View source for Shellite (explosive)

[[file:HMAS Australia 12 inch shells Closeup.JPG|thumb|right|British, 12 inch shells displayed at the [[Royal Australian Navy Heritage Centre]] (2008). On the right is a Mk 6A Capped Common pointed shell, (formerly) filled with Shellite 70/30]]

'''Shellite''' (known as '''Tridite''' in US service<ref>Meyer ''et al'', p.417</ref>) 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]] [[Shell (projectile)|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.<ref>Preston et al, p.83</ref> 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.<ref name="Zukas">Zukas et al, p.38</ref> The first trials of shellite took place in 1921, when the British [[Monitor (warship)|monitor]] {{HMS|Terror|I03|6}} experimentally fired different types of [[BL 15 inch Mk I naval gun|15 inch (381 mm) shell]] at {{convert|500|yd|m|adj=on}}, point-blank range against the surrendered German battleship {{SMS|Baden}}.<ref name="Zukas" />

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 [[shipwreck|wrecks]] of sunken [[warships]]. They are considered hazardous as, over time, picric acid will react to form [[crystal]]s of metal [[picrate]]s, such as [[iron picrate]]. These crystals are extremely shock sensitive and it is recommended that wrecks that contain shellite [[munition]]s not be disturbed in any way.<ref name="allbright78">Albright, p.78</ref> The hazard may reduce when the shells become corroded enough to admit [[seawater]] as these materials are [[water-soluble]].<ref name="allbright78" />

==References==
;Citations
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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}}

[[Category:Explosives]]
[[Category:Naval artillery]]