I randomly accessed my files this morning and found the tug Herakles, which had once been a UK Emergency Towing Vessel, both with this name and an earlier one as Anglian Prince. Before that it was the Hispanic and originally the Salvageman, built in 1980. Back in those days it was a powerful vessel with 4 Rustons (pity the engineers) developing 11200 bhp. This gave it a bollard pull of 160 tons. It appears to be still at work off the coast of Denmark. 

The photograph was taken in 2011 against the wonderful backdrop of Valetta Harbour by Gaetano Spiteri and posted here on 9th June 2017.