NVIC 04-70: Black powder loads for Lyle line-throwing guns

DEPARTMENT OF TRANSPORTATION UNITED STATES COAST GUARD Address reply to: COMMANDANT (MMT-3) U.S. COAST GUARD WASHINGTON, D.C. 20591 NVIC 4-70 15 JUN 1970 NAVIGATION AND VESSEL INSPECTION CIRCULAR NO. 4-70 Subj: Powder Loads for Lyle Type Line Throwing Guns

Powder Loads for Lyle Type Line-Throwing Guns — Purpose. This circular is intended to inform the users of Lyle guns of the fact that many suppliers of the powder for the gun may in fact be furnishing modern high-explosive gunpowder in place of the genuine black powder actually required. This could create a hazardous condition for the personnel firing the gun.

Purpose. This circular is intended to inform the users of Lyle guns of the fact that many suppliers of the powder for the gun may in fact be furnishing modern high-explosive gunpowder in place of the genuine black powder actually required. This could create a hazardous condition for the personnel firing the gun.

Powder Loads for Lyle Type Line-Throwing Guns — Background. The vessel regulations permit the continued carriage of the Lyle gun type line-throwing appliance on vessels contracted for prior to 10 November 1952 if the appliance was already in service on such vessels and it is in good and serviceable condition. The required equipment includes eighteen bags (2 1/2 ounces each) of black powder marked "one-half normal charge for Lyle gun, 2 1/2 ounces black powder". Present firearms control regulatio

2. Background. The vessel regulations permit the continued carriage of the Lyle gun type line-throwing appliance on vessels contracted for prior to 10 November 1952 if the appliance was already in service on such vessels and it is in good and serviceable condition. The required equipment includes eighteen bags (2 1/2 ounces each) of black powder marked "one-half normal charge for Lyle gun, 2 1/2 ounces black powder". Present firearms control regulations make it increasingly difficult for suppliers to store and ship black powder, and as a result, many are supplying high-explosive gunpowder in lieu of the genuine black powder for which the Lyle gun was originally designed.

Powder Loads for Lyle Type Line-Throwing Guns — Discussion. The modern high-explosive gunpowder develops considerably more force for a given amount than does black powder. The practice of increasing powder loads to achieve greater ranges when firing the gun's line throwing projectile is a practice that is acceptable only with black powder. If modern high-explosive gunpowder is used under the same circumstances, the Lyle gun will be in danger of bursting from the higher internal pressures generat

3. Discussion. The modern high-explosive gunpowder develops considerably more force for a given amount than does black powder. The practice of increasing powder loads to achieve greater ranges when firing the gun's line throwing projectile is a practice that is acceptable only with black powder. If modern high-explosive gunpowder is used under the same circumstances, the Lyle gun will be in danger of bursting from the higher internal pressures generated. For this reason, all modern high-explosive gunpowders are unacceptable and great precautions must be exercised to insure that all powder loads delivered to a ship for a Lyle gun are in fact genuine black powder and bagged in loads of the amounts originally intended.

Powder Loads for Lyle Type Line-Throwing Guns — Action. All persons responsible for firing a Lyle gun should take precautions to insure that it will not be loaded with modern high-explosive gunpowder. All supply requests for powder loads intended for a Lyle gun should specify that only genuine black powder is acceptable.

J. B. McCARTY, Jr. Captain, U.S. Coast Guard Acting Chief, Office of Merchant Marine Safety Dist: (SDL No. 90) A: None B: n(45); c(10); q(6); eg(5); bg(1) C: m(4); o(2) D: i(2); k(1) E: ho(2) F: None List 112-155