On 27 October 1986, Adm. Nyquist, who had been involved with the IM policy from the beginning, issued an amplification to the Insensitive Munitions Council decisions and on the Navy policy to retrofit munitions to make them meet the IM requirements. His memo stated:77
“… We have a procedure to petition the SCIB for a waiver if there are reasons to not make a munition insensitive. The reasons include lack of technology, prohibitive cost, and urgent operational requirements.”
RAdm. Flatley, the Acting Director, Naval Warfare (OP-95) in a memo of 17 November 1986 offered the following clarification:78
“The thrust of the policy is simply this: we will only retrofit existing inventories when it makes good operational and fiscal sense to do so; i.e., a fix is available, effective, affordable, and can be installed during the normal weapon maintenance cycle.”
The above memos again reflected the difficulties encountered in the implementation of the IM policy and technical requirements as first issued — particularly the goal of making all munitions insensitive by 1995. It became clear early in the program that some of the technical requirements for insensitive munitions would be very difficult, if not impossible, to meet with the technology available then.
Driven by the IM requirements, however, the Navy laboratories performed numerous tests and acquired a great deal of data on the sensitivity of Navy munitions — data that were not available at the time of the CEB presentation. Also, with a well-funded advanced development program, new explosive, propulsion, and ordnance design technology began to appear and applications soon followed.
Although many munitions still could not meet all of the IM requirements, the new technology available made it possible to make vast improvements in sensitivity of munitions to heat, bullet, and fragment attack. For large munitions like general-purpose bombs and naval torpedoes, sympathetic detonation in the shipboard storage configuration remained a problem. On ships where it was possible to do so, storing torpedoes in a nose to tail configuration tempered the sympathetic detonation problem.
77Nyquist, J.W. RAdm., Assistant Deputy Chief of Naval Operations (Surface Warfare), Memo 03/6U5739 of 27 October 1986,; Subject: Insensitive Munitions (IM).
78Flatley III, J. H., RAdm., Director, Naval Warfare (Acting), Memorandum for distribution, Ser. 954H1/6U159565 of 17 November 1986; Subject: Insensitive Munitions.