ATD Tugs 2412 "ZP Bear" and "ZP Bison" Damen Shipyards Group delivered two sister tugs ATD 2412 ‘ZP Bison’ and ‘ZP Bear’ to strengthen KOTUG’s European Harbour Towage. On April 8th 2015, the sister tugs were handed over by designer and builder Damen to her owner Elisabeth Ltd. in order to operate for KOTUG. ZP Bison will operate in the Port of Bremerhaven and ZP Bear on the River Thames in London. See all deliveries