Tug 'Alerta' (left), registration LX-76-RL, bracing and towing alongside tug 'Zézito', registration LX-86-RL, and heading for the Alcântara docks (Lisbon harbour).

Main characteristics - tug 'Alerta':
Callsign: not available
LOA: 17,08 m
Beam: 4,30 m
Draft: 2,50 m
DWT: 33,08 t
Main engine: Caterpillar 435 cv 1800 rpm
Traction (max): 7 t
Year of Build: 1913
Builder: Gröninguen (Holland)
Flag: Portugal
Home port: Lisbon
Owner & Manager: Resistência (Lutamar Group)

Main characteristics - tug 'Zézito':
Callsign: not available
LOA: 11,22 m
Beam: 3,26 m
Draught: 2,20 m
GT: 16,06 t
Main engine: 1 x Diesel Cummins engine, 190 bhp @ 1800 rpm
Max. traction: 4 t
Flag: Portugal
Home port: Lisbon, Portugal
Owner & Manager: Lutamar Group (Lisbon, Portugal)