PUBLIC LIGHTING & NATURAL GAS
By A.E. Minty BE, FIE Aust. FCIT
After twenty years on major dams, wartime flying and hydro- electric work, Bill Minty joined NCDC in 1959 as the Project Engineer for the planning, design and construction of Lake Burley Griffin. He was subsequently appointed a Director with responsibilities for a wide range of hydraulic, transportation and other major projects (including public lighting and natural gas). He retired in 1981 after nearly twenty-three years with NCDC. As well as being a past chairman of Canberra Division of The Institution of Engineers, Australia, and a Councillor from 1979 to 1981, he has been a member of the National Panel on Engineering Heritage since its inauguration in 1979.
CANBERRA’S standard of public lighting is one feature that has distinguished the National Capital from other cities. From its inception, electricity was reticulated to houses using timber poles placed along the back fences to carry overhead conductors, thus removing from the streetscape the main elements that disfigure Australian cities.
The primary penalty for this hiding of poles and wires, is the need for a separate system of street lighting, using underground cables. Until the early 1960s, a high proportion of street lighting installations used short columns 2.5 or 3.5 metres high, carrying a decorative lantern, with a vertically burning incandescent lamp of low wattage and efficacy. In some cases, where timber poles had to be erected in the street to carry high voltage lines, some street lighting was provided by a short outreach arm off the timber pole and carrying the old ubiquitous radial wave reflector and incandescent lamp.
Until the early 1960s, all this public lighting was pedestrian lighting, with the outreach arms on the timber poles directed towards the house and footpath rather than the road.
In 1962, Kings Ave Bridge was completed with a new approach to lighting using a line of fluorescent tubes in each outer handrail. This was not an attempt to provide traffic route standard of lighting on the carriageway but the one line of tubes was used partly to light one footway and delineate the edge of the carriageway, and partly to shine on the white concrete parapet for night-time display of the bridge structure a splendid example of glare-free integral lighting. This was a decided improvement on the remote flood lighting so often developed as an afterthought when a bridge or building is complete. This lighting installation won the annual award of the Illuminating Engineering Society.
Kings Avenue bridge was so impressive in terms of the clean lines by day and fine lighting effect by night that the proposal to mount post-top lights on Commonwealth Avenue Bridge was abandoned. At the time, the design of the superstructure of Commonwealth Avenue Bridge was complete and construction of the bridge had started. Nevertheless, timber mock-ups were made in Canberra and new designs developed that would use a similar handrail lighting approach. Lines of tubes were also incorporated in the outer aluminium parapets to light the exposed aggregate panels of the bridge superstructure. This installation also won one of the annual awards of the Illuminating Engineering Society.
About 1963, three significant events occurred within about one year of each other. Firstly, the ACT Electricity Authority (ACTEA) was set up and unlike the practice in most other Australian cities, responsibility for planning, design and construction of public lighting was given to the National Capital Development Commission rather than ACTEA. Next, some parliamentarians attempting one night to walk the short distance from the Hotel Canberra to Parliament House had one of their number trip and fall down in the poorly lit street. Strong correspondence followed urging NCDC to do something about street lighting.
At about this time also, the Standards Association of Australia set up a committee (with NCDC representation) to prepare an up-to-date set of recommended practices for modern street lighting. In 1964 the section of the code dealing with traffic route lighting was published. In 1965 Northbourne Avenue was provided with Canberra’s first- ever traffic route lighting (to the new code standards) and was followed progressively in subsequent years with similar standard lighting throughout most of the urban areas.
In lieu of the old vertically burning low efficacy incandescent lamps of 100 watts each used for old pedestrian lights, 400 watt high pressure mercury vapour fluorescent lamps were used which burned horizontally in lanterns designed for fine optical control of light output to meet the new SAA code requirements. For higher mounting heights on major roads, 700 watt lamps have been used. Similarly, on the smaller distributor roads, 250 watt lamps were used.
Soon after the development of the first high mast lighting in the Cumberland Basin in England, NCDC was faced with the lighting of the cloverleaf interchanges on Kings and Commonwealth Avenues and Parkes Way. Rather than have a forest of lighting columns of the usual 10.7 metres height, it was decided to use the Cumberland Basin techniques of 4/1000 watt lamps mounted on columns 30.5 metres high. This cut the number of columns to about one third of that needed for a conventional design.
The 1960s also saw the development of the high pressure sodium lamp with its much higher efficacy in terms of lumens per watt. However, NCDC saw considerable advantage in the blue/green colour of the mercury lamps enhancing the colour of the adjacent foliage. As the cost of these new lamps was progressively reduced and assurances developed on other aspects, NCDC agreed to install some test sections for community comment. With no adverse reaction and a developing concern for energy consumption, a decision was made to adopt the light apricot colour of high pressure sodium lamps for all traffic routes. But the deeper orange of low pressure sodium continued to be rejected on colour grounds despite its very much higher efficacy.
The early post-top lighting columns in a landscaped street devoid of timber poles and wires provided a very attractive daytime appearance but as a lighting installation it was not very effective.
Following the major improvements made in traffic route lighting by changing vertically burning lamps to horizontally burning lamps, NCDC in association with ACTEA experimented with 40 to 100 watt luminaires mounted from 3.5 to 7.0 metres high. Apart from the twin twenty watt fluorescent tubes so popular in other Australian cities, the market at that time did not offer a good range of lower wattage lanterns. However, following the production of the traffic route lighting code, the SAA set up another committee to prepare recommendations on pedestrian lighting. Again NCDC was represented and indeed hosted the committee in Canberra to see the trial installations. The committee was loathe to accept any vertically burning post-top lights as a functional light, but made some provision for these in the 1971 code. After prolonged debate between the functional and economy interests of the engineers and the daytime appearance interests of the architects NCDC accepted the twin twenty watt fluorescent tubes on a slim column for collector roads i.e. roads intermediate between the minor residential streets and the main distributor through a neighbourhood. The latter and higher standard roads would use traffic route standard lighting.
In the early 1970s, the observatory at Mt Stromlo approached NCDC about the problem they had with the increasing brightness of the night sky aureole due to the rapidly increasing number of street lights particularly those close to and south of Mt Stromlo, where the observatory people were trying to measure extremely faint stars. A similar problem had been encountered at the American Observatory at Kitt Peak and had been helped appreciably by shielding and other changes to the public lighting.
NCDC suggested a change also to the linear sodium source, but at the time the observatory did not see this as useful. NCDC therefore engaged the University of NSW to solve the problem. A filter was developed to screen out offending wavelengths, but it was an unattractive colour. The observatory then found a way of coping if NCDC changed to sodium. This coincided with the availability of very low wattage (18 watt) sodium low pressure lamps. Hence a programme commenced for installation of these throughout the district of Weston Creek.
The final section of the Canberra public lighting story covers the floodlighting of buildings and special features, particularly those in the Parliamentary Triangle.
Any record of public lighting in the Central Areas of Canberra has to start with the late Richard Gray, an architect partner of the London based consultants of William Holford and Partners.
Following his architectural advice on Kings and Commonwealth Avenue bridges, Richard Gray, responding to a Brief from NCDC, presented a three-volume report1 in which he said:
“Because of its balanced layout and the symmetrical grouping of buildings around the lake, Canberra can, without affectation, adopt a classical formula for its lighting scheme. (that will be) original and unique”.
The concept he presented for the Central Areas of Canberra between Capital Hill and the Australian War Memorial would provide by night a civic design composition equivalent to the civic design by day.
This design was based on a framework of main avenue lighting using semi cut-off lanterns for Commonwealth and Kings Avenue and special lanterns along Anzac Parade. Within this framework, footpath and carpark lighting was to provide the background patterns; and the illumination of bridges, buildings, fountains and trees were to be the enriching ornaments. High mast lighting would punctuate the avenue intersections, and provision would be made for temporary gala lighting to mark national and festive occasions.
All the lighting was to be designed to be seen in the round and to provide freedom of movement by pedestrians around the central area parklands by night.
This called for integral or short offset floodlights. Unfortunately there was a tendency for an architect to install strong floodlights well offset from the building and try to show off his building to the best advantage only from a distance. Thus people walking around or emerging from a building by night would find themselves facing a battery of glaring floodlights. The brightness of a building depended more on such issues than on the freedom of movement, and harmony and cohesiveness of the total night-time concept of Richard Gray.
In an attempt to come back to Richard Gray’s concept and give the Provisional Parliament House its rightful place in the Triangle, the engineers of NCDC themselves designed the augmentation of the floodlighting of that building, lifting its brightness above all others in the Triangle yet using short offset and integral methods allowing Parliamentarians unfettered use and egress from the house by night.
One of the main features of Richard Gray’s concept for the lighting of the Central Area, was the ceremonial treatment of Anzac Parade with flanking rows of soldier- like columns carrying ellipsoidal luminaires the full length of the Parade from the floodlit War Memorial to the intersection with Parkes Way.A very attractive column design was evolved by the consultants on this project but NCDC asked them to add a further 1.5 metres to the height. This was readily agreed. From the architects point of view, the preferred luminaire would have been the white translucent ellipsoid throughout. From the engineers viewpoint, Anzac Parade was a major traffic route for which a translucent bowl of any shape would be hopelessly inadequate optically. Hence the design evolved provided the clear acrylic bowl in the bottom through which optically controlled traffic route lighting is projected, but the bulk of the luminaire is the white translucent ellipsoid which provides the ceremonial parade character to the lighting as viewed by day and by night.
As this book goes to press, no attempt has been made to cover the lighting of the National Gallery or High Court. The floodlighting of the new Parliament House will hopefully have regard for the night-time civic design of the Parliamentary Triangle and will allow free movement of people by night inside and outside the building without being blinded by remote floodlights. Finesse rather than brute strength should be the philosophy. For instance, under careful NCDC control, the historic Blundells Cottage was “moonlit” rather than “floodlit”. It is hoped that more use will be made of integral lighting such as Kings Avenue Bridge, Commonwealth Avenue Bridge, the Law Courts, the Mint, the MLC Building and others.
Whilst NCDC generally used private consultants for the special lighting such as Bruce Stadium and high mast work, the detailed design and construction of normal street lighting was done for NCDC by the ACT Electricity Authority.
Indeed the writer would pay a strong tribute to the two successive Chairmen of ACTEA, Mr H.A. Jones and Mr W.E. Bolton, and their various engineers for the assistance they gave on all lighting work and the close harmony of the partnership between the two organisations.
The record of engineers’ initiatives and actions in Canberra would not be complete without a brief reference to Natural Gas.
Two early studies on the possible introduction of natural gas failed to persuade authorities to bring it to Canberra. In 1980 however, the engineers appreciated that continuing increases in oil prices, large increases expected for electricity charges and the error in principle of burning a finite resource like oil, made plain the advantages of Natural Gas for the heavy space heating and similar needs of Canberra.
A further economic study was mounted in association with other Canberra organisations, Department of Capital Territory, the Pipeline Authority, Department of Housing and Construction and ACTEA. Cabinet submissions were prepared and after inviting proposals from interested organisations, the choice fell between the Australian Gas Light Company and ACTEA with the former being chosen.
The NCDC initiated feasibility studies early in 1980 to identify which government-owned buildings were eligible for conversion based on economic benefits of gas over oil fuel. Where a clear advantage in changing to natural gas was demonstrated, design and documentation work for such buildings was undertaken.
On 24 July 1980, at King Edward Terrace, opposite Parliament House, the Prime Minister, the Right Hon. Malcolm Fraser, turned the first sod in the construction process for Natural Gas for Canberra.
After tapping into the Moomba (SA) to Sydney gas line at Gunning, construction work proceeded on the Gunning to Canberra spur line and on the trunk mains from the City Gate at Mitchell on the northern edge of the city, to the Woden Town Centre in the south, to the Belconnen Town Centre in the west and to Fyshwick in the south-east.
By the end of 1981, NCDC had converted 39 government buildings to natural gas, and on 18 February 1982, the Prime Minister formally opened the valve to allow Canberra’s first gas to flow.
In the first year these 39 buildings reduced the consumption of fuel oil by some 23,000,000 litres representing a saving of $2,300,000 at current fuel costs. These buildings were the first of 185 government buildings for which such savings are expected and for which contracts had been let by NCDC in a planned programme to convert offices, hospitals, institutions and schools from fuel oil to natural gas. By the end of 1982, a further 105 government facilities had been connected with another 60 expected in 1983.
Parallel with this work, the Australian Gas Light Company proceeded with the detailed design and installation of its domestic reticulation, based on householders responses to conversion proposals. By the end of 1982, 1,000 houses had been connected, allowing these householders to appreciate the savings in the cost of space heating during the long cold Canberra winters.