Question: Which engineering firm monitored Stage I construction of the Sydney Opera House?
About the article "Sydney Opera House", section "Stage I: Podium".

Candidate passages:
Stage I commenced on 2 March 1959 with the construction firm Civil & Civic, monitored by the engineers Ove Arup and Partners.
The government had pushed for work to begin early, fearing that funding, or public opinion, might turn against them.
However, Utzon had still not completed the final designs.
Major structural issues still remained unresolved.
By 23 January 1961, work was running 47 weeks behind, mainly because of unexpected difficulties (inclement weather, unexpected difficulty diverting stormwater, construction beginning before proper construction drawings had been prepared, changes of original contract documents).
Work on the podium was finally completed in February 1963.
The forced early start led to significant later problems, not least of which was the fact that the podium columns were not strong enough to support the roof structure, and had to be re-built.
The Fort Macquarie Tram Depot, occupying the site at the time of these plans, was demolished in 1958 and construction began in March 1959.
It was built in three stages: stage I (1959–1963) consisted of building the upper podium; stage II (1963–1967) the construction of the outer shells; stage III (1967–1973) interior design and construction. 
 and The Sydney Opera House.
Steensen and Varming were chosen by the Danish architect Jørn Utzon as the mechanical consulting engineers for the new Opera House project in Sydney in 1957.
The Australian branch of Steensen & Varming Australia (later to be known as Steensen Varming) was led by Vagn Prestmark a partner from the Danish Steensen & Varming firm.
Prestmark established Steensen Varming in Australia in 1957 and the company was permanently established in Australia in 1973.
Steensen & Varming was not well known in Australia prior to the Sydney Opera House, it was however well established in Europe with offices in Dublin, Belfast, London, Edinburgh and Copenhagen and employed over 500 people by 1973.
When Utzon resigned from the Sydney Opera House in 1966, Steensen & Varming continued as the mechanical consultants ultimately delivering the design, documentation, contract administration and detailed site supervision of all mechanical, hydraulic and fire protection services, including the controls/supervisory system.
Steensen Varming's most known contribution to the Sydney Opera House, was the design for the water heat pump system.
The architects and engineers agreed that constructing a boiler chimney stack or a cooling tower, would not be in keeping with the design of the Opera House, which ruled out the two normal approaches for large-scale air conditioning.
Steensen Varming provided the design solution in using a heat pump system, which used water from the harbour as the cooling agent: a truly elegant and efficient solution, even by today’s standards.
There were three main considerations which led to the design of the Opera House air conditioning as a heat pump system, the availability of the waters of Sydney harbour as a heat sources and sink, the aesthetics and the savings that could be achieved with a water-to-water heat pump.
Three pumps draw water from Circular Quay, the water is filtered to remove debris and then passes through tubes and is discharged into the harbour at the opposite side of the Opera House.
Fresh water circulates between the heat exchanger shells and the shells of the condesner and evaporators of three centrifugal chillers / heat pump sets.
The design innovation and technical expertise demonstrated in this unique landmark project subsequently led to the awarding of other projects in Australia to the Steensen Varming practice.
The engineering construction of the Sydney Opera House was featured in a National Geographic/BBC production hosted Richard Hammond called Engineering Connections.
The programme aired in Australia on 13 March 2010.
Part of the documentary featured the seawater heat rejection system originally designed by Steensen Varming and assistance on this documentary was provided by Steensen Varming who acted as technical liaison to the production team. 
  RAIA Merit Award, 1974.
Meritorious Lighting Award of the Illuminating Engineering Society of Australia, 1974.
RAIA Civic Design Award, 1980.
RAIA Commemorative Award, Jørn Utzon - Sydney Opera House, 1992.  
It is best known for its design work for the built environment.
Projects to which it has contributed include the Sydney Opera House, which is largely credited with launching Arup into the premier league of engineering consultancies.
The BBC and RIBA documentary "The Brits who Built the Modern World" highlighted Arup’s collaboration with architects and described Arup as "the engineering firm which and his peers [(Lord Richard Rogers, Sir Nicholas Grimshaw, Sir Michael Hopkins and Sir Terry Farrell)] most frequently relied upon."