Accession Number:

AD0499380

Title:

8-In./55 Caliber CA-139 Class Pilot Turret. The Investigation of Torching in the 8-in./55 Caliber CA-139 Class Pilot Turret.

Descriptive Note:

Partial rept. nos. 12 and 2,

Corporate Author:

NAVAL PROVING GROUND DAHLGREN VA

Personal Author(s):

• Hanna, H. A.

Report Date:

1950-01-16

Pagination or Media Count:

32.0

Abstract:

Torching is the burning of the combustible components of the residual gases in the cartridge case following extraction and exposure of the case and gases to a source of oxygen air the source of the ignition is hot areas of the cartridge case. The hot areas of the cartridge case are a result of fluting of the case during firing. The fluted areas are extremely hot on extraction because, being bent inward from the chamber wall, little cooling by conduction to the gun liner is possible while the case is in the chamber. When these fluted areas are large enough, their temperature upon extraction can be as high as 1500 to 1700 F. If the temperature of any portion of the case mouth is above 1400 F approximately the ignition of the residual gases in the case is probable. Fluting, hence torching, is most prevalent in worn guns. The frequency and degree of fluting increases as gun wear increases. Fluting is more frequent and severe with reduced charges than with full charges. Practically no fluting is experienced with either full or reduced charges in a new gun.

Descriptors:

• *CARTRIDGE CASES
• *EXPLOSION GASES
• NAVAL GUNS
• AUTOIGNITION
• COOLING
• LIFE EXPECTANCY(SERVICE LIFE)
• GUN PROPELLANTS
• HAZARDS
• GUN BARRELS
• DEGRADATION
• THERMAL INSULATION
• SPACERS
• POTASSIUM COMPOUNDS
• SULFATES
• EXPLOSIVE CHARGES
• GUN TURRETS

Subject Categories:

• Ammunition and Explosives
• Armor

Distribution Statement:

APPROVED FOR PUBLIC RELEASE