Ngā Tohuwhenua Mai Te Rangi: A New Zealand Archeology in Aerial Photographs
European fortifications tend to follow a regular pattern which can be more or less complex depending on the size of the force, the extent and complexity of the tactical and strategic situation, and the time available to make the fortification. The field situation of any particular fortification is complex, and many combinations of defensive feature and tactical compromise were needed in practice. The key point is that fortifications were designed to offer a good field of fire to the defending forces, while at the same time protecting them from the fire of the attacking force. The typical European fortification of the period was the redoubt. This was a square or rectangle of ditch and bank forming a defended perimeter. The ditch was external to the bank. From the base of the ditch to the top of the bank was as much as 6 m. The defenders stood behind the bank to fire, not in the ditch. The ditch was designed solely to prevent a rush of attackers into the fortification. In opposite corners, 'flanking angles' were built. These were an extension of the corner built out into the line of the perimeter ditch and bank. From it defenders could safely fire into any attackers who might have gathered in the ditch. Any single redoubt needed only two flanking angles, on opposite corners, because they were designed to cover the fire along the two trenches at right angles to each other.
The angles were designed to be out in the line of the trench, so that defenders could fire into the attacking forces gathered in the perimeter trenches for a final assault. An example of the use of flanking angles is Thacker's redoubt built in 1865 in south Taranaki. If a redoubt was more than about 40 m square, flanking angles were not recommended. In these cases, bastions were formed at intervals along the wall. These were projections through and forward of the line of the trench, serving a similar function to the flanking angle, and were not uncommon in the larger Māori entrenchments also. 5
Blockhouses were sometimes built by British or Colonial forces. These were fortified houses constructed of solid timbers or with double walls filled with gravel. The defenders would fire out through loopholes. Blockhouses were sometimes built at the 'flanking angle' of a redoubt, i.e., they were the flanking defence, with two rare examples surviving in the Manaia Redoubt, Taranaki. Stockades were another form of fortification that may be associated with defensive ditches and banks. A stockade consisted of heavy squared timbers placed adjacent to each other in a trench. The trench was backfilled forming a solid timber barrier, again with holes for the defenders to fire through.
Such formal fortifications were not lived in permanently. They were too small. If they were in a forward position away from existing settlements, the defenders typically lived in small huts dug into an adjacent hillside. In the phases of 'pacification' from the late 1860s, semi-permanent fortifications were built in tactically useful positions where there was good farmland. Former soldiers were allocated this land on the understanding that they would stay to defend it in the local fortification if need arose. Such practice was followed in Auckland, Waikato, Bay of Plenty and Taranaki, although the farmland could not be properly used at first because of the poor transport routes to the remote towns. 6
A comment should be made about the European's offensive use of earthworks. The digging of trenches towards defended positions—saps—was not an innovation in New Zealand but established European military practice. Saps had of course been in use many centuries earlier in the European theatres and were an established form of siegecraft, but the techniques were re-learnt in the dawning of the era of accurate and massed rifle fire. 7page break
Thacker's and Inman's Redoubts, built during Cameron's South Taranaki campaigns of 1865-66
Inman's Redoubt [above] lies on the north side of the Manawapou River, Thacker's [below] on the south. Each site is about 45 m across. The rectangular defensive perimeters have flanking angles at opposing corners. At the head of the scarps of the natural terraces are hut sites, linked by a formerly roofed trench to the fortification. Near Thacker's redoubt other possible hut sites show on the flat as slight rectangles of raised bank. On the far right is a small circular ditch, about 6 m across. This is a potato clamp, probably associated with the period the fortification was occupied. The double trench running up the photograph is a hedged double ditch and bank fence, cutting into and hence postdating the fortification. An early road runs across the photograph.
It served the obvious purpose of protecting attacking forces from concentrated fire from the defensive positions. Saps also commonly had returns built along their length, because the line of the sap was inevitably oriented towards the defensive position and subject to enfilading fire. The walls were maintained in good condition by placing fascines (bundles of sticks) against them. The front of the sap was usually protected by gabions, elaborate wickerwork or bundled manuka rollers pushed in front of the advancing face, allowing the diggers to remain semi-erect in the course of their work. In New Zealand, examples of saps still surviving are at Ngatapa, inland East Coast, where they were used against a strong defensive position of Te Kooti Arikirangi's, and at Pukerangiora, another strong defended position, inland on the Waitara River, Taranaki. These fortifications are illustrated in the relevant regional chapters.