[Federal Register Volume 60, Number 141 (Monday, July 24, 1995)]
[Proposed Rules]
[Pages 37864-37866]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-18107]



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DEPARTMENT OF TRANSPORTATION
49 CFR Part 571

[Docket No. 95-57; Notice 01]
RIN 2127-AF72


Air Brake Systems

AGENCY: National Highway Traffic Safety Administration (NHTSA), DOT.

ACTION: Request for comments.

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SUMMARY: This notice requests comments about devices that remove water 
and other contaminants from air brake systems. These devices include 
automatic drain valves and air dryers. If it appears from the agency's 
analysis of the comments that such devices are a cost-effective method 
of improving heavy vehicle safety, the agency would issue a notice 
proposing to amend Standard No. 121, Air brake systems, to require such 
equipment.

DATES: Comments must be received by September 7, 1995.


[[Page 37865]]

ADDRESSES: Comments should refer to the docket and notice numbers set 
forth above and be submitted to the Docket Section, NHTSA, Room 5109, 
400 Seventh Street, SW, Washington, DC 20590 (Docket hours are from 
9:30 a.m. to 4 p.m., Monday through Friday).

FOR FURTHER INFORMATION CONTACT: Mr. Richard Carter, Office of Vehicle 
Safety Standards, National Highway Traffic Safety Administration, 400 
Seventh Street, SW, Washington, DC 20590, (202) 366-5274.

SUPPLEMENTARY INFORMATION: Federal Motor Vehicle Safety Standard No. 
121, Air Brake Systems, establishes braking performance requirements 
for vehicles equipped with air brake systems. The standard also 
requires these vehicles to be equipped with certain braking equipment, 
including a ``condensate drain valve that can be manually operated.'' 
(see S5.1.2.4 for trucks and buses and S5.2.1.3 for trailers). The 
condensate drain valve allows contaminants, such as water, oil, and 
dirt to be drained from the brake system's reservoirs. The requirement 
for air reservoirs to be equipped with a drain valve that can be 
manually operated became effective in 1971 and has remained unchanged. 
(36 FR 3817; February 27, 1971)
    On July 28, 1994, Domenic F. Coletta, M.D., the Deputy Medical 
Examiner of Salem County, New Jersey, submitted a petition for 
rulemaking requesting that Standard No. 121 be amended to require 
condensate drain valves that automatically purge the contaminants from 
the air supply reservoir. He stated that currently available automatic 
drain valves would better ensure safety since reservoirs equipped with 
manual drain valves are not usually drained on a regular basis. As a 
result, he contends that contaminants are present in reservoirs, a 
situation which leads to the unsafe operation of trucks and buses. The 
petitioner referenced conversations with truck drivers and New Jersey 
State police to support his contention that manual drain valves are 
typically not being used to remove contaminants from the reservoirs. 
However, he supplied no data about the extent to which requiring 
automatic drain valves would enhance motor vehicle safety.
    On February 21, 1995, NHTSA granted Dr. Colleta's petition to 
consider amending Standard No. 121 to require automatic drain valves. 
The agency has determined that it is desirable to issue today's notice 
requesting comments about automatic drain valves and the effects of 
contaminants in air brake systems before proceeding further with a 
rulemaking to amend the standard.
    Manufacturers of heavy vehicles and heavy vehicle users believe 
that it is important to ensure that an air brake system is clean and 
dry. If water is present, valves in the air brake systems may freeze, 
which may cause the brakes to fail. More generally, contaminants may 
enter relay valves, causing their intake and exhaust seals not to seal 
properly. This will result in air leakage and in turn degrade brake 
performance. This is particularly likely to be a problem for valves 
used with antilock systems since they have smaller orifice sizes and 
therefore are more sensitive to contaminants. Notwithstanding these 
potential safety problems, the predominant effect of contaminants in an 
air brake system appears to be shortened component life rather than a 
significant causal factor in heavy vehicle accidents. The Truck 
Maintenance Council of the American Trucking Associations has been 
working with the vehicle manufacturers to achieve longer component life 
for the fleet owners.
    To keep air brake systems, particularly the air reservoirs, dry and 
free from contaminants, manufacturers have installed certain equipment 
in the air brake systems. These include drain valves and air dryer 
systems. Maintenance personnel and truck drivers are encouraged to keep 
air brake systems dry and clean, by opening the reservoir drain valve 
and inspecting the brake hoses.
    There are two types of drain valves: Manual and automatic. Both 
types of valves serve to purge the reservoir of water and other 
contaminants. With a manual drain valve, it is necessary for the truck 
driver or maintenance person to open the valve and drain the reservoir. 
While ideally this should be done each morning before the vehicle is 
started, some drivers do not do so. With an automatic drain valve, the 
reservoir is drained without the need for human intervention.
    Air dryers also serve to reduce the amount of water and other 
contaminants in an air brake system by cleaning and drying the air. 
There are two types of air dryers, desiccant style systems and ``after-
cooler'' systems. In a typical desiccant style system, the incoming air 
is routed into the air dryer at the bottom end of the unit, which 
contains an area called a sump. The rapid swirling of the incoming air 
into the sump causes a large portion of the oil and water mist to fall 
to the bottom of the sump. This partially cleaned air then goes through 
an oil separator which is placed directly above the sump area. Next the 
air, which is still moist with both oil and water vapor, is passed 
through a ``drying bed'' of desiccant material that removes the 
remaining moisture. These dryers are equipped with an automatic drain 
valve that periodically purges water and contaminants from the air 
system and are mounted directly after the compressor. In contrast, in a 
typical ``after-cooler'' system, which uses an air cleaner only, not 
all the moisture is removed, since the air is not passed through a 
drying bed of desiccant material. Each type of dryer may be equipped 
with built-in heaters to prevent the purge valves from freezing in cold 
weather. The heaters are standard equipment on some models and optional 
on others.
    In its October 1993 fleet study on antilock brake systems, NHTSA 
concluded that while fleets equipped with after-cooler style air dryers 
experienced leaky valves, other fleets equipped with desiccant style 
air dryers ``have not experienced leaking relay valves.'' \1\ Over 80 
percent of new air braked heavy trucks are being built with air dryers, 
according to AlliedSignal. That brake manufacturer estimates that more 
than 90 percent of the dryers are the desiccant type. Moreover, that 
company predicted that in five years almost all air braked vehicles 
will be equipped with an air cleaning and drying system.

    \1\ An ``In-Service Evaluation of the Performance, Reliability, 
Maintainability, and Durability of Antilock Braking Systems (ABSs) 
for Semitrailers'' (DOT HS 808 059, Final Report, October 1993)
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    To assist NHTSA in determining whether to initiate a rulemaking to 
require equipping air braked vehicles with automatic drain valves or 
desiccant type air dryers, the agency seeks responses to the following 
questions:
    1. Do contaminants in air brake systems cause a significant safety 
problem? Are any data available to support the existence of such a 
problem? How many vehicle crashes per year can be attributed to being 
caused by air contaminants of the type that would be eliminated by the 
mandatory installation of automatic drain valves? How many deaths and 
injuries, and how much property damage, result from these crashes?
    2. What is the experience of manufacturers, vehicle operators, and 
maintenance personnel with automatic drain valves and desiccant type 
air dryers? How effective is each device in removing water and other 
contaminants from an air brake system? Are both automatic drain valves 
and desiccant type air dryers being installed on the same air braked 
vehicle?
    3. Is it necessary or appropriate to require air braked vehicles to 
be 

[[Page 37866]]
equipped with both desiccant style air dryers and automatic drain 
valves as well?
    4. Based on its preliminary analysis, NHTSA estimates that the cost 
to the customer at retail for automatic drain valves ranges from $75 to 
$400 per reservoir depending upon the type of system . AlliedSignal 
manufactures an automatic drain valve costing approximately $75 per 
unit, installed at retail, while the $400 unit would include a 
desiccant type system with a heater. Stop Enterprises, the company 
referenced by the petitioner, manufactures an automatic drain valve 
costing approximately $100 per unit. This compares to approximately $15 
for a manual drain valve installed at retail. The agency requests 
comments about whether these estimated costs for automatic and manual 
drain valves are accurate.
    5. The cost to the vehicle manufacturer of desiccant style air 
dryers is estimated to be $160 per unit (exclusive of installation). 
The agency requests comments about the costs associated with this 
device.

Rulemaking Analyses

    This notice was not reviewed under E.O. 12866. NHTSA has analyzed 
this notice and determined that it is not ``significant'' within the 
meaning of the Department of Transportation's regulatory policies and 
procedures. While a full regulatory evaluation is not required because 
the notice merely requests comments on a potential rule, the agency 
estimates that such a requirement would have the following effect.
    Approximately 397,500 vehicles are manufactured each year that are 
subject to Standard No. 121. Of these, approximately, 189,000 are 
trailers. According to estimates by the agency and the Truck Trailer 
Manufacturers Association (TTMA), manual drain valves are installed on 
approximately 99 percent of the units. The other one percent have 
automatic drain valves. Of the annual production of air braked 
vehicles, approximately 60,900 vehicles are comprised of single unit 
trucks (including school bus chassis), and transit and intercity buses. 
The agency estimates that 75 percent are equipped with automatic drain 
valves. The remaining 25 percent have manual drain valves. The balance 
of the production in air braked vehicles are truck tractors averaging 
approximately 147,600 vehicles annually. These vehicles have the 
highest installation rates of automatic drain valves and are presently 
estimated to be installed on approximately 85 percent of the vehicles 
built new. Industry sources estimate the remaining 15 percent of the 
truck tractors not built with automatic purge valves will be so 
equipped in the next five years. It is expected that the installation 
rate will be in conjunction with the phasing in of antilock brake 
systems on heavy vehicles.
    NHTSA estimates that the installed cost at retail of adding 
automatic drain valves to trailers would range from $75 to $150 
depending upon the number of air reservoirs. Considering that 
approximately 99 percent of the trailers built new would require the 
addition of these units, the estimated cost would range from $15.5 
million on single reservoir trailers with no heater to $31 million for 
single reservoir trailers with heated valves. On double reservoir 
trailers, the costs would be double, if automatic drain valves are 
installed on both air tanks. On straight trucks, bus chassis, and other 
buses, the additional 25 percent (approximately 15,225 units) which 
would require automatic drain valves would represent an additional cost 
ranging from $1.2 to $6.1 million depending upon the choice of system 
(i.e., ranging from a very basic automatic system with no heater or 
dryer to a full desiccant style system with heater). Approximately 85 
percent of truck tractors are equipped with automatic drain valves 
including air dryers and thus would require an expenditure ranging from 
$1.7 million to $8.8 million, depending on the type of system selected.
    Based on the above analysis, NHTSA estimates that the total 
incremental cost at retail level, resulting from requiring automatic 
drain valves ranges from $18.4 to $76.9 million, depending upon the 
system being selected.

Public Comments

    Interested persons are invited to submit comments on the notice. It 
is requested but not required that 10 copies be submitted.
    All comments must not exceed 15 pages in length. (49 CFR 553.21). 
Necessary attachments may be appended to these submissions without 
regard to the 15-page limit. This limitation is intended to encourage 
commenters to detail their primary arguments in a concise fashion.
    If a commenter wishes to submit certain information under a claim 
of confidentiality, three copies of the complete submission, including 
purportedly confidential business information, should be submitted to 
the Chief Counsel, NHTSA, at the street address given above, and seven 
copies from which the purportedly confidential information has been 
deleted should be submitted to the Docket Section. A request for 
confidentiality should be accompanied by a cover letter setting forth 
the information specified in the agency's confidential business 
information regulation. 49 CFR Part 512.
    All comments received before the close of business on the comment 
closing date indicated above for the notice will be considered, and 
will be available for examination in the docket at the above address 
both before and after that date. To the extent possible, comments filed 
after the closing date will also be considered. The NHTSA will continue 
to file relevant information as it becomes available in the docket 
after the closing date, and it is recommended that interested persons 
continue to examine the docket for new material.
    Those persons desiring to be notified upon receipt of their 
comments in the rules docket should enclose a self-addressed, stamped 
postcard in the envelope with their comments. Upon receiving the 
comments, the docket supervisor will return the postcard by mail.

    Issued on: July 18, 1995.
Barry Felrice,
Associate Administrator for Safety Performance Standards.
[FR Doc. 95-18107 Filed 7-21-95; 8:45 am]
BILLING CODE 4910-59-P