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Safety Recommendation Details

Safety Recommendation H-02-022
Details
Synopsis: On May 31, 2001, about 3:28 p.m. central daylight time, a southbound Gayle Stuart Trucking, Inc., truck-tractor semitrailer exited Interstate 540 at State Highway 282 (SH-282) near Mountainburg. The driver was unable to stop at the stop sign at the bottom of the ramp. The 79,040-pound combination unit was traveling approximately 48 mph when it entered the intersection and collided with the right side of a westbound, 65-passenger, 1990 Blue Bird Corporation school bus operated by the Mountainburg, Arkansas, Public Schools. The school bus rotated approximately 300 degrees clockwise and overturned; the body, which partially separated from the chassis, came to rest on its right side on the eastbound shoulder of SH-282. The tractor semitrailer continued across the roadway, rotated about 60 degrees clockwise, overturned, and came to rest on its left side. Three school bus passengers seated across from the impact area were fatally injured; one was partially ejected. Two other passengers, one of whom was seated in the impact area, received serious injuries, and four passengers had minor injuries. The school bus driver and the truckdriver both sustained minor injuries.
Recommendation: TO 5 SPRING BRAKE MANUFACTURERS: Develop a spring brake that allows inspectors or mechanics to view components safely to determine whether the spring is broken.
Original recommendation transmittal letter: PDF
Overall Status: Open - Await Response
Mode: Highway
Location: Mountainburg, AR, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: HWY01MH025
Accident Reports: Collision Between Truck-Tractor Semitrailer and School Bus
Report #: HAR-02-03
Accident Date: 5/31/2001
Issue Date: 9/13/2002
Date Closed:
Addressee(s) and Addressee Status: Bendix Commercial Vehicle Systems, LLC (Closed - Reconsidered)
Carlisle Motion Control Industries, Inc. (Closed - Reconsidered)
Haldex Commercial Vehicle Systems, Inc. (Open - Await Response)
Indian Head Industries, Inc. (Closed - Acceptable Alternate Action)
TSE Brakes, Inc. (Closed - Acceptable Alternate Action)
Keyword(s):

Safety Recommendation History
From: NTSB
To: TSE Brakes, Inc.
Date: 6/13/2014
Response: Although we understand that you did not develop the recommended spring brake that allows a view of the components, we are pleased that you developed a brake stroke monitoring system that can inform drivers, inspectors, and mechanics of the proper functioning of a vehicle’s brake system. We note that your brake monitor works on both traditional s-cam foundation brake and air disc brake actuators, and can be fitted to TSE and other brand systems. These actions constitute an acceptable alternate means of addressing Safety Recommendation H-02-22, which is classified CLOSED—ACCEPTABLE ALTERNATE ACTION. We commend you for your efforts, as they also support recommendations that we made subsequently as a result of our investigation of a truck-tractor collision with a train at a grade crossing in Miriam, Nevada, recommending that the National Highway Traffic Safety Administration develop performance standards for, and require installation of, onboard brake monitoring systems for all newly manufactured air-braked commercial vehicles. Thank you for your commitment to improving commercial vehicle brake safety.

From: TSE Brakes, Inc.
To: NTSB
Date: 4/25/2014
Response: -From Wade Roskam, President, TSE Brakes: NTSB issued recommendation H-02-22 on September 13, 2002 requesting that Spring Brake Manufacturers develop a spring brake that allows inspectors or mechanics to view components safely to determine whether the spring is broken. TSE Brakes detailed in a letter of October 7, 2002 (copy attached) the difficulty in developing such a design while maintaining the current safety features of a spring brake. TSE Brakes suggested an alternative method utilizing a paint mark on the service push rod to detect full spring retraction and therefore proper spring function. Subsequent to that correspondence, TSE was acquired by Marmon Highway Technologies, and I assumed the presidency of this business. Until your follow letter of February 10 2014, TSE was unaware of your request for updated information. Please accept our apologies for the lengthy interim period between responses. As a reminder, the Society of Automotive Engineers recommended practice J1953 is supported by FMVSS regulation 517.121-S5.2.2 currently requires the service push rod to have a mark that indicates over-stroke or out of adjustment brakes. After reviewing the TSE Brakes recommendation letter of October 7, 2002 we find the following practical disadvantages: -We believe placing another mark on the service brake push rod to indicate full retraction, in addition to the current mark, will result in confusing mixed messages for driver, maintenance technicians and inspectors. -This solution is only applicable to one type of brake actuator: the s-cam foundation brakes actuator used only for drum brake equipped vehicles. Since 2002, the production of air disc brake equipped vehicles has increased, partially as a response to NHTSA's revised stopping distance requirements per FMVSS regulation mentioned above and released in August of 2011. TSE Brakes has continued to develop improved safety features on our products and has recently begun field testing an alternative design brake stroke monitor that meets the intent of NTSB H-02-22. This device is located at the parking side of the spring brake chamber and is affixed to the pressure plate which is acted upon by the main spring. When the spring brake is released, this assembly engages the service push rod and indicates whether the brake is over-stroked or out of adjustment as the service push rod mark does today. By relying upon spring actuation for the inspection, there is the added benefit of ensuring the main spring is functioning properly. This device provides simple visual confirmation to drivers, technicians or inspectors of the brake actuator stroke capability and requires no tools or measuring devices to confirm compliance. This device can be utilized in both traditional s-cam foundation brake actuators as well as air disc brake actuators. Finally, this stroke indicator can be fitted and used on both TSE and other brands of air brake actuators. TSE has applied for a patent for this device and is willing to explain the operation and benefits further to the NTSB. We believe this new device can provide for a simpler inspection process, leading to clear 11in service", "out of service" decision making by owners, drivers, and/or inspectors. We believe this will ultimately lead to safer truck and trailer equipment on our road network Please let us know if the NTSB would like to discuss further details.

From: NTSB
To: TSE Brakes, Inc.
Date: 2/10/2014
Response: We last received a letter regarding this recommendation from your company in October 2002. At that time, TSE Brakes offered an alternative solution to address this recommendation by suggesting that spring brake manufacturers provide markings on service brake push rids to indicate normal retraction. On December 17, 2003, Safety Recommendation H-02-22 was classified OPEN—ACCEPTABLE ALTERNATE RESPONSE pending our receipt of a written update indicating that your spring brakes had been modified as suggested. We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others. Therefore, please inform us about the progress of your actions to implement Safety Recommendation H-02-22.

From: NTSB
To: TSE Brakes, Inc.
Date: 12/17/2002
Response: The Safety Board acknowledges that verifying full retraction capability of the push rod will allow inspectors or mechanics to view components safely to determine whether the spring brake is properly functioning. This complies with the intent of the recommendation. Pending receipt of a written update from TSE indicating that their spring brakes have been modified as described above, Safety Recommendation H-02-22 is classified OPEN -- ACCEPTABLE ALTERNATE RESPONSE.

From: TSE Brakes, Inc.
To: NTSB
Date: 10/7/2002
Response: Letter Mail Controlled 10/16/2002 11:17:31 AM MC# 2020865 - From Ted Smith, President: NTSB stated that "The design of brake springs makes detection of broken springs difficult because access to the closed chamber is restricted". In other words, spring brake manufacturers have been successful in achieving their goals of avoiding liability and still providing a high energy product that is safe to handle. I am not aware of a spring brake design that will retain the safety features we all know are needed, and at the same time, achieve this new recommendation of NTSB to "view components" such as fractured main springs. However, I would like to respectfully suggest an alternative solution. It seems to me that main spring fracturing within a spring brake may be a contributor to the problem you have described, but it is not the actual problem. The actual problem is that the push rod is unable to fully retract within a spring brake. Such a partial retraction reduces application stroke for both the service and emergency sections of a spring brake, depending upon the pile up of fractured main springs or other stroke interferences. In my opinion, what the inspector really needs to know is that push rod retraction travel meets manufacturers specifications. With air pressure be fully retracted within the emergency section, road operation ready, the push rod must be fully retracted if full stroke capability is to be achieved. I believe a visual inspection, on the vehicle, with focus on push rod travel, will be helpful toward verification of full push rod retraction. Many spring brake manufacturers provide, or could provide, painted or otherwise marked service brake push rods that clearly indicates normal push rod retraction. If the indicator, or mark, on the push rod is flush with the non pressure housing service brake mounting base surface, full retraction is achieved. This is how the inspection could be conducted: 1. Wheels chocked. The emergency parking system and the service brake application must both be in the released or drive configuration. 2. Inspector visually inspects each push rod for proper retraction. Many types of retraction indicators are available. My comments above relate only to those air brake actuators that have full stroke retraction indicators. For vehicles with actuators not equipped with full retraction indicators, full retraction inspection is feasible, but the process will be more time consuming and complex. Generally, in order to inspect a service brake push rod for full 2.5 inch or 3.0 inch push rod travel if the push rod has no appropriate stroke retraction indicator, the clevis must be fully disengaged allowing full and unrestricted travel of the push rod. With the clevis disengaged, maximum and minimum positions, under application or fully released, would be measured to determine stroke capability. Thus, full retraction capability could be verified.

From: NTSB
To: Bendix Commercial Vehicle Systems, LLC
Date: 3/20/2003
Response: Your letter indicates that BCVS is a leading supplier of air brake and control systems, components, and leading-edge technologies for medium-duty and heavy-duty trucks and other commercial vehicles. Your letter further states that current BCVS products, such as the DD-3 actuator, may at some future point become a commonly used alternative that meets the mechanical park requirement. Further, the Safety Board understands that the BCVS DD-3 is technology that has been in use for over 40 years, mostly in motorcoaches, but that can also be used in all types of heavy commercial vehicles. In response to Safety Recommendation H-02-22, your letter indicates that BCVS has completed a preliminary engineering feasibility study and has determined that a visual inspection of the components may not be a practical solution, due to structural and environmental conditions. The Safety Board appreciates your feedback, and recognizes that your DD-3 actuator is a double diaphragm air-applied/mechanically held product that does not use a power spring to hold the vehicle on a grade. Due to the absence of a spring, your product does not have the problem described in Safety Recommendation H-02-22. In addition, by suggesting that the DD-3 actuator be used as an alternate to the spring brake, BCVS does provide an alternate solution to the problem that resulted in Safety Recommendation H-02-22. As a result, Safety Recommendation H-02-22 to BCVS is classified CLOSED -- RECONSIDERED.

From: Bendix Commercial Vehicle Systems, LLC
To: NTSB
Date: 12/9/2002
Response: Letter Mail Controlled 12/17/2002 5:45:25 PM MC# 2021029 - From James W. Szudy, Engineering Manager: In response to the NTSB's request, BCVS has conducted a preliminary engineering feasibility study pursuant to which BCVS has developed some concepts. In the course of our study, we have determined that a visual inspection of the components may not be a practical solution due to structural and environmental considerations. BCVS would like to bring to your attention a current product that would eliminate the power spring used to meet the mechanical park requirement. The DD-3 actuator is a double diaphragm air applied/mechanically held product that does not use a power spring to hold the vehicle on a grade. The mechanism locks the push-rod shaft after it is extended. An additional advantage of the DD-3 is that parking force and emergency brake force on trucks and buses would be greater as it would not be limited to the power spring design constraints. The design of the parking brake control system would have to be changed due to current FMCSA and NHTSA requirements.

From: NTSB
To: Indian Head Industries, Inc.
Date: 4/23/2014
Response: Although we understand that you did not develop the recommended spring brake that allows a view of the components, we are pleased that you developed an electronic brake stroke monitoring system that can inform drivers, inspectors, and mechanics of the overall health of a vehicle’s brake system. These actions constitute an acceptable alternate means of addressing Safety Recommendation H-02-22, which is classified CLOSED--ACCEPTABLE ALTERNATE ACTION. We commend you for your efforts, as they support recommendations that we made subsequently as a result of our investigation of a truck-tractor collision with a train at a grade crossing in Miriam, Nevada, recommending that the National Highway Traffic Safety Administration develop performance standards for, and require installation of, onboard brake monitoring systems for all newly manufactured air-braked commercial vehicles. Thank you for your commitment to improving commercial vehicle brake safety.

From: Indian Head Industries, Inc.
To: NTSB
Date: 3/7/2014
Response: -From R.I. Parker, Chairman and CEO: MGM Brakes, a division of Indian Head Industries (I HI) is in receipt of your letter dated February 10th, 2014 referring to NTSB recommendation H-02-22, and your subsequent inquiry as to the status of IHI's actions to implement this safety recommendation. IHI has long been a commercial vehicle industry safety advocate, and is supportive of initiatives which improve safety on our roads and that of the general public. IHI was the first to invent and patent the "tamper resistant" brake actuator which greatly reduced the potential of injury to mechanics working on commercial air brake equipped vehicles. IHI then licensed this safety technology to IHI competitors in order to make this technology available to the general public. Subsequently, IHI has also invented and patented "electronic brake monitoring" safety technology for commercial air brake equipped vehicles. IHI has successfully deployed this technology in the heavy duty transit bus market, and has attempted to convince the commercial tractor-trailer market of its potential but with little success. IHI has advocated this safety technology at various government agencies, trade associations, and the general commercial vehicle industry for many years. Please see appendix A which lists the development history of this technology for the North American market. In regards to recommendation H-02-22 and I HI's actions to implement this safety recommendation, we have the following comments: Broken power springs are the most typical and prevalent failure mode of a parking brake actuator on commercial air brake equipped vehicles. This is the natural "end-of-life" failure mode for most parking brake actuators, and is caused by life-cycle fatigue of the power parking spring, and potentially by the effects of corrosion as the power parking spring is highly stressed. Most brake actuator manufacturers go to great lengths in designing and testing the power parking spring to achieve maximum operating life as well as to reduce the effects of externally introduced corrosion. There is a product life-cycle limit inherent to all brake actuators, and they are considered a consumable item that should be replaced at regular service intervals as a proactive and precautionary vehicle maintenance practice. Unfortunately the maintenance practices vary greatly from fleet to fleet in terms of proactive replacement of brake actuators as they approach end of life. As NTSB is aware, the power parking spring is located inside the brake actuator and is not conducive to an effective visual inspection. This is because the power spring is a highly stressed component (up to 2000-3000 pounds of force) and it must be enclosed for safety as well as for protection against the effects of corrosion from the external environment. Knowing that power parking spring failure is the prevalent end-of-life failure for most brake actuators, IHI has worked diligently for the past several years on solutions to this problem. • IHI invented electronic brake monitoring in part, to address the issue of broken power springs on commercial vehicles. While electronic brake monitoring technology cannot detect all power spring failure scenarios, it does provide a substantial and significant improvement over the current manual methods of detection. It is I HI's position that if electronic brake monitoring technology was deployed across all commercial vehicles, the detection and replacement of brake actuators with failed power parking springs would be greatly improved and these occurrences greatly reduced. • Electronic brake monitoring can detect the following broken power parking spring scenarios: o When the parking brake is applied by the driver, the brake actuator pushrod should advance as the power parking spring engages. If the power parking spring is broken, the brake actuator pushrod may not properly advance when the parking brake is applied. Electronic brake monitoring technology monitors the brake actuator push rod for proper movement using a sensor inside the brake actuator. This failure can then be subsequently detected by the electronic brake monitoring system and reported to the driver. Note: this failure mode is not 100% detectible as there are many ways a parking power spring can fracture, however this condition would be detectible in many cases. o When the power parking spring fails, it typically breaks into sections. When this occurs the broken sections of the power parking spring typically lacerate the parking diaphragm (in a double diaphragm brake actuator). Once the parking brake actuator diaphragm is compromised, the resulting air leak is to the extent that the vehicle brake system cannot maintain adequate air pressure in the parking brake circuit. As this air leak then develops, the opposite parking brake on the same axle will not be able to remain caged with air. This failure can then result in a brake drag condition which can be readily detected by electronic brake monitoring and reported to the driver. Note: this failure mode exists on double diaphragm parking brakes, but does not exist on piston-diaphragm parking brakes as there is no parking diaphragm in the brake actuator. o When the power parking spring fails, as stated earlier it typically breaks into sections. When this occurs it is possible for the broken sections of the parking spring to prevent proper release (caging) of the parking brake with air. This condition would then result in a partially returned parking brake which can be detected by electronic brake monitoring as a dragging brake condition. In addition, IHI has an active research and development program, and IHI is examining other potential technical solutions to this industry safety problem. While IHI is not in a position to disclose this research at this time, IHI will certainly make NTSB aware of any new emerging technology that is successfully developed to address the concerns raised in NTSB recommendation H-02-22. However, as stated above, IHI does feel that electronic brake monitoring technology does address the issue of detecting broken power springs. IHI is certain that if this technology was widely deployed, that many issues with broken parking power springs would be quickly and accurately identified. If you have any questions regarding this correspondence, please do not hesitate to contact either Thomas Wallace- VP Electronic Braking or Ronald I. Parker- CEO Indian Head Industries.

From: NTSB
To: Indian Head Industries, Inc.
Date: 2/10/2014
Response: We last received a letter regarding this recommendation from IHI in December 2002. At that time, you planned to investigate various methods to make it easier for mechanics and inspectors to determine the condition of the brake spring. You were also developing technology to monitor brake actuator stroke electronically, to determine proper function. On March 17, 2003, Safety Recommendation H-02-22 was classified OPEN--ACCEPTABLE RESPONSE pending completion of the recommended action. We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others. Therefore, please inform us about the status of IHI’s actions to implement Safety Recommendation H-02-22.

From: NTSB
To: Indian Head Industries, Inc.
Date: 3/17/2003
Response: The Safety Board notes that MGM Brake Division of Indian Head Industries has been manufacturing spring brakes and service chambers for over 45 years. We commend MGM Brakes for providing brake training schools and materials throughout North America and for its leadership in safety improvements. Your company's new e-stroke technology presents a promising method for indicating to the driver and mechanic that a brake system is not functioning as intended. Your letter indicates that MGM Brakes will actively and specifically address the Safety Board's recommendation to develop a spring brake that would make it easier for mechanics and inspectors to determine the integrity of the spring. Pending our receipt of information indicating that such a brake has been developed, Safety Recommendation H-02-22 is classified OPEN -- ACCEPTABLE RESPONSE.

From: Indian Head Industries, Inc.
To: NTSB
Date: 12/11/2002
Response: Letter Mail Controlled 12/17/2002 10:24:24 AM MC# 2021028 - From Ronald I. Parker, President of MGM Brakes, CEO of Indian Head Industries: MGM Brakes Division of Indian Head Industries is pleased to respond to the National Transportation Safety Board's "Safety Recommendation H-02-22." The Board's recommendation - "Develop a spring brake that allows inspectors or mechanics to view components safely to determine whether the spring is broken" is of much interest to MGM Brakes. MGM has been manufacturing spring brakes and service chambers for over 45 years and is devoted to product and vehicle safety. MGM is a strong supporter of driver and mechanic training for brakes, brake actuation operation, proper use, maintenance and replacement. Our sales and technical support people provide brake training schools and materials in the field throughout North America. MGM Brakes has also led the industry in many safety improvements in air brake actuators. Some of the more significant improvements related to the NTSB concerns of brake adjustment and brake performance are: § Stroke Alert - Highly visible orange stripe on the push rod that becomes visible when stroke is at the CVSA readjustment limit. MGM introduced this in 1988 and it became required by FMVSS-121 in 1994. § Long Stroke Brake Actuators- MGM introduced a full line of longstroke brake actuators at the request of a 1991 FMCSA recommendation for more reserve stroke and performance to compensate for drum expansion on long downgrades. § e-Stroke - MGM introduced a stroke monitoring system that electronically monitors and warns when the stroke is at the readjustment limit or if there is a dragging brake as well as a non-functioning actuator. The e-Stroke product line was released for production two years ago after years of testing and development. MGM will actively address NTSB's recommendation to develop spring brakes that would make it easier for the mechanics and inspectors to determine the integrity of the parking spring. MGM will start with your suggestion for inspection windows and/or ports. Our investigation will have to focus on the practicality of the windows (ports) helping the inspectors in actual vehicle installations. One concern is that we anticipate some installations to be fairly difficult for visual inspection while mounted on the vehicle. Our other main concern is to ensure that they are weather-tight to prevent contaminates from entering the actuator that would potentially shorten the life of the parking spring and could reduce the visibility through the inspection windows. Please note that MGM Brakes has developed a technology that we believe will help to address both the issue of an improperly functioning brake actuator, along with a foundation brake system that is not functioning as designed. MGM Brakes strongly believes our technology to electronically monitor the stroke of a brake actuator is a considerable step forward in the area of brake inspection. This new technology makes it much easier for a driver or maintenance person to perform a pre-trip inspection as mandated in the Federal Motor Carrier Safety Administration Regulation 392.7 - Equipment, Inspection and Use. While this technology does not specifically address the issue of a broken power spring, it will indicate if the broken power spring is causing the actuator to function improperly. In addition, it also serves to alert the driver or maintenance person that the foundation brake system needs to be adjusted or repaired when the electronic diagnostic system has indicated the brake system is not functioning as designed. We believe MGM Brake's e-Stroke technology would have detected the root cause of the accident and thus have prevented the accident. Brake actuator stroke sensing was part of Robert Kreeb's of Booz Allen Hamilton and Deborah Freund's of Federal Motor Carrier Safety Administration presentation at the SAE (Society of Automotive Engineers) Truck and Bus fall 2002 meeting. Their presentation was entitled "Advance Brake Sensor Technologies for Commercial Vehicles. As part of their conclusion they stated, "Brake chamber stroke monitoring systems are affective in determining out-of-adjustment and dragging brakes". Enclosed is literature on MGM's long stroke brake and e-Stroke system for your reference.

From: NTSB
To: Carlisle Motion Control Industries, Inc.
Date: 12/30/2002
Response: Carlisle indicates that it has developed a spring brake that allows inspectors and mechanics to view components safely to determine whether a spring brake is functioning properly. While the system will not allow inspectors and mechanics to directly view components that determine whether the spring is broken, it does allow them to determine whether functions critical to spring brake operation are occurring as they should. The Safety Board recognizes that the ability of the actuator to return to zero stroke is critical to the proper operation of Carlisle spring brakes. Carlisle indicates that its spring brakes use a stroke-indicating sticker that not only shows the point of readjust (colored in red), but also the proper operating range of stroke (colored in green). This feature helps inspectors ensure that the chamber has returned to zero stroke by verifying that the green zone of the sticker has not protruded out of the housing. If it has, service on the spring brake is required. The Safety Board notes Carlisle's position that using the sticker is superior to other identification marks because it acts as a gauge to indicate the exact position of stroke of the chamber. Because Carlisle developed a brake that allows an inspector or mechanic to determine whether functions critical to spring brakes are occurring as they should before the Board's recommendation was issued, Safety Recommendation H-02-22 is classified CLOSED -- RECONSIDERED.

From: Carlisle Motion Control Industries, Inc.
To: NTSB
Date: 10/3/2002
Response: Letter Mail Controlled 10/08/2002 3:46:34 PM MC# 2020855: - From Tom Hogan, President: Attached you will find a detailed report from our product engineering manager concerning NTSB's safety recommendation, H-02-22, for spring brake actuators. This unfortunate accident may have been avoided if the truck was outfitted with Carlisle's spring brake actuators, which already have an inspection method as a standard feature. Although this inspection method may not point to the specific cause of failure of the actuator, it will alert a mechanic or operator that the brakes will not operate properly. Corrective action can then be taken well before an unsafe situation is encountered. Our opinion is that no further action is required by Carlisle to assure that a similar accident is avoided.

From: NTSB
To: Haldex Commercial Vehicle Systems, Inc.
Date: 2/10/2014
Response: We have not yet received a response from Haldex regarding actions to address these recommendations. Accordingly, Safety Recommendations H-02-22 and H-06-8 have been classified OPEN—AWAIT RESPONSE since their issuance. We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others. Therefore, please inform us about the status of Haldex’s actions to implement Safety Recommendations H-02-22 and H-06-8.