Document rpqbNnp667y2Lj37k2ErKdYmV
FILE NAME Manville JMA
DATE 1971 DOC JMA124
DOCUMENT DESCRIPTION Cobra Railroad Brake Tests by M Westinghouse
MANVILLE RESTARCH
Contral Memorandum Contral Contral
Contral Contral
Contral
101 1101 101
1101
,, ,, 18/30
COPRA PART A Sto. TON NVESTIGATION NVESTIGATION
TRIP TO WW tha je BPARE DEVESTON DEVESTON
JULY
26-30
1971
troduction
a
eg:
Recently Posea h
onsdruple onsdruple West e
correspondence has been Air Brake Division the
exchanged between ManvillMane ville
Association of American
roads and the Lavronmental Protection Agency on the subject of possible
haza dous emis som. from COBRA composition railway brake shoes during use
Although coser ot, pregoner pregoner * of interest to the AAR and the FPA ike
10 0050 01 svete lo Just Into The atmosphere is of prime concern at the present
mo
no de ty eos urselvesurselves the AAR and the EPA with information on this
subject a test
wear under
Tom
oa
us
was set up and carried out to sumulated service conditions
collect samples of COBRA This report describes
however
no deta
the le procedures procedures and conditions
It does nol
cover the
Hysis Of The
SumpieSumspies have been
ump es obtained
This
myzed for asbestos
will be reported separately after the and other potentially hazardous material
PERSONNELPERSONEL PRESENT
ini
#ABD
1 to. Adelmann Adelmann
i
F. C. W. F. T. A.
Grejda Grejda
Kahr Kosikowski Kosikowski Filar
Apparatus
The West righouse
used to SERTI
Ave
Marjous
Brake Division Railroad dynamonicter in Wilmerding Pa was
Marjous service conditions for these lests
In order to collect
We dyst oampte , the wheel and braking assembly of the riynamometer were
imp pos
ele
FP
y 1 one by a sheel metai
yg an , d 31 show the
chamber The drawings on the major dimensions and features
following following
of of the
Chegmbiers,
j beg yee are also included
The
+
chamber we.
ae Through
pumped with inlet and outlet filters and a vacuum the enclosure Air entered the chamber through an
System to 8 in x
0 btatiaes 1 AA absolute fiber glass filter and was drawn out through
Two 8 *
oem, Hh pore membrane fillers
These were of 1.2 A
pose
core
Cal No. PA 1810 11
Air Flow was provided by two Hild vacuum
eleaners (ope aso. 145 and one model 765
Each had twe 1-1 HP motors -
ging ging oy tae ty
re
MANVILLE RESEARCH
AND ENGINEERINGENGINERING CENTERCENTER
Memorandum
MAS
MAS MAS
Page
CLEANED BRAKING BRAKING ASSEMBLY FILTER AMPLE COLLECTION COLLECTION COLLECTION
b Work at Cambridge
Data on the mineral content and particle size distribution in lung
material from 50 cases of exposure to asbestos dust at Rochdale has been collected together in the form of a report Work is also proceeding to ascertain whether fibrous dust plays any part in the genesis of asbestosis
Chromatographic examination of asbestosis body material has suggested
strongly that the protein envelope consists of collagen The pattern of laying down of the protein is now to be considered as this will give information of the mechanism of rupture of the envelope prior to the fracture of the fibre
Experiments on the injection of asbestosis bodies into the brains of animals have continued It has been shown that sterile chrysotile fibres can
result in the formation of asbestosis bodies within six months and that mature
but unsegmented bodies do not product any marked effects The results on the
injection of fragmented bodies are so far inconclusive The work continues
and has been extended to amosite and crocidolite fibres
7
DUST SAMPLING AND ANALYSIS
Continued experience of the Ottway instrument has shown that the dust
count obtained in a steady concentration is dependent upon the sampling time Evidence of this has been obtained by all three Member Companies but users of the instrument who are interested in fibrous dusts have not experienced this difficulty No simple reason for the phenomenon has been discovered and it is likely that the matter will not be resolved until more is known on the
physics of asbestos dust clouds
Work on mass sampling by membrane filters has commenced
8
RESEARCH COMMITTEE'S COMMENTS
The Research Committee feels that good progress has been made during the year but the rate of progress has been hampered by limitations of manpower
Approval has already been given for the provision of extra assistance for Dr. Holt at Reading and the new arrangements will come into force on 1st
October 1959. It is felt that in addition to expediting Dr. Holt's programme of work this appointment will enable a start to be made on investigating the physics of asbestos dust clouds Further proposals for expansion of the Council's Research Programme are under consideration
.
on
ASCBeers
August 2
1971
a NAT
CYLINDER
PUSH ROD
.
BOOT
}
r
WINDOW WINDOW
wd
FIGURE 2
a
WHEEL HUB
GASKET
INLET
FILTER
M450-429 M450-429 August 2
1971
MANOMETERS
1
in
|
& |
OUTLET FILTERS TO VACUUM
FIGURE 3
~{
|
30 30
|
J
fi JOHNSMANVILE MANVILLE MANVIL E MANVILME ANVMANVIILE LLE RESEA
7
AND ENGINESTINENGINEGSTING CENTEN CENTEN
Memorandum M456-47 M456-47
INLET OND DE CHAMBER
OM OMOM OM OM OM
Johns
Manville
Manville
Manville
Research & Engincering Center
\
O. Box 150 Manville NJ 08035 201 722-9000
W. W.
me is
L
AS Te LG eWhkis
ot
E.
B.
Brenneman
-Westinghouse -Westinghouse
-Westinghouse
I. Graham - CUQ
FJg
November 1 1971
}
written 10/29/71
4
Mr. William J. Harris Jr
' Vice President Association of American Railroads
; Research & Test Department
American Railroads Building
1920 L Street N.W.
>
Washington DC 20036
Dear Mr. Harris
x .
In my
letter that wear determine to
to tests
you of June 25 1971
would be performed performed on
I had COBRA
the extent to which chrysotile
pointed out
brake shoes fiber is re-
leased during service These These tests have been conducted
at the Westinghouse Air Brake Division under the super-
vision of JM Research personnel personnel and I would like to
the take this opportunity to inform you of
results
Westinghouse The
Air Brake Division railroad
in
simulate dynamometer PA Wilmerding was used to
tions for these tests In order
various service condito collect wear dust
wheel samples the
and braking braking
assembly
of
the
dynamometer
were completely enclosed by a sheet metal chamber
chamber was equipped with inlet inlet and outlet filters
The and a
vacuum system to draw through the enclosure Air entered
Flanders the chamber through Flanders
type AA absolute fiber glass
+
filter to assure that it was was clean
Air was drawn out of
.
the chamber through two 8 in x in Millipore membrane
filters 1.2u pore size Provision was also made to
measure the air flow through through the chamber the
in
the temperature chamber and the temperature temperature of the wheel
tread
Prior to each phase of testing testing the interior of the chamber
thoroughly was washed
down with cleanthoroughdly ry
with rags
mineral spirits and then wiped
The brake head head lever arm and
holts had been blasted prior to the start of testing
These were also cleaned carefully carefully before each test phase
All
rivets were covered with metalized metalized tape and all welds were
inspected for smoothness and and integrity The brake shoe was
thoroughly brushed before weighing weighing
wirebrushedbrushed
'
and the backer plate was
Four different test phases were
1 2
3
Passenger Commuter
car simulation simulation
run simulation
Grade simulation
4.
Heavy freight simulation simulation '
run
edeBAL Manville ,
Manville Manville
,
Research & Engineering Center
boo BoBox x 1593
!
\
Manville NJ 08835
!
2011 772 9000
.
1
;
:
te}
Mr. William J. Harris Jr
y
November1 1971
Page 2
At the completion of each phase all the dust in the chamber
and on the Millipore exit filters was collected combined
analysis microscope and submitted for chemical and electron microscopic
The electron
was used to determine the amount of
asbestos fiber in the dust
After analysis of the composite sample for each phase the
sample was separated
by air elutriation
below
into airborne and airborne fractions
The results of the analysis are given
;
Analysis Results of COBRA Dust Semple
1
}
Per Cent
Per Cent Asbestos Fiber
of Sample
Airborne
Total
Phase
Airborne
Fraction
Sample
;
1
2
3 7
4
20 20
7 12
0.0128
0.03
. 0.008
0.02
\
0.001
0.03
0.003
0.05
Finally calculatiown erse made to determine the amounts and
during phases a
percentages of recognizable
the various
asbestos fiber actually liberated
The results are as follows
an) ~
os
re
en
Wt of Fiber
.
Liberated 7
in
Entire
Phase
Entire Phase No. of Stops in Entire Phase
. .
wy,
.
~ 3
AWNP AWNP AWNP AWNP
.
0.006
10.003
0.016
0.007
1
grams
10
18
stops stops
from 80 mph
from various
speeds
Continuous minute drag
20 stops from 40 mph
20
In general our conclusiocnasn be stated as follows
Loy
,
is
chrysotile .
1
In almost all cases loss than 1.0 per cent of the original
:
-
fiber in the formula remains recognizable
chrysotile
. fiber in the wear dust
2
2 In instance less than 0.05
of
fiber remains as recognizable recognizable in the fraction of the dust
which is potentially airborne airborne
. ;
Mi Mi
M Mi i
Manville Johns Manville Manville
Manville
:
-.
.
,
Research & Engineering Center
PO Box 159
Manville N. 08335
201 722-9000
7
.
{ |
}
4
.
"
.
'
. Mr. . WiWiliam lliam J. Harris Jr
Jr
November 1 1971
Page 3
|
,
.
.
a
; a
These results are in good agreement with the previous work|
_ on automotive brake linings Furthermore they substanti-
ate the hypothesis that the extreme heat and mechanical
action the braking process is sufficient to all the fiber as it is exposed at the wearing sduersftarcoey almost
Please feel garding the
free
test
to contact me if you
procedures results
have any questions or conclusions
re-
Sincerely yours
.
\
}
,
'
BT\/
...:
wane - ... ... ...
:
;
.
F. LL.. Pundsack
Vice President Research & Development
ma
COPY
FORM
BOX NUMBER
02115 02115
SEGMENT NO NOTES
INITIALS
DATE
REQUESTING PARTY
* PARTY
COBRA RAILROAD BRAKE TESTS|
.
--
S.M WESTINGHOUSE 1971
^ VABCO
NAO INTERNAL CORRESPONDENCE WESTINGHOUSE AIR BRAKE DIVISION
DATE December 21 1971
TO J. A. CAMPBELL
K. CHRISSINGER
D. F. MCCONNELL f }
G. M. Cabble
R. A. MITCHELL J. W. MORRIS H. R. ODELL
SUBJECT ASBESTOS EMISSIONS TO THE ENVIRONMENT FROM COBRA SHOES
The Federal Government as well as some State and Local Governments
have become interested in pollution caused by many things one of which .
is asbestos We have been questioned by various groups and individuals
concerning the amount of asbestos fiber released by
braking action
In order to be able to answer these
COBRA Shoes during
questions COBRA
Shoe Engineering and Manville Research combined to run an
elaborate series of dynamometer tests during which all the wear dust
from various types of braking cycles was collected and analyzed
The results of these tests show that almost all of the asbestos fiber is
decomposed during brake applications
Less than one percent of the
original asbestos fiber in the shoe remains as fiber in the wear dust
and less than one tenth of that becomes airborne
Since each stop wears
only a very small amount of material contains only a very small percentage
that the amount of asbestos fiber that
,
from each shoe and since each shoe
of asbestos fiber
becomes airborne
it can be with each
seen
stop is
minute
Attached is a copy of ^ letter from Dr. F. L. Pundsack Vice Presi-
Research and Development Manville to Dr. W. J. Harris
Vice President and Test Association of American Railroads
and a copy of the reply
The first letter describes the tests and the
results while the reply transmits the AAR's reaction to this information
If any more detailed information regarding the tests is necessary con-
tact COBRA Shoe Sales
GMC
Attach
CC Atlanta
G. E. Carothers
Houston
D. T. Kerr
Philadelphia
E. Brenneman
St. Paul
J. C. Janke
.
.
H. M. Linhart
F. J. Grejda
:
W. I. Graham M
Research & Engineering Center
Bo Boxx 159
Manville N J. 08835 201 722.9000
Mr. William
November 1
Page 2
J. HarriJsr
1971
At the completion of each phase all the dust in the chamber
and and
The
on the Millipore exit filters was collected , combined submitted for chemical and electron electron microscopic analysis electron microscope was used to determine the amount of
asbestos fiber in the dust
After analysis of the composite sample for each phase the
sample was separated into airborne and airborne fractions
by air elutriation
,
The results of the analysis are given
below
Results of COBRA Dust Sample Analysis
Phase
AWNH AWNH
AWNH :
AWNH
Per Cent
of Sample
Airborne
20
20 7
12
Per Cent Asbestos Fiber
Airborne
Total
Fraction
Sample
0.012 0.008
0.001 0.003
0.03 0.02 0.03 0.05
Finally calculations were made determine the amounts amounts and
percentages of recognizable asbestos fiber actually liberated
-
during the various phases The results are as follows
Wt of Fiber
Liberated in
Phase
Entire Phase No. of Stops in Entire Phase
7.
AWNH
AWNH
*
AWNH
AWNH
0.006 0.003 0.016 0.007
grams
10 stops from 80 mph
18 stops from various speeds Continuous minute drag
20 stops from 40 mph
In general our conclusions can be stated as follows
1
2
In almost all cases lessless than 1.0 per cent of the original
fiber in the formula remains as recognizable chrysotile
fiber in the wear dust
;
In every instance less than 0.05
fiber remains as recognizable in which is potentially airborne
per the
cent of the
fractioonf
original
the dust
Manville
Research & Engineering Center
O. Box 159 Manville N. J 08835
201 722-9000
; -
Mr. William J. Harris Jr
November 1 1971 Page 3
These results are in good agreement with the previous work on automotive brake linings Furthermore they substantiate the hypothesis that the extreme heat and mechanical
action of the braking process is sufficient to destroy almost all the fiber as it is exposed at the wearing surface
surface
.
~~
Please feel
garding the
free test
to contact me if you
procedures results
have any questions or conclusions
re-
Sincerely yours
F. L. Pundsack Vice President Research & Development
*
OCIATION OF
ESEARCH AND TEST DEPARTMENT - AMERICAN RAILROADS BUILDING 1920 L STREET N.IX. WASHINGTON D.C. 20936 AREA CODE 3.1182
.
Mugrio
Mugrio Mugrio
Mugrio
WILLIAM HARRIS JR
Vice President
11/15/1711/15/71
.
with Mugfi rio
with rn
cc Mr G. Cabble -West Mr E. Brenneman -West
with
November 12 1971
,
W. I Graham
JA
JA
RETIARCH RETIARCH
RETIARCH RETIARCRH ETIARCH
Mr. F. L. Pundsack Vice President Research and Development
Research & Engineering Center
Manville
Box 159
Manville New Jersey 08835 |
.
Dear Mr. Pundsack
NP915 7
NP915
NP915 NP915 1971
F.
.
PUNDRACK PUNDRACK
?
.
.
It was very kind of you to write to me sending such helpful
information on the results of wear tests on COBRA Brake Shoes
Your studies clearly indicate the very small fraction of
_
material which is generated as a result of the tests and also the
even smaller fraction of the material which remains as
recog-
nizable chrysotile fiber in the wear dust
am very much hoping that we can lay this matter to rest but there are still clouds on the horizon concerning asbestos which
.
we shall be observing with the greatest care
If any further developments occur that you believe warrant our attention please write to me and I shall do the same
Again am deeply appreciative of the effort that you have expended in responding to my concerns on this subject I sincerely hope that these efforts will allow us to be fully responsive should
the need arise
cc R. Byrne AAR R. R. Manion AAR
J. A. Risendal
Sincerely yours
ra _f
)
(
m m LILLY
Railroad Friction Products CorporatioConrporation
'
Wilmerding Pennsylvania 15148
Date
To
From
SUBJECT
INTERNAL CORRESPONDENCE
March 22 1976
. .
W. I. Graham ^ 3526
.
xx.Zx.x.Z. 2
xx.Z.
M. M. Farnsworth
COBRA SHOES - ASBESTOS CONTENT INSURANCE
2945
Attached is a copy of a memorandum from Mr. Chanzis dated March
16 1976 relating to the decision of Travelers not to renew its coverage of insurance for Railroad Friction Products Corporation The basic 1,000,000 coverage will expire July 1 1976 the
increased coverage to 10,000,0 wh0ic0h became effective
April 1 1975 will expire April 1 1976
The decision of Travelers is based upon the asbestos content
the COBRA shoes Travelers has decided as a matter of policy to insure any products with asbestos content
of not
Also attached are copies of
Travelers letter of March 8 to Marsh &
Chanzis letter of February 18 to Marsh My memorandum of February 16 to Chanzis Cabble memorandum of December 21 1971
M letter of November 1 1971 to AAR AAR letter of November 12 1971 to M
McLennan & McLennan
all relating to asbestos emissions to the atmosphere from COBRA
shoes
Do you have any suggestions about where insurance coverage can
be obtained for RFPC Can you obtain any information about such
coverage from others in the M organization
MMF
ATTACHMENTS
cc E. W. Kojsza w copy Travelers letter of 3/8
WESTINGHOUSE AIR BRAKE COMPANY Specialists in Braking
MANVILLE CORPORATION
Specialists in friction Materials
ee
ry
JJM M
Manville Johns Johns
Manville Manville
Research & Engineering Center
O. Box 159 Manville J. 08835 201 722-9000
Mr. William J. Harris Jr. November 1 1971 Page 2
At the completion of each phase all the dust in the chamber
and on the Millipore exit filters was
and submitted for chemical and
collected combined
The electron
electron microscopic analysis
microscope was used to determine the amount of
asbestos fiber in the dust
After analysis of the composite sample for each phase the
sample was separated into airborne and airborne fractions
by air elutriation
below
The results of the analysis are given
:
.
Results of COBRA Dust Sample Analysis
Phase
723
723
723 4
Per Cent
of Sample Airborne
_
20 20
7 12
Per Cent Asbestos Fiber
Airborne
Total
Fraction
Sample
0.0128 0.008 0.001 0.003
0.03 - 0.02
0.03 0.05
Finally calculations were made to determine the amounts and percentages of recognizable asbestos fiber actually liberated during the various phases The results are as follows
e 2
~
Phase
123< 123< 123< 123<
Wt of Fiber Liberated in Entire Phase
ous
No.
of Stops
in
Entire
Entire
Phase
0.006 0.003 0.016 0.007
grams
_ ,
10 stops from 80 mph 18 stops from various speeds
Continuous minute drag
20 stops from 40 mph
In general our conclusions can be stated as follows
I.
2
2 .
In almost all cases less than 1.0 per cent of the originaloriginal original
fiber in the formula remains as recognizable chrysotile
fiber in the wear dust
In every instance less than 0.05
fiber remains as recognizable in which is potentially airborne
per
the
cent of the
fraction of
original
the dust
\
IM IM| IM
(
Manville Manville
Manville
Research & Engineering Center
O. Box 159
Manville 08935
.
;
201 722-9000 :
bcc
~
Cl Mr. George
ole -Westinghouse
Mr. E. B. Brenneman -Westinghouse
W. I. I. Graham - CHQ
.
.
* ;
November 1 1971
written 10/29/71
Mr. William J. Harris Jr Vice President Association
Research & Test Department
American Railroads Building
1920 L Street N.W.
Washington DC 20036
of American
Railroads
Dear Mr. Harris
x x
In my letter to you of June 25 1971 I had pointed out
that wear tests would be performed on COBRA brake shoes
to determine the extent to which chrysotile fiber is
leased during service These tests have been
re-
conducted
at the Westinghouse Air Brake Division under the
vision of JM Research personnel
and I would
superlike to take
this opportunity to inform you of the results
The Westinghouse Air Brake
Wilmerding PA was used to
tions for these tests In
Division simulate
order to
railroad dynamometer in
various service condicollect wear dust
braking samples the wheel and
were
assembly of the dynamometer
completely enclosed by a sheet metal chamber The
chamber was equipped with inlet and outlet filters and a
vacuum system to draw air through the enclosure Air entered
the chamber through a
filter to assure that
Flanders type AA absolute
it was clean clean Air
fiber
glass
the chamber through two in x 10 in Milliwpaosredrmaewmnbroaunte of
filters of 1.2 pore size Provision was also made
measure the air flow through the chamber the
to
the chamber and the temperature of the wheel temperature in
tread
Prior to each phase of testing the the interior of the chamber
was washed down
thoroughly
with
mineral mineral
spirits
and
then
wiped
with clean dry rags The brake brake head lever arm and
bolts had been blasted prior to the start of
These were also cleaned
testing
rivets were
carefully
covered with
before
each
test phase
All
metalized metalized tape and all welds were
inspected for smoothness and integrity integrity The brake shoe was
thoroughly brushed before weighing weighing and the backer plate was
brushed
Four different test phases were run run
1
2 3
Passenger car simulation
Commuter Commuter run simulation Grade simulation
4. Heavy freight simulation ;
subject
to
unit
location
N. B. Chanzis
Risk Management
New York
Department
from unit
location
M. M. Farnsworth
Transportation Systems
Pittsburgh |
Group
a2
RAILROAD ASBESTOS
FRICTION PRODUCTS EMISSIONS
February
CORPORATION
16
1976
of. vine
Referring to our discussions on February 12 copies of each of the following
I enclose two
2
G. M. Cabble memorandum dated December 21 1971
F. L. Pundsack letter dated November 1 1971 to
William J. Harris
W. J. Harris letter dated November 12 1971 to
F. L. Pundsack
all relating to asbestos emissions to the atmosphere from Cobra
shoes
Also enclosed are two 2 copies of
E456-2618 entitled Cobra Shoe Toxic
Manville report
Fume Investigation
No.
As I mentioned to you the person in the WABCO organization who
may be contacted for information in this matter is Mr. E. W.
Kojsza Manager Cobra Shoe Engineering He is in the Engineering Department of Westinghouse Air Brake Division Wilmerding Pa
The documents relating to asbestos emissions concern only the emissions from the shoes after they have been delivered by RFPC to the railroads transit systems for use on rolling stock That is as I see it the only place that RFPC would become involved in and have liability for asbestos emissions
The documents do not concern the asbestos emissions during the manufacturing operations by which Cobra shoes are produced Those operations are performed by M in M facilities M manufactures Cobra shoes to RFPC specifications under contract with RFPC
Enclosures
CC E. W. Kojsza w enclosures
WABCO
INTERNAL CORRESPONDENCE. WESTINGHOUSE AIR BRAKE DIVISION
ee
DATE December 21 1971
TO J. A. CAMPBELL K. CHRISSINGER
D. F. MCCONNELL
R. A. MITCHELL J. W. MORRIS H. R. ODELL
FROM G. M. Cabble
SUBJECT ASBESTOS EMISSIONS TO THE ENVIRONMENT FROM COBRA SHOES
The Federal Government as well as some State and Local Governments have become interested in pollution caused by many things one of which
is asbestos We have been questioned by various groups and individuals
concerning the amount of asbestos fiber released by COBRA Shoes during '
braking action In order to be able to answer these questions COBRA
Shoe Engineering and Manville Research combined to run an
elaborate series of dynamometer tests during which all the wear dust from various types of braking cycles was collected and analyzed
The results of these tests show that almost all of the asbestos fiber is
decomposed during brake applications
Less than one percent of the
original asbestos fiber in the shoe remains as fiber in the wear dust
and less than one tenth of that becomes airborne
Since each stop wears
onlya very small amount of material from each shoe and since each shoe
contains only a very small percentage of asbestos fiber it can be seen
that the amount of asbestos fiber that becomes airborne with each stop is .
minute
Attached is a copy of a letter from Dr. F. L. Pundsack Vice Presi-
_ Research and Development Manville to Dr. W. J. Harris
Vice President and Test Association of American Railroads
and a copy of the reply
The first letter describes the tests and the
results while the reply transmits the AAR's reaction to this information
If any more detailed information regarding the tests is necessary
tact COBRA Shoe Sales
con-
GMC Attach
CC
Atlanta Houston
Philadelphia
St. Paul H. M. Linhart
G. E. Carothers
D. T. Kerr
E. Brenneman
J. C. Janke
F. J. W. I.
Grejda -Graham M
on AMERICAN STANDARD COMPANY
SOCIATION
(
OF , AMERICAN SOCIATION AMERICAN
ot
.
C ? ?
.
. RAILROADS
- RESEARCH AND TEST DEPARTMENT AMERICAN RAILROADS BUILDING
1920 L STREET N.W. WASHINGTON D.C. 20036 AREA CODE 202 293 182
We
Lo
WILLIAMJ. HARRIS JR
Vice President
:
wholdwhold 11/15/1711/15/71Cents whold whold -West .
1/15/71
whold
whold
:
cc Mr G Cabble
Mr E. Brenneman
November 12 1971
-West
---- --... , Cents
---- --...
W. Il Graham
Mr. F. L. Pundsack Vice President
Research and Development Research & Engineering Center
Box 159
Manville New Jersey 08835 .
Dear Mr. Pundsack
7
N15 1971
.
.
_
It was very kind of you
information on the results of
to write to
wear tests
me sending such helpful
on COBRA Brake Shoes
Your studies clearly indicate the very small fraction of
material which is generated as a result of the tests and also the even smaller fraction of the material which remains as recog-
nizable chrysotile fiber in the wear dust
am very much hoping that we can lay this matter to rest
but there are still clouds on the horizon concerning asbestos which
we shall be observing with the greatest care
,
our
If any further developments attention please write to me
occur that you believe warrant and I shall do the same
Again am deeply appreciative of the effort that you have expended in responding to my concerns on this subject I sincerely hope that these efforts will allow us to be fully responsive should
the need arise
Sincerely yours
cc
R. Byrne AAR
R. R. Manion AAR
J. A. Risendal
yr
(
UM UM
Manville Johns Johns
Manville
Manville
Manville
Research & Engineering Center
O. Box 159 Manville N. J. 09835 2011322.9000 2011322.9000
|
.
Mr. William J. Harris Jr November 1 1971
Page 2
At the completion of each phase all the dust in the
and
ry
on
the Millipore
exit
filters
was
collected
chamber
combined
Tahned seulbemcittrtoend for chemical and electron microscopic analysis
microscope was used to determine the amount of
asbestos fiber in the dust
After analysis of the composite sample for each phase the
sample was separated into airborne and airborne fractions
by air elutriation below
The results of the analysis are given
.
.
\
:
oe
, .
Results of COBRA Dust Sample Analysis
Phase
123 123 123 4
Per Cent
of Sample Airborne
20 20
7 12
Per Cent Asbestos Fiber
Airborne
Total
Fraction
Sample
- 0.012 0.008 0.001 0.003
0.038 0.02 0.03 0.05
Finally calculations were made to determine the amounts and
percentages of recognizable asbestos fiber
during the various phases
actually liberated
The results are as follows
od
Phase
=
.
1
2
*
3
4
Wt of Fiber
Liberated in
Entire Phase
> Pry
Entire
No. of Stops in Entire Phase
0.006 0.003 0.016 0.007
grams
_ .
10
18
stops stops
from from
80 mph |
various
speeds
Continuous minute drag
20 stops from 40 mph
In general our conclusions can be stated as follows
1
2
2 .
In almost all cases less than 1.0 per cent of the original original fiber in the formula remains as recognizable chrysotile
fiber in the wear dust
In every instance less than 0.05
fiber remains as recognizable in which is potentially airborne
per the
cent of the
fraction of
original the dust
Manville
Research & Engineering Center
O. Box 159
Manville N. J 02835
201 722-9000
os
, :
os
Mr. William J. Harris Jr
November 1 1971 Page 3
ry
These results are in good agreement with the
on automotive brake linings
ate the hypothesis that the
previous work Furthermore they substanti-
action of the
extreme heat and mechanical
braking process is sufficient to
all the fiber as it is exposed at the wearing sduersftarcoey almost
Please feel garding the
free to contact me if you
test procedures results
.
have any questions or conclusions
re-
Sincerely yours
F. L. Pundsack
Vice President Research & Development