A ship laden with potentially explosive cargo remains at anchor off the Kent coast – despite being due in Malta on Friday. Ruby – a Maltese-owned and flagged vessel – is carrying about 20,000 tonnes of ammonium nitrate from Russia but suffered damage soon after leaving port on August 22. Since September 25, she has been at an anchorage point about 15 miles off Margate – but in international waters – and being monitored by the UK Coastguard. According to VesselFinder, a global ship tracking website, the 2012-built ship was expected to arrive in Malta at 6pm on Friday. But she remains in place o…