Inka Hydraulic Engineering at the Tipon Royal Compound (Peru)

The Inka site of Tipon had many unique hydraulic engineering features that have modern hydraulic theory counterparts. For example, the Tipon channel system providing water to the Principal Fountain had a channel contraction inducing critical flow as determined by CFD analysis- this feature designed to induce flow stability and preserve the aesthetic display of the downstream Waterfall. The Main Aqueduct channel sourced by the Pukara River had a given flow rate to limit channel overbank spillage induced by a hydraulic jump at the steep-mild slope transition channel location as determined by use of modern CFD methods- this flow rate corresponds to the duplication of the actual flow rate used in the modern restoration using flow blockage plates placed in the channel to limit over-bank spillage. Additional hydraulic features governing the water supply to agricultural terraces for specialty crops constitute further sophisticated water management control systems discussed in detail in the text.

Post-war reconstruction (c. AD 61–70)

London was rebuilt after the Boudican revolt, chiefly in the period AD 62–4. Military engineers set a new fort over the ashes of the city destroyed by British rebels, rebuilt the harbour with massive new quays, introduced new hydraulic engineering to supply London’s bathhouses, and established new roads and causeways to speed the movement of people and goods. The presence of detachments of auxiliary soldiers used to garrison the city after the revolt is witnessed by exchanges recorded in wooden writing tablets, and by finds of military and cavalry equipment. High status cemeteries included the tomb of the procurator Julius Classicianus, an exceptional group of exotic cinerary urns including one carved from Egyptian porphyry, and the inhumation of a woman dressed in a way that might identify her as a member of the pre-Roman aristocracy. Irregular and fragmented burials are also described, and it is suggested that these may witness practices of corpse abuse and necrophobic ritual. The mutilated corpses of those denied normal burial may have been dispatched to the underworld by disposal in water, and disturbed corpses besides London Bridge may include the victims of Roman retributive violence following the Boudican revolt.

Episodes of renewal (c. AD 90–110)

The pace of urban growth in London appears to have slowed in the period immediately after Agricola’s governorship. At the end of the first century, however, London’s port saw extensive repair and enlargement. Harbour improvements commenced c. AD 94–8, perhaps under Nerva’s administration. It is argued that these works were part of a wider programme of support for the annona, designed to secure the army’s support for the new political regime. These harbour works were resumed under Trajan, when improvements were also made to the hydraulic engineering represented by wells and water-lifting devices. Several baths were built or improved at around this time, some of which may have been attached to temple precincts near the borders of the settlement.