Q: When and how did the Department/Minister and NBN Co justify aerial construction in the first place?

A: Back in June 2009, a departmental Discussion Paper “National Broadband Network: Regulatory Reform for 21st Century Broadband” foreshadowed that at least some of the proposed NBN should employ aerial construction to reduce roll-out costs and raised the prospect of amending relevant legislation to facilitate this. In March the following year, NBN Co declared: “if power is underground, our fibre is underground… If there is an aerial power distribution, we may have an aerial local fibre distribution. We will evaluate those on an individual, module-by-module basis.”

Then on 10 August 2011 the Minister for Broadband, Communications and the Digital Economy released proposed amendments to the Telecommunications (Low-Impact Facilities) Determination 1997 and the Telecommunications Regulations 2001 for public comment. The proposed amendments include granting NBN Co the power to deploy aerial/overhead cabling without having to obtain state, territory or local government planning permission.

Q: Does the NBN constitute ‘nation-building infrastructure of the future’?

A: Yes and no. As a telecommunications-carrying medium, optical fibre is unsurpassed in its ability to carry ever-increasing amounts of data as technical standards and interfaces are upgraded. In that respect, it is often regarded as being ‘future proof’. However, attaching optical fibre cabling to electricity or utility poles - infrastructure of an earlier century – is a highly retrograde step. It’s akin to building a house on beach sand, in full knowledge that the next storm will wash or blow it away!

Q: Won’t a fully underground NBN be more costly and slower to roll out than one involving aerial construction?

A: It is beyond question that, compared to underground deployment, aerial construction of the NBN will be both faster and less expensive. The March 2010 McKinsey-KPMG Implementation Study, commissioned by the Government, estimated that the cost of underground trenching in a new trench, depending on the trenching technique used, could range from $60 to $150 per metre compared to aerial installation costed from $20 to $30 per metre. As part of a submission to an ACCC review of pricing principles, Optus considered that aerial deployments can be built four times faster than networks requiring underground cabling and that the NBN could be built for as little as $18 billion if 100 per cent aerial construction was used, $33 billion if the extent was 70 per cent and as much as $60 billion with all cabling underground.

The final word on the impact of aerial construction must come from the NBN Co Corporate Plan summary revealed December 2009, though the full plan details are not made public. The Corporate Plan assumes that 25 per cent of premises will be passed aerially in the Local network, representing 31,000km of aerial deployment. Furthermore, the Plan reveals that if instead aerial deployment was constrained for example because of limited access to the aerial corridors, which can be estimated by limiting aerial to 10 per cent of Brownfields premises in the local network, then NBN projected returns would reduce from 7.0 per cent to 6.8 per cent and total/peak funding would increase by $1.8 billion (with government equity increasing by $1.3 billion). This amount compares with a total estimated funding requirement of $40.9 billion.

In summary then, the NBN Co Corporate Plan reveals the total funding requirement to be:

  • $40.9 billion, with 75 per cent undergrounded
  • $42.7 billion, with 90 per cent undergrounded

The cost of a 100 per cent undergrounded NBN local network is not revealed in the Corporate Plan.

Q: What are the adverse consequences of aerial construction?

A: (i) All aerial cables (and electricity lines) naturally sag in a catenary fashion such that the lowest point occurs mid-span. Road traffic regulations require that this mid-span clearance of the lowest cable above the crown of the road must be no less than about 5 metres. Where this clearance is inadequate, high road vehicles are likely to snag the cable - resulting in broken cables, broken lines and interruption to electricity and communication services.

Maintaining the necessary minimum clearance becomes more difficult when the road slopes longitudinally or laterally (i.e. one side is higher than the other) and when, over time, poles bend due to their age and soil movement. At road junctions the clearance problem may be further exacerbated due to the extra number of cables converging at one location and allowance for street lights, stay wires, etc. Lead-ins to homes present a clearance problem for extra aerial cables, particularly when they pass over driveways (including those of neighbouring properties) and more so when the house is on the low side of a road and the electricity poles are on the opposite and higher side. High vehicles such as Council garbage trucks and furniture removal vans accessing properties are more likely to collect the lowest hanging cable.

All state road traffic and safety authorities are well aware of the regular occurrence of electricity poles being hit by vehicles, with electricity lines being brought down or even the poles being destroyed.

(ii) Severe storms regularly bring down trees on top of electricity lines and any telecommunications cables – particularly in rural areas and in the more tropical parts of Australia. Due to the known occurrence of damaging cyclones, the Townsville City Council’s strong preference was that the NBN be deployed underground – yet NBN Co has appointed the local electricity distributor, the direct beneficiary of pole attachment fees, as the contractor for the fibre roll-out there.

(iii) Recent Victorian and New South Wales bush fires dramatically illustrated the vulnerability of all above-ground infrastructure, whether electricity or telecommunications, and conversely the protection offered by below-ground infrastructure which escaped destruction. The compound failure of aerial electricity, telephone and Internet services totally isolates affected residents; within a day or so even mobile phone batteries are exhausted.

If access cabling for the NBN is installed aerially along local roads, it will cause old electricity poles to be unnecessarily upgraded, worsen the visual environment, reduce the clearance above road and driveway levels, and totally negate any remaining opportunity to retrospectively underground aerial cables and lines throughout Australia. Furthermore, every length of NBN aerial cabling shared by a number of customers may result in reduced service reliability for those customers due to the increased likelihood of an upstream cable being damaged by high vehicles, falling trees, bush fires or the supporting poles being hit by errant vehicles. Such causes of service unreliability remain regardless of whether the optical fibre cable deployed with the NBN has a slightly smaller diameter than that of the previous installed HFC networks.

This prognosis applies where any NBN aerial cabling is the first non-electricity asset to be pole-attached and is even more applicable where one or two HFC pay television cables already exist. Not only will NBN access cabling suffer degraded service reliability in its own right once aerially constructed, no broadband service is possible without reliable electricity to customer premises. With both NBN and electricity services supported on the same pole route, the incidence of outages having adverse lifeline consequences is further magnified.

Q: Since optical fibre cable is non-metallic, won’t it be installed amongst existing electricity wires and hence be inconspicuous?

A: In theory, optical fibre cabling could be safely installed immediately alongside electricity wires attached to pole cross arms and thereby become less visible and more protected from external interference. However, it appears that practical considerations related to installation and maintenance, let alone the standard of training required by personnel, result in an entirely different outcome. Casual observation indicates that even electricity distribution companies intentionally install their own optical fibre cabling separate from the electricity lines; where electricity company fibre cabling has been installed atop poles it appears to be of a long-distance nature between sub-stations and is not accessed on a pole-by-pole basis for local distribution. The very first NBN roll-out in Scottsdale, Tasmania was deployed aerially since early 2010. Clearly, on that occasion Aurora Energy reckoned that technical and service delivery standards of its electricity distribution operations would be adversely affected if the fibre-to-the-home network were to be installed more closely to the electricity assets – regardless of the fact that such a modern day network is non-metallic. After all, the NBN network is foreign to the business of the electricity distributor. Visual inspection suggests that a separation of one to one-and-a half metres (the ‘LV exclusion zone’) has been stipulated for the safety of personnel involved and/or to ensure minimal impact on electricity service reliability. Nothing has changed with subsequent NBN aerial roll-outs elsewhere in Australia.

Q: Who is most likely to be disadvantaged by NBN aerial construction?

A: This is a most appropriate question to ask since the NBN Co Corporate Plan states that 25 per cent of the local access network roll-out will be aerial. NBN Co has clearly stated (and it would be gross stupidity otherwise) that they will not be creating new utility poles where none exist. So for starters we can rule out NBN aerial cabling where existing electricity lines are underground. Not surprisingly, Telstra’s cables are universally underground where electricity lines are underground. Electricity (and hence also telecommunications) lines are typically underground in most new residential and many new industrial developments throughout Australia since about 1985, though no doubt there are instances where this didn’t happen in a few areas due to local circumstances. Electricity lines are also underground in many CBD and near-CBD areas, certain areas of historical significance and where deemed necessary for operational reasons.

It is understood that NBN Co strongly prefer their main route optical fibre cabling in built-up areas to be underground so as to gain maximum protection from mechanical interference. NBN Co has at times stated that NBN cabling may be constructed aerially wherever existing Telstra lines are aerial – an argument which is not only flawed but a practice that seems not to have been followed so far. However what is now abundantly obvious is that the 25 per cent of streets to be ‘blessed’ with aerial construction will disproportionately occur where property frontages are larger than usual, where Telstra’s pipe network is of smaller diameter and where the terrain is rockier than usual. Most of these occurrences happen to arise on urban fringes - which just also happen to be more exposed to damage from bushfires and/or storm-driven debris, not to mention being more poorly served by emergency and health services.

Q: If the NBN is fully undergrounded, where will the extra money come from?

A: As the original project was mooted to cost some $43 billion but is now scoped at a total of $40.9 billion (for a 75 per cent undergrounded NBN local network), the estimated extra cost of $1.8 billion for a 90 per cent undergrounded NBN local network falls within the residual envelope, i.e. the total project cost becomes $42.7 billion. Expressed in more pedestrian terms, the impact of an additional $1.8 billion amounts to a once-off sum of about $59 per person - or perhaps 17 cappuccinos in the lifetime of each person.

Q: Aren’t the dimensions of the cable for fibre and for the hybrid fibre co-ax somewhat different... so it is really not exactly the same?

A: Referring to the Media item, ABC Lateline of 10 March 2011, the then NBN Co Chief executive Mike Quigley claimed that:
  • “the dimensions of the cable for fibre and for the hybrid fibre co-ax that people remember are somewhat different”
  • “We also don't have with fibre the amplifiers that sit up there between or on the cables. So it is really not exactly the same.”
This is a furphy. To all intents and purposes, the diameter of NBN optical fibre and Pay TV coaxial cables are much the same. Whilst amplifiers will be absent, loops of fibre cable and junction boxes will still be evident on electricity poles.