40 minute walk to site with great views and underground tunnels.
At Northern Junction, go through the farm gate to the left of the interpretative panel, the gun battery is in front of you.
The picture on the interpretative panel shows the Battery Commander watching the last test firing of the guns in 1957, which was taken just outside the Battery Observation Post.
To the north west, or left hand side of the track, across the paddock is the Engine and Radar room, disguised as a farming shed during World War II.
To the south east, or right hand side of the track, across the paddock, is a collection of structures forming the Battery Observation Post (BOP) complex.
Battery Observation Post (BOP) complex and Radar Room (Radio room obscured)
These structures include :
- Battery Observation Post (grass covered turf on roof)
- Radar Room and Radio Room (adjoining)
- Wireless Room (above ground)
- Emu Observation Post
- associated Engine Rooms.
Above Ground Wireless Room
The first structure you see is the Above Ground Wireless Room built in 1937.
The bulk of the building is constructed below ground with only 750mm standing above ground.
The building can be accessed from either end by a set of stairs.
The 'room' consists of three rooms (1 large and 2 small).
There is a good view to Mullet Bay.
The plantings on the slope to the left of the beach were carried out by the Downtown Rotary Club.
The planted Pohutukawa on the right hand slope were part of the Project Crimson project and were planted in 1994/95.
Battery Observation Post (BOP)- Radio Room - Radar Room
Also completed in 1937 and partly recessed into the ground, the Battery Observation Post provides a 220 degree field of view.
The radar room was built adjacent to the BOP and to the rear is a radio room.
The area between these three spaces was in filled to provide an access lobby.
The doors were made of steel plate with steel windows and shutters.
The BOP housed all the range finding equipment.
There are plinths used for mounting equipment upon.
There is also a network of open channel floor drains, and piped services can still be seen extending from the radio room to the radar room.
The radio room (the smallest room) features the remains of radio switching gear mounted on the west wall.
There are depressions in the ground nearby (slightly downhill from the structures heading east).
They were earth dugouts (shrapnel pits) with timber roofs overlaid with turf built for the safety of personnel.
There is an excellent view to the gun emplacements.
Emu Observation Post (EOP)
This was the naval anti submarine observation post manned by Navy personnel. It was used in the detection of enemy ships and submarines by monitoring the indicator loops and ASDIC arrays laid underwater out in the Gulf.
Its other role was observation of the contact minefield.
Again partly recessed into the ground and accessed by a set of stairs. It had its own power supply, fuel store and rest room. It is subdivided into a number of rooms to allow the operation of all the various equipment.
It is difficult to see this structure from the track to the emplacements; the EOP is located downhill from the two farm water tanks.
Both the EOP and the BOP had there own engine rooms where power was generated.
Their interiors are divided into two rooms - the larger is the generator room, the second is the fuel store.
The Emu engine room is partly recessed into the ground and accessed by a set of stairs; there where diesel generators, with armoured cables in shallow trenches taking the electricity to where it was needed.
Go and explore, take A Torch to Enter Underground Buildings.
Click on the links below to learn more about the guns and defence structures of Motutapu:
Gun Emplacements of Motutapu
Heritage areas of Motutapu
Motutapu Archaeological & Historic Landscapes Heritage Assessment Document