More recently SOLAS has been amended to bring an increased focus on maritime security through the International Ship and Port Facility Security (ISPS) Code. The IMO has also increased its focus on smoke emissions from ships. In January 1959, IMO began to maintain and promote the 1954 OILPOL Convention. Under the guidance of IMO, the convention was amended in 1962, 1969, and 1971. As oil trade and industry developed, many people in the industry began to recognise a need for further improvements in regards to oil pollution prevention at sea. This became increasingly apparent in 1967, when the tanker "Torrey Canyon" spilled 120,000 tons of crude oil when it ran aground entering the English Channel  The "Torrey Canyon" grounding was the largest oil pollution incident recorded up to that time. This incident prompted a series of new conventions. IMO held an emergency session of its Council to deal with the need to readdress regulations pertaining to maritime pollution. In 1969, the IMO Assembly decided to host an international gathering in 1973 dedicated to this issue. The goal at hand was to develop an international agreement for controlling general environmental contamination by ships when out at sea. During the next few years IMO brought to the forefront a series of measures designed to prevent large ship accidents and to minimise their effects. It also detailed how to deal with the environmental threat caused by routine ship duties such as the cleaning of oil cargo tanks or the disposal of engine room wastes. By tonnage, the aforementioned was a bigger problem than accidental pollution. The most significant thing to come out of this conference was the International Convention for the Prevention of Pollution from Ships, 1973. It covers not only accidental and operational oil pollution but also different types of pollution by chemicals, goods in packaged form, sewage, garbage and air pollution. The original MARPOL was signed on 17 February 1973, but did not come into force due to lack of ratifications. The current convention is a combination of 1973 Convention and the 1978 Protocol. It entered into force on 2 October 1983. As of May 2013, 152 states, representing 99.2 per cent of the world's shipping tonnage, are involved in the convention. In 1983 the IMO established the World Maritime University in Malmö, Sweden. The IMO headquarters are located in a large purpose-built building facing the River Thames on the Albert Embankment, in Lambeth, London. The organisation moved into its new headquarters in late 1982, with the building being officially opened by Queen Elizabeth II on 17 May 1983.