FINAL REPORT ON SPRING STUDY UNDER R. O. 3

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78-03642A000700050012-6
• Release Decision: RIPPUB
• Original Classification: C
• Document Page Count: 3
• Document Creation Date: December 22, 2016
• Document Release Date: May 24, 2011
• Sequence Number: 12
• Publication Date: April 20, 1959
• Content Type: REPORT

Sanitized Copy Approved for Release 2011/05/24 :CIA-RDP78-03642A000700050012-6
CONFIDENTIAL "ter" r ~n
R. 0. 5
'q A2 0 /5-7
INTRODUCTION '
Under a preceding task (Contract RD 45, R. 0. 22, 16 September
1955 to 15 March 1956), the complete destruction of the Mk 2 Delay
Unit was studied employing various materials for body, striker
and spring, and testing their physical and chemical decay under
influence of the incendiary or explosive attachment.
Under this assignment, one hundred phosphor-bronze springs,
especially designed for the Mk 2 Delay were purchased from the
Muehlhansen Spring Division of Rockwell & Axle Co. Since tests
showed their usability in the Mk 2 Delay as well as their essential
destruction by fire and explosion, a long-term study was agreed
upon to determine the amount of set or fatigue under prolonged
static load conditions. This task was awarded under a work order
(Contract RD 45, R. 0. 5, Letter of 28 June 1956) but the prepara-
tion of the springs in compressing them in striker assembly was
begun under the preceding task in October 1955. The testing
was completed in October 1957 but additional springs were kept
in ambient storage until April 1959 and measurements were taken
then.
Six sets of ten springs each were assembled into a test fixture
resembling closely the actual striker assembly of the Mk 2 unit
and the free strength and free length for each spring were checked
before and after the treatment which consisted of the following --
one condition for each group:
CONFIDENTIAL
25X1
25X1
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 Sanitized Copy Approved for Release 2011/05/24: CIA-RDP78-03642A000700050012-6
1 CONFIDENTIAL
a. temperature and humidity cycle according to
"JAN Cycle" MIL-STD-504,
b. storage at 75?F for one month
three months
six months
twelve months
twenty four months
After each period, a retest of strength and length was per-
formed. There were no significant changes on any one test. A
final recheck was made after an additional year using unused, fully
compressed springs and springs which had been compressed before.
The nominal length of the springs was 49/64" t 0.039" or minimum
0.7270, maximum 0.8059.
The following were the results:
uncompressed
formerly compressed
continuously
compressed
.773
.761
.733
.764
.742
.729
.764
.752
.750
.767
.752
.726
.771
.747
.729
average
.768
.751
.733
This test confirms the former findings. The springs which had.
been compressed for three years differed by -0.055 in. or -4
from the original, the figure lying within the permissible
tolerances.
After completion of the two year period, five of the springs,
stored in compressed state were assembled in Mk 2 Delay Units and
tested using the acetone capsule with the Incendiary Head (P-Unit).
All five fired satisfactorily.
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CONFIDENTIAL
Another teat was set up using M54 detonators with Mk 2 Delay
Units but for obscure reason, the firing did not take place and
the test items had to be destroyed by extraneous means.
CONFIDENTIAL
Sanitized Copy Approved for Release 2011/05/24: CIA-RDP78-03642A000700050012-6