[Federal Register Volume 61, Number 186 (Tuesday, September 24, 1996)]
[Proposed Rules]
[Pages 49992-49998]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-24206]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Parts 571 and 572

[Docket No. 96-098, Notice 01]
RIN 2127-AG37


Side Impact Protection Side Impact Dummy

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

ACTION: Notice of proposed rulemaking.

-----------------------------------------------------------------------

SUMMARY: This document proposes two amendments to the specifications 
for the side impact test dummy and to the procedure in NHTSA's side 
impact protection standard for positioning the dummy in a vehicle for 
compliance testing purposes. The first amendment would add plastic 
inserts-spacers to the dummy's lumbar spine. This change is intended to 
prevent a cable within the spine from snapping, which some 
manufacturers believe can generate large spikes in the data obtained 
from the dummy. The second amendment would specify that the ribcage 
damper piston of the dummy is set during the dummy positioning 
procedure to the fully extended position prior to the side impact 
dynamic test. These changes are intended to improve the consistency of 
the data obtained from the dummy in a side impact crash test.

DATES: Comments on this proposed rule must be received by the agency no 
later than November 25, 1996.
    Proposed effective date: 45 days after publication of a final rule 
in the Federal Register.

ADDRESSES: Comments should refer to the docket number and notice number 
and be submitted in writing to: Docket Section, National Highway 
Traffic Safety Administration, Room 5109, 400 Seventh Street, S.W., 
Washington, D.C., 20590. Telephone: (202) 366-5267. Docket hours are 
9:30 a.m. to 4:00 p.m. Monday through Friday.

FOR FURTHER INFORMATION CONTACT: For nonlegal issues: Mr. Stan 
Backaitis, Office of Vehicle Safety Standards, (telephone 202-366-
4912). For legal issues: Ms. Deirdre Fujita, Office of the Chief 
Counsel (202-366-2992). Both can be reached at the National Highway

[[Page 49993]]

Traffic Safety Administration, 400 Seventh St., S.W., Washington, D.C., 
20590.

SUPPLEMENTARY INFORMATION:

Background

    On October 30, 1990, NHTSA published a rule that established 
dynamic side impact protection requirements for passenger cars. (See, 
final rule amending Federal Motor Vehicle Safety Standard No. 214, Side 
Impact Protection, 49 CFR 571.214; 55 FR 45722.) The requirements, 
which became effective September 1, 1993, improve safety by providing 
protection against injuries to an occupant's thorax and pelvis in a 
side impact crash.
    The requirements provide this protection by placing a side impact 
dummy (SID) in a vehicle, subjecting the vehicle to a side impact crash 
test and limiting the amounts of force measured by accelerometer 
sensors mounted in the thorax and pelvis of the SID. The SID represents 
an adult male 50th percentile size occupant. At the time of the 
amendment to Standard 214, specifications for the SID were added to 
NHTSA's test dummy regulation (see, 49 CFR part 572, subpart F).
    Four accelerometers are used to measure the crash test forces. 
Three accelerometers are mounted in the dummy's thorax and provide 
acceleration values used in determining the ``Thoracic Trauma Index 
(TTI(d)).'' TTI(d) is an injury criterion that measures the risk of 
thoracic injury of a passenger car occupant in a side impact. The 
fourth accelerometer, mounted in the pelvic cavity, measures the 
potential risk for pelvic injury. To meet Standard 214's side impact 
protection requirements, the TTI(d) and pelvic measurements must be 
below specified maximum values.

Lumbar Spine Inserts

    The lumbar spine of the SID is a molded hollow cylindrical rubber 
element, with bonded circular metal plates that have a hole in the 
center at each end. A metal cable passes through the center of the 
lumbar spine cylinder. The top end of the cable is threaded, and the 
bottom end is shaped like a ball. The threaded end of the cable is 
fastened with a nut, which can be tightened to provide the desired 
compression in the lumbar.
    A number of motor vehicle manufacturers have informed NHTSA that 
they have observed spikes in data obtained from side impact tests that 
increase the variability and the magnitude of the TTI(d). The American 
Automobile Manufacturers Association (AAMA), representing Ford, 
Chrysler Corporation and General Motors Corporation, raised the issue 
of these spikes in a June 29, 1994 letter to the agency. AAMA said that 
metal-to-metal contact in the SID lumbar spine--

is inducing data spikes that are of long enough time duration to 
become part of the data when it is filtered according to the 
requirements of Standard No. 214. Inclusion of these data spikes in 
the data increases variability and unwarrranted higher calculations 
of TTI(d). The spikes could cause manufacturers to redesign their 
vehicles for no safety reason other than an artifact of the SID. 
This redesign would increase business costs with no safety benefit 
to the customer.

    AAMA stated that it determined that the noise spikes were caused by 
(1) the nut and threaded area on top of the metal spine cable striking 
the inner edge of the hole of the metal top-plate of the lumbar spine 
when the spine flexes; (2) the ball at the end of the lumbar spine 
cable popping in and out of the seat of the metal bottom plate when the 
spine is compressed; and (3) the spine cable nut hitting the thorax to 
lumbar spine adaptor assembly.
    Toyota Motor Corporate Services of North America (Toyota) also 
informed NHTSA that it was concerned about ``unwarranted spine * * * 
noise.'' (Letter to NHTSA from Mr. Saburo Inui, October 21, 1994.) 
Toyota confirmed that the ``noise'' that AAMA found in the data traces 
also occurred during Toyota's compliance and experimental development 
tests. The manufacturer requested NHTSA to modify the SID 
specifications by covering the spine cable with a shrinking plastic 
tube and placing a rubber washer between the top-plate and the 
fastening nut.
    Subsequently, AAMA recommended specific corrections to the SID to 
eliminate the spine ringing. In a December 13, 1994 letter (see item 
88-07-N03-006 in NHTSA's docket), AAMA recommended adding Delrin 
spacers in the top and bottom plates of the lumbar spine:

    These spacers would be an efficient and effective way to correct 
the spine ringing problem in the SID. They would be inserted into 
the top and bottom plate of the lumbar spine assembly. No 
modifications to the lumbar spine would be required for their use. 
This would be cost effective for dummy users, since their inventory 
of SID lumbar spines, would not have to be returned to dummy 
manufacturers for rework. * * *

    AAMA stated that Ford conducted component testing to determine the 
effect of using the Delrin inserts on SID performance. Ford found that 
when the Delrin spacers were used, the data spikes were eliminated. 
AAMA also said that in subsequent crash tests conducted by member 
companies, no indications of spine ringing were found when the spacers 
were used. AAMA provided data to substantiate that relevant SID 
responses would not be altered by the use of the spacers, i.e., they do 
not alter the SID responses except for the elimination of spine noise. 
AAMA also indicated that the spacers are durable and are readily 
available from Vector Research, a dummy manufacturer.
    On March 29, 1995, Mercedes Benz submitted a letter to NHTSA 
supporting the use of the Delrin spacers, as suggested by AAMA. The 
manufacturer stated: ``After much testing, we believe the AAMA has 
provided sufficient evidence that artificial `noise' is eliminated by 
using these spacers and that the relevant SID responses are not 
affected.''
    After receiving these letters and comments, NHTSA reviewed data it 
obtained from tests with the SID for evidence of spine noise (spikes). 
None of the available agency experimental or vehicle compliance data 
indicated definitive evidence of data contamination and/or distortion 
clearly attributable to spine cable snap. Further, it appeared from 
data submitted by Ford that the ``noise'' that the manufacturer found, 
while visible primarily in several portions of the raw data traces, 
would nonetheless be reduced to insignificant values by the specified 
FIR filter. Also, the noise consisted of extremely short duration 
spikes occurring earlier or considerably later than the peak 
acceleration magnitudes in real world crash tests. Usually such short 
duration spikes do not have much energy content and accordingly, have 
little or no effect on the true acceleration measurement, particularly 
since they do not occur at points in time at which the TTIs are at 
maximum.
    While the agency's data did not show that spine noise was 
problematic, NHTSA conducted further investigations to better 
understand the manufacturers' concerns. In January 1995, NHTSA 
determined through component tests of the SID torso that manufacturers 
were correct that slippage of the SID's spine cable anchorage can 
produce spikes in the data. (A July 1996 memorandum describing the 
testing is in Docket 88-07, Notice 3.) In the component tests, the SID 
upper torso part was rocked while the bottom half was held rigid. The 
rocking tests caused the cable ends to slip, resulting in the 
generation of low level ``clicking'' and some minor noise spikes in the 
ribcage response data. It should be noted, however, that

[[Page 49994]]

none of the rocking motions producing spine cable snap generated spikes 
that had any resemblance in shape or in magnitude to those described by 
AAMA or Toyota.
    NHTSA also found in the rocking tests that the Delrin spacers, 
which AAMA suggested the agency should use in the SID spine, stopped 
the cable from slipping and eliminated the clicking noise. In a series 
of sled tests, NHTSA also determined that the spine inserts produce 
somewhat less spikelike acceleration responses in the raw unfiltered 
data compared to tests without the spacers. In a series of impact 
tests, the agency established that the spacers had no appreciable 
effects on stiffness of the spine, but resulted in lower magnitudes of 
spikes in the ``z'' (vertical) acceleration channel. NHTSA also found 
that the inserts have little, if any, effect on the TTI value 
measurements. The above tests are described in a July 1996 memorandum 
in Docket 88-07, Notice 3.
    While the agency's data do not support the claims of some 
manufacturers that spine noise affects the TTI(d) measurements 
sufficiently to compel the possible redesign of their vehicles, NHTSA 
has confirmed that the SID spine cable does move in a ``snap-like'' 
motion that can produce low level spikes that are clearly visible in 
unfiltered raw data. This ``noise,'' while thus far negligible upon FIR 
filtering, is nonetheless undesirable in itself as part of the crash 
event. Any looseness or snapping of components within the SID can 
produce rattling or unwarranted snapping effects that could potentially 
distort the data from the dummy and possibly complicate compliance 
testing. NHTSA therefore tentatively concludes that ``noise'' from 
movement of the spine cable should be minimized to the extent 
reasonably possible and that spacers inserted into appropriate places 
in the spine are a reasonable means of effectively preventing such 
movement. Accordingly, the agency proposes to amend the specifications 
for the SID to incorporate use of lumbar spine spacers in Standard 214 
compliance tests. Estimated cost of the two spacers is $154. Given that 
on average, a SID can be used in at least 30 tests, the estimated cost 
of the spacers is at most $5 per impact test.
    Readers are invited to provide test data and comments relating to 
their experience in testing dummies equipped with lumbar spine spacers.

Proposed Drawing Revisions

    To incorporate the use of lumbar spine spacers, this proposal would 
replace dummy assembly drawing SA-SID-M050, revision A (dated May 18, 
1994) with revision B. Revision B would include reference to:
    1. Drawing Lumbar Spacers-Lower SID-SM-001, which indicates the 
spine lower spacer;
    2. Drawing Lumbar Spacers-Upper SID-SM-002, which indicates the 
spine upper spacer; and
    3. Drawing 78051-243 to indicate a washer.
    The drawings for the SID spine lower spacer and upper spacer are 
depicted in this NPRM in figures 1 and 2, respectively.

BILLING CODE 4910-59-P

[[Page 49995]]

[GRAPHIC] [TIFF OMITTED] TP24SE96.084



[[Page 49996]]

[GRAPHIC] [TIFF OMITTED] TP24SE96.085


BILLING CODE 4910-59-C

[[Page 49997]]

    The SID users manual, dated May 1994, would be revised to reflect 
the assembly of the above parts.

Damper Piston Movement

    During the sled tests that the agency conducted to evaluate the 
effect of spacer inserts in the SID lumbar spine, NHTSA observed that 
the position of the damper piston in the SID ribcage prior to the test 
had an appreciable effect on the thorax accelerations recorded by the 
SID. In some tests, some of the thorax responses contained initial 
short duration damper piston movement in the direction opposite of 
impact, followed by a longer duration movement in the direction of 
impact. Upon closer inspection of the damper piston position in dummies 
set up for impact, NHTSA noted that the damper position was not fully 
extended in some of the dummies. The agency subsequently found, through 
tests with the damper piston position purposely fully extended or 
partly compressed, that the damper piston's initial position can be an 
important factor in determining whether the dummy's key thorax sensors 
will record higher or lower accelerations.
    In a side impact in which contact occurs first at the dummy's hip 
level, a dummy's ribcage initially moves (relative to the pelvis bone) 
toward the impact. When the damper piston is partly compressed prior to 
impact, the damper piston will fully extend itself during impact until 
it is arrested by the piston bottoming out against the damper body. The 
test data indicate that this internal ``collision'' of the damper 
piston against the damper body is the primary cause of inconsistency in 
data measurements and the determination of acceleration levels. This 
collision does not occur when the piston is fully extended within the 
damper body prior to the test.
    To better ensure that the impact response measurements are more 
repeatable and reproducible, NHTSA proposes to specify in Standard 
214's SID positioning procedures that the damper piston is in the fully 
extended position before the test. Prior to sled tests that showed the 
apparent damper piston position problem, the agency believed that a 
piston return spring in the SID would develop sufficient force to set 
the damper piston in the fully extended position. It appears, however, 
that the spring is not stiff enough to set the piston in every dummy in 
the fully extended position and that steps to ensure extension of the 
piston are necessary.
    NHTSA found that the piston can be fully extended by rocking a 
seated dummy in the lateral direction immediately prior to a test or by 
reaching through a partly unzipped SID torso jacket and forcing the 
piston into a full extension. NHTSA believes these measures will ensure 
that the damper piston is in the fully extended position at the time of 
the side impact test. NHTSA tentatively concludes that a visual 
inspection appears to be adequate to ensure that the piston is fully 
extended and that a position sensor may not be needed. However, it is 
noted that for users who want assurance, through measurements, that the 
piston position is fully extended, the SID specifications package 
already allows use of a ribcage position sensor as an option. The cost 
of the sensor, with mounting brackets, is approximately $1,025. 
Comments are requested on whether the SID specifications package should 
require the use of a sensor.

Rulemaking Analyses and Notices

Executive Order 12866 and DOT Regulatory Policies and Procedures

    NHTSA has considered the impact of this rulemaking action under 
E.O. 12866 and the Department of Transportation's regulatory policies 
and procedures. This rulemaking document was not reviewed under E.O. 
12866, ``Regulatory Planning and Review.'' This action has been 
determined to be ``non-significant'' under the Department of 
Transportation's regulatory policies and procedures. The proposed 
amendments would not require any vehicle design changes but would 
instead only require minor modifications in the test dummy used to 
evaluate a vehicle's compliance with Standard No. 214. According to 
Vector Research, a dummy manufacturer, the two Delrin spacers (lumbar 
spine inserts) cost $154. Thus far, these have been precision machined 
parts aimed to satisfy individual low volume orders. The cost is 
expected to decrease considerably once the other dummy manufacturer 
(FTSS) begins manufacturing the spacers. If use of spacers increases, 
dummy manufacturers may seek to produce them through precision molding, 
which could further reduce the cost of the spacer. The agency has 
determined that the impacts of the proposed amendments would be so 
minimal that a full regulatory evaluation is not required.

Regulatory Flexibility Act

    NHTSA has also considered the impacts of this notice under the 
Regulatory Flexibility Act. I hereby certify that this proposed rule 
would not have a significant economic impact on a substantial number of 
small entities. Modifications to dummy designs affect motor vehicle 
manufacturers, few of which are small entities. As described above, 
there would be no significant economic impact on any vehicle 
manufacturers, whether large or small. Further, since no price 
increases would be associated with the proposed rule, small 
organizations and small governmental units would not be affected in 
their capacity as purchasers of new vehicles.

National Environmental Policy Act

    NHTSA has also analyzed this proposed rule under the National 
Environmental Policy Act and determined that it would not have a 
significant impact on the human environment.

Executive Order 12612 (Federalism)

    NHTSA has analyzed this proposal in accordance with the principles 
and criteria contained in E.O. 12612, and has determined that this 
proposed rule would not have significant federalism implications to 
warrant the preparation of a Federalism Assessment.

Civil Justice Reform

    This proposed rule would not have any retroactive effect. Under 49 
U.S.C. 30103, whenever a Federal motor vehicle safety standard is in 
effect, a State may not adopt or maintain a safety standard applicable 
to the same aspect of performance which is not identical to the Federal 
standard, except to the extent that the state requirement imposes a 
higher level of performance and applies only to vehicles procured for 
the State's use. 49 U.S.C. 30161 sets forth a procedure for judicial 
review of final rules establishing, amending or revoking Federal motor 
vehicle safety standards. That section does not require submission of a 
petition for reconsideration or other administrative proceedings before 
parties may file suit in court.

Submission of Comments

    Interested persons are invited to submit comments on the proposal. 
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

[[Page 49998]]

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 proposal 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. Comments received too 
late for consideration in regard to the final rule will be considered 
as suggestions for further rulemaking action. Comments on the proposal 
will be available for inspection in the docket. 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.

List of Subjects

49 CFR Part 571

    Imports, Motor vehicle safety, Motor vehicles.

49 CFR Part 572

    Motor vehicle safety, Incorporation by reference.

    In consideration of the foregoing, NHTSA amends 49 CFR Parts 571 
and 572 as set forth below.

PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS

    1. The authority citation for Part 571 would continue to read as 
follows:

    Authority: 49 U.S.C. 322, 30111, 30115, 30117 and 30166; 
delegation of authority at 49 CFR 1.50.


Sec. 571.214  [Amended]

    2. Section 571.214 would be amended by adding an introductory text 
for S7.1, Torso, to read as follows:
    S7.1  Torso. For a test dummy in any seating position, the piston 
of the torso damper (SID 083) is fully extended.
* * * * *

PART 572--ANTHROPOMORPHIC TEST DUMMIES

    3. The authority citation for Part 572 would continue to read as 
follows:

    Authority: 49 U.S.C. 322, 30111, 30115, 30117 and 30166; 
delegation of authority at 49 CFR 1.50.

    4. In section 572.41, the introductory text of (a), and paragraphs 
(a)(4) and (c) would be revised to read as follows:


Sec. 572.41  General description.

    (a) The dummy consists of component parts and component assemblies 
(SA-SID-M001A, revision B, dated [to be determined] which are described 
in approximately 250 drawings and specifications that are set forth in 
Sec. 572.5(a) with the following changes and additions which are 
described in approximately 85 drawings and specifications (incorporated 
by reference; see Sec. 572.40):
* * * * *
    (4) The lumbar spine consists of the assembly specified in subpart 
B (Sec. 572.9(a)) and conforms to drawing SA 150 M050 and drawings 
subtended by SA-SID-M050 revision B, dated [to be determined], 
including the addition of Lumbar Spacers-Lower SID-SM-001 and Lumbar 
Spacers-Upper SID-SM-002, and Washer 78051-243.
* * * * *
    (c) Disassembly, inspection, and assembly procedures; external 
dimensions and weight; and a dummy drawing list are set forth in the 
Side Impact Dummy (SID) User's Manual, dated [to be determined] 
(incorporated by reference; see Sec. 572.40).
* * * * *
    5. In section 572.43, paragraph (a) would be revised to read as 
follows:


Sec. 572.43  Lumbar spine and pelvis.

    (a) When the pelvis of a fully assembled dummy (SA-SID-M001A 
revision B, dated [to be determined] (incorporated by reference; see 
Sec. 572.40) is impacted laterally by a test probe conforming to 
Sec. 572.44(a) at 14 fps in accordance with paragraph (b) of this 
section, the peak acceleration at the location of the accelerometer 
mounted in the pelvis cavity in accordance with Sec. 572.44(c) shall be 
not less than 40g and not more than 60g. The acceleration-time curve 
for the test shall be unimodal and shall lie at or above the +20g level 
for an interval not less than 3 milliseconds and not more than 7 
milliseconds.
* * * * *
    Issued on September 16, 1996.
L. Robert Shelton,
Acting Associate Administrator for Safety Performance Standards.
[FR Doc. 96-24206 Filed 9-23-96; 8:45 am]
BILLING CODE 4910-59-P