Shellite (explosive)
file:HMAS Australia 12 inch shells Closeup.JPG (2008). On the right is a Mk 6A Capped Common pointed shell, (formerly) filled with Shellite 70/30]]
Shellite (known as Tridite in US serviceMeyer et al, p.417) is an explosive mixture of picric acid and dinitrophenol or picric acid and hexanitrodiphenylamine in a ratio of 70/30. It was typically used as a filling in Royal Navy armour-piercing shells during the early part of the 20th century.
History
Shellite originated after World War I as a development of lyddite (picric acid). During the war, lyddite-filled, armour-piercing shells had been found to be shock-sensitive, with a tendency to prematurely detonate upon impact rather than after penetrating the target's armour plate.Preston et al, p.83 Shellite was less sensitive, and also had the advantage of a low melting point, that allowed it to be easily melted and poured into shell casings during manufacture.Zukas et al, p.38 The first trials of shellite took place in 1921, when the British monitor {{HMS|Terror|I03|6}} experimentally fired different types of 15 inch (381 mm) shell at {{convert|500|yd|m|adj=on}}, point-blank range against the surrendered German battleship {{SMS|Baden}}.
During World War II, Shellite continued to be used in naval shells. It was used in the British Disney bomb, a type of concrete-piercing bomb.
Legacy
Shellite-filled munitions may still be encountered in the wrecks of sunken warships. They are considered hazardous as, over time, picric acid will react to form crystals of metal picrates, such as iron picrate. These crystals are extremely shock sensitive and it is recommended that wrecks that contain shellite munitions not be disturbed in any way.Albright, p.78 The hazard may reduce when the shells become corroded enough to admit seawater as these materials are water-soluble.
References
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;Bibliography
- {{Cite book |last=Albright |first=Richard D. |url=https://www.worldcat.org/oclc/770664959 |title=Cleanup of chemical and explosive munitions : location, identification and environmental remediation |date=2011 |publisher=William Andrew |isbn=978-1-4377-3477-5 |edition=2nd|location=Norwich, N.Y. |oclc=770664959}}
- {{cite book | title=Explosives | publisher=John Wiley and Sons | author1=Meyer, Rodolf | author2=Kohler, Josef| author3=Homberg, Axel| year=2008|isbn=978-3527616343}}
- {{cite book | title=Warship | publisher=Naval Institute Press | author1=Preston, Antony | author2=Jordan, John| author3=Dent, Stephen| year=2007|isbn=978-1844860418}}
- {{cite book | title=Explosive Effects and Applications | publisher=Springer | author1=Zukas, Jonas |author2=Walters, William W. |author3=Walters, William P. | year=2002|isbn=0387955585}}