As dockworkers’ unions warn of impending industrial action at ports that would cripple our Christmas, eerily similar parallels can be drawn to the chaos wrought by strikes across London’s docks in 1889.More than 100,000 people took part in those strikes more than 130 years ago, closing one of Britain’s busiest shipping destinations – the Port of London – for more 20 days and winning a famous ‘docker’s tanner’, a pay increase of sixpence per day, and earning them huge swathes of public support.