated in-service weight, the front-to-rear weight distribution shall be within the limits set by the chassis manufacturer.” It is important to note the weight distribution ratio is set by the chassis manufacturer—not the apparatus manufacturer. And, it isn’t a recommendation as my friend’s specification said.
NFPA 1901 Appendix, sentence A.4.13.2.1 explains why maintaining a safe front-to-rear weight ratio is important: “The distribution of the weight between the front wheels and the rear wheels should be a major consideration, because improper design will seriously affect the handling characteristics of the fire apparatus. Too little weight on the front wheels can cause a front-end skid and, on bumpy roads, can cause the front of the fire apparatus to veer from side-to-side. At the very least, it would be