Big Bertha started her working life under the sea a century ago and ended it yesterday up in the air.

Bertha is a 5.5-tonne Messa electric-powered compressor made in Germany in 1908 - the same year Henry Ford started producing his Model T in Detroit - and installed in a World War I submarine.

U-boats were effective weapons for Germany in the 1914-18 war. Of the 360 sub marines built, 178 were lost - but they sank over 5000 Allied ships.

In 1917, Bertha was taken to Britain as a prize of war and was used in industry before being brought to New Zealand for Mason-Mesco and used to manufacture oxygen until 1970, when she was considered to be at the end of her productive life.


It looked like the end of the line for the old compressor, which was parked in an Auckland paddock until Colin Wilcox rescued her from the long grass and brought her to Whangarei in 1975.

After 18 months of restoration, Bertha began a new life in the Sub Aqua Dive Centre in the city's Cameron St, moving to Dive HQ in Clyde St in 1980.

For the past 32 years, the huge single-cylinder compressor has been turning over slowly, filling untold thousands of 80cu ft dive tanks with air in 40 seconds.

But Dive HQ boss Kevin Hobbs said retirement loomed after the compressor's motor had caught fire. It would have cost $12,000 to replace burned parts and the 104-year-old machine was already costly to maintain.

Some parts were removed and Bertha was headed for the scrap heap until marine insurance assessor Sholto McCardle stepped in to save her, arranging for Atlas Cranes to donate a 60-tonne crane to lift the old compressor through the Dive HQ roof after Dixon Roofing had lifted the iron clear.

Ensura Building Services supplied a building and Northland Contract Boatbuilding provided store space for Bertha while the Packard and Pioneer Museum at Maungatapere decides whether it has room to offer her a home.

"If she doesn't go there the maritime museum at the Navy dockyard at Devonport in Auckland is interested in her," Mr McCardle said.

Meanwhile back at Dive HQ, they are filling dive bottles with a temporary compressor while they wait for the delivery of a small new machine with a 22cu ft a minute capacity, compared with Big Bertha's compression strength of 120cu ft a minute.