Interpretation ID: nht75-3.16
DATE: 12/24/75
FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA
TO: Truck Body and Equipment Association Inc.
TITLE: FMVSR INTERPRETATION
TEXT: I would like to acknowledge receipt of the Truck Body and Equipment Association's (TBEA) December 2, 1975, request that the applicability of Standard No. 121, Air Brake Systems, to fire fighting vehicles be delayed until January 1, 1977.
The NHTSA has decided to grant the TBEA request, and has issued a notice of proposed rulemaking to establish a September 1, 1977, effective date for these and several other categories of vehicles. A copy of the proposal is enclosed for your information.
You should understand that our publication of a proposal in this area does not signify that a final rule will be issued. A decision as to the issuance of the rule is made on the basis of all available information developed in the course of the rulemaking proceeding, in accordance with statutory criteria.
I would like to remind the TBEA that a recent amendment of NHTSA rulemaking procedures provides that a request for rulemaking will only be considered as a petition for rulemaking if, among other things, it includes a heading preceding the text, that includes the word "petition" (49 CFR @ 552.4(b)).
Yours truly,
Enclosure
December 2, 1975
Administrator -- National Highway Traffic Safety Administration
Dear Sir,
On November 11, 1975 the NHTSA proposed to temporarily withdraw certain sections of FMVSS 121 as they apply to a bus manufactured before January 1, 1975. The reasoning cited to support this proposal centered on data collected at the NHTSA's FMVSS 121 Hearings of October 27-29, 1975. These hearings resulted in the following findings:
1. Manufacturers of both transit and intercity buses do not appear prepared at this time to utilize antilock systems other than those manufacturered by Rockwell International Corporation.
2. The Rockwell antilock system currently available for bus application is characterized by malfunction the warrants its deactivation on all vehicles on which it is installed while a correction is fully developed.
3. Information furnished by Rockwell does not provide a basis to conclude that a demonstrably satisfactory correction to its antilock system defects is at hand.
4. A situation wherein purchasers of new buses are required to pay for antilock systems which are to remain deactivated for an indefinite period is inappropriate.
The compliance problem seems to be focused on the bus manufacturers sole dependence on the unreliable Rockwell International axle and anti-wheel-lock system.
We at TBEA and especially the Fire Apparatus Manufacturers Division (FAMD) have taken a keen interest in the final outcome of this proposal. The custom fire apparatus industry is also effected by a singular dependence to the Rockwell System.
Fire Apparatus are generally broken down into two different categories: "Commercial Apparatus" - Those built on a commercial truck chassis ie: Ford, Chevrolet, International, and "Custom Apparatus" - Those built from the ground up. The present industry split is 60% and 40% in favor of commercial over custom apparatus. Based on a projected five thousand (Illegible Word) per year this split equates to three thousand commercial and two thousand custom pieces of fire apparatus.
Just as in the bus manufacturing market, Rockwell International has the custom fire apparatus to itself. The manufacturers of fire apparatus are presently beginning to build full FMVSS 121 equipped vehicles even though the standards effective dates for fire apparatus and special permit vehicles are three and nine months off.
There is deep concern within this industry as to the reliability of this yet to be proven anti-wheel-lock system on emergency vehicles. The operating mode of a fire truck is drastically different from a conventional truck. Rather than normal stops and starts, a fire truck must rapidly accelerate and decelerate over a short response time. Any failure of the electronic monitoring anti-wheel-lock system when used in conjunction with FMVSS 121 high torque brakes could result in a dangerously unstable vehicle.
The poor quality of anti-wheel-lock hardware available to the bus manufacturing industry has lead the NHTSA to propose a temporary withdrawal of the existing anti-wheel-lock and stopping requirements of FMVSS 121 as they relate to buses. This delay will afford those manufacturers with the time to collect real world experience with the anti-wheel-lock equipment.
The fire apparatus industry is not presently required to comply with FMVSS 121. The effective dates required for compliance range from March 1, 1976 - fire apparatus, September 1, 1976 - special permit vehicles (24,000 pound GAWR) to never - special permit vehicles (29,000 pound GAWR).
The FAMD wishes to petition the NHTSA to allow this industry the same consideration given the bus manufacturers, by withdrawing the stopping distance and anti-wheel-lock requirements for fire apparatus until January 1, 1977.
The amendment would allow the fire apparatus industry to proceed with the following: 1. Commercial fire apparatus built on FMVSS 121 truck chassis would continue to provide real world data reflecting the interaction of the commercial anti-wheel-lock systems on fire apparatus.
2. Custom fire apparatus could be built with FMVSS 121 hardware based on the availability of components. Those units produced with the Rockwell System could be carefully monitored during this grace period.
This grace period would also provide the industry with the following:
1. Opportunity to phase-in and monitor the new anti-wheel-lock equipment.
2. Reduce existing surplus inventory of non FMVSS 121 axles and suspensions.
3. A uniform effective date (January 1, 1977) would be established for fire apparatus provided that the hardware was improved sufficiently to warrant it.
We at the FAMD urge the NHTSA to consider these facts prior to the current FMVSS 121 effective date of March 1, 1976 for fire apparatus.
Very truly yours, Byron A. Crampton -- Manager of Engineering Services,
TRUCK BODY AND EQUIPMENT ASSOCIATION, INC.