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Table 5.1 Explosion shot times on 29 September 1987 and pressure pulse arrival recorded at RHAS Goosander
Charge Vater Shot time b
Pressure eulse Goosander
Shot size depth a
GMT Travel time Distance c
standoff Comments
lb m h:m:s s m m
1 4500 76.13(!:.1) 11:52:33.2252(!lms) 0.3452 514.44 508.78 a precursor arrives about 18.8 ms
before the main pressure pulse and
extends up to it, the start of the
main pressure pulse is therefore
arbitrary to a few ms.
2 900 76.13(!.1) 15:22:30.5910(!lms) 0.1759 262.19 250.89 a tiny precursor arrives about
9.1 ms before the very sharp onset
of the main compression pulse.
a. Both explosions were detonated at the same position. A sonar depth of 76.25 m was measured on September 20 and 76 m on
September 29. Depth of 76.125 m used to calculate standoff. All Table entries are rounded to less than the precision
used in the calculations.
b. Measured from jet pen playout of the shot sequence timer channel recorded on Store 7 on RMAS Goosander. Individual
measurements taken from the jet pen playout good to +.25ms. Maximum alignment difference between second markers noted on
playout of MSF and DCF radio time channels from Store 7 recorder was 2 ms. The main pressure pulse was recorded sharply
on sequence timer, hydrophone, geophone, MSF and DCF channels of Store 7; the largest difference between shot time
measured on any of these channels and the above is 0.8 ms.
c. Calculated using 1.4902 km s-l as the velocity of sound in sea water at 10 0 C (Kaye & Laby 198?).