Black Cat Terminal Akaroa

A Bryn Martin Project

black cat

The Challenge


Black Cat Cruises is a well established eco-tourism operator in Canterbury. Akaroa is one of their operating locations, and is best known for Black Cat's "swim with dolphins" experience.

With the growth in tourist numbers and the success of the Akaroa operation, it became necessary to redevelop the terminal at Main Wharf, Akaroa.
Initially Bryn Martin was asked to provide design services for the pumped effluent disposal only, but within a short time we worked with Black Cat to widen the scope to cover hot and cold water supplies, ventilation, and central heating.
Both timeframe for construction and the available budget were tight.

Main Features

  • The existing building had only one shower.
  • Hot water came from a conventional electric water cylinder.
  • Heating was provided to the front booking office and shop area only.
  • Wet suit drying facilities were basic.
  • A limited electrical supply to the Terminal.


The Response


Bryn Martin obtained from EECA a 40% grant to allow a proper energy study to be carried out before detailed design works started. We looked at the relative merits of heat pumps, a wood pellet heat source, heat pumps for domestic hot water, heat recovery from the ventilation, and heat recovery from the drains.

Picture1The Works

The conclusion of the energy study was that the least costly and most energy efficient solution would be to:

  • Install a 35kW wood pellet boiler.
  • Provide all domestic water heating via a plate heat exchanger coupled to 800l of storage.
  • Use a heat recovery ventilation unit with a low temperature hot water boost coil to ventilate all of the "wet" areas. (13 showers, toilets, wet-suit drying). The ventilation unit recovers approximately 70% of the heat in the outgoing air to pre-heat the incoming air.
  • Use low temperature hot water fan coil units to provide heating to all parts of the Terminal.
  • Underfloor heating in the shower areas.
  • Re-use of the exiting foul water drainage pumps but in much larger holding tanks (capable of holding the foul water discharges from the cruise boats as well as the Terminal), installed in a very low space beneath the wharf deck.

The Frohling boiler is an ultra-low emissions device from Frohling in Austria. It has operated to Black Cat's satisfaction from the outset.
The redeveloped terminal is warm, dry, and well ventilated. Wet suits can be dried rapidly, and the hot water system can supply 30 showers an hour indefinitely, essential to meet peak use.
By adopting a wood pellet option, a costly replacement of the Terminals electrical feed has been avoided.

Now that most of the Terminal's former electrical load has been provided for with environmentally friendly, carbon neutral wood pellets, the remaining load (essentially computers and lighting) can be provided from photo-voltaic panels and a limited amount of storage.
This is a likely future development which will allow the terminal to achieve a long term zero electrical use.