SS Kielce

SS "Kielce was a Polish-operated cargo ship. She was a Type N3-S-A2 steamship, built in the USA in 1943 as SS "Edgar Wakeman.
In 1946 while laden with a cargo of munitions she sank in the English Channel after colliding with the French or British steamer "Lombardy".
In 1967 an attempt to salvage her wreck detonated some of her cargo, causing a minor earthquake.
History.
Pennsylvania Shipyards, Inc built "Edgar Wakeman" at Beaumont, Texas, completing her in 1943. She was an oil-burning steamship: a variant of the Type N3 design built at the request of the UK Government.
In 1944 the US War Shipping Administration bareboat chartered her to the Polish government-in-exile, who renamed her after the city of Kielce in Małopolska. In April 1944 "Kielce" sailed in Convoy HK 217 from Galveston to Key West, Convoy KN 308 from Key West to New York and Convoy HX 289 from New York to Liverpool. From then until April 1945 she took part in short-distance convoys in UK home waters.
On 5 March 1946 "Kielce" was in the English Channel off Folkestone carrying a cargo of munitions from Southampton to Bremerhaven when she collided with the steamer "Lombardy". "Kielce" sank about four miles offshore, in water about deep. Fortunately, there were no casualties, and all crew members were rescued by "Lombardy".
Explosion.
In 1966 the Folkestone Salvage Company was contracted to clear the wreck and disperse her explosive cargo. In 1967 the salvage company tried to dismantle part of the hull by setting explosive charges. On 22 July 1967 the third of these charges detonated some of her cargo. The resulting explosion damaged ceilings and chimneys and dislodged roof slates in Folkestone. A few windows were broken by movement of their frames. Nobody was injured.
It was claimed that the explosion "brought panic to Folkestone’s town and chaos to the beaches", and a few sources claimed that it caused a "tidal wave". In fact two employees of the salvage company in a small boat only about from the wreck witnessed only "a small ripple and some spray", and it is calculated that the resulting sea wave cannot have been more than high.
The explosion was recorded by 25 seismic recording stations, some of them up to away. From their recordings the explosion is estimated to have been about 4.5 on the Richter scale. It left a crater on the seabed long, wide and deep.