This one I snapped in Ipswich 'Fenland' is important nationally so if anyone knows more then please get in touch with this organisation http://www.nationalhistoricships.org.uk/ships_register.php?action=ship&id=2355
An unusual tug Fob Junior twixt HRH & FXT is more of an offshore supply vessel than a tug see here http://www.fob-shipping.com/2.html