Albert Park Tunnels - Construction and Structure

Construction and Structure

There are more than 3.5 kilometres of tunnels, reaching from Constitution Hill to Wellesley Street, involving a network of shelters, sanitation facilities and first aid posts, all ventilated by air shafts, with a total of nine entrances. The tunnels run through sandstone and volcanic rock, and were mainly dug by hand by a team of 114 council workers, most of whom were middle-aged men who were unfit for war. The tunnels were lined with over 975km of native New Zealand native timber, including Kauri, Heart Rimu, Larch and New Zealand Stringy Bark. A total of 315 people were involved with this project.

The central, arched access tunnels were 9 ft high (2.7 m), 15 ft wide (4.6 m), and 3,700 ft long (1,100 m); the grid of accommodation galleries – totalling 6,000 ft (1,800 m) – were 7 ft (2.1 m) square and provided with wooden seating. The floors were covered with scoria.

The tunnel complex, unlike many other air raid shelter complexes, does not have blast doors, but instead has baffles. The baffle is a block in a tunnel constructed from wood, lead and stone to absorb the shock wave in the event of a bomb blast. The small tunnels around them allowed passage and reduced the shock with the perpendicular reflections. In 1941, baffles had been added to the twenty-year-old Parnell tunnel.

A diesel engine from an old meatworks powered the ventailation fans and emergency lighting, as well as a loud-speaker system.

• Illustrations of ‘baffles’

• Enlargement of Altern Rd entrance to tunnel complex with three ‘baffles’ encompassed inside red box

• Enlargement of entrances 3, 4 & 5 to tunnel complex with three individual ‘baffles’ isolated in red boxes

• Enlargement of entrance 2 to tunnel complex with ‘baffle’ isolated in red box

• Enlargement of entrance 1 to tunnel complex with ‘baffle’ isolated in red box

• Annotated ‘Baffle’