Detailed design and equipment specification for the installation of two 15 / 23 MVA (dual rated ONAN / ONAF) 33 / 11 kV power transformers to replace smaller transformers at several 33 / 11 kV zone substations and an upgrade of the transformer protection and tap changer control. Detailed design services included specification and tendering services for low noise power transformers, foundation civil design, earth grid computer modelling and design, calculation of new protection and tap changer control relay settings, specification of power cables and detailed design of new equipment layout, electrical connections (including local control, auxiliary power and SCADA controls and indications) and oil containment facilities.