McKay was engaged by Damen Shipyards, Netherlands and Ports of Auckland to design and supply the vessels charging infrastructure, while ensuring compliance to New Zealand Regulations.
Sparky is a 24.73m electric tug boat with a beam of 13.13m, a draught of 6m, and a speed of 12 knots, capable of pulling 70 tonnes.
The vessel draws power from 2,240 LTO batteries with a total rated output of 2,784kWh, which enable the tug to achieve CO2 emissions of approximately 465 tonnes each year with operational costs being less than one third of the costs associated with operating a diesel tug.
To ensure safety, Sparky also has two 1000kW backup generator sets, which will only be used in cases of emergency.
Designed to complete four shipping moves on a single charge of its batteries, while recharging in approximately two hours, McKay’s automation and control engineers worked closely with Damen and Ports of Auckland to meet their specific requirements. This included gaining componentry approval for the electrical switchboard to assist with compliance with New Zealand rules and regulations.
Additionally, McKay provided certified LV earthing design for the charging infrastructure, plus:
• The design integration between the Damen switchboard and LV circuit isolation.
• The design for the LV power and lighting switchboard for the substation.
• Complete electric installation on site including termination of the charging arm.
• The electrical installation of the tug’s onboard HVAC setup.
Sparky’s charging infrastructure includes a wharf side substation and charging arm that houses 4 charging cables complete with CCS2 HP plugs that connect to Sparky’s connection plate, manually by the ship’s engineer.
The substation has an 11kV supply to the 2MVA transformer housed inside, providing a step-down to 690VAC which powers the Damen Switchboard. Within the switchboard, the 690VAC is rectified to 1050DC, providing the 1.5MW via the 4 charging cables to charge the vessel.
The charging cables and plugs are glycol cooled and the CCS2 plugs have continuous temperature monitoring housed within.
