There have been a few crane incidents recently, and it may be years if ever, before the public details of these are available. Trying to get to the bottom of these incidents, one is faced with process obfuscation, uncertainty and opacity.
Politicians use the sight of hundreds of cranes on the skyline as the embodiment of good economic times and the success of their policy levers. They are fair weather sailors who displace crane intrusiveness and the operational risks involved with the eroticism of seeing a new crane erected.
Contractors are quick to make a crane or multiple crane selection based the ease of just ordering up another, and adding it to the tab. Few consider just how cranes intrude into the public realm or the possible implications of those intrusions.
Crane intrusion into public spaces occurs in many ways. Some of these include:
- when cranes are erected or dismantled from, or over the public way
- whenever a load is lifted from outside of a vertical building boundary line
- when overhead protection (hoardings) above footpaths occurs
- while construction zones are in place denying other uses
- when the hours of work extend beyond normal times and crane noise continues
- when traffic is halted while deliveries or removal of materials from sites occur
- whenever cranes lift loads over a public space and lollipop people halt passage
- whenever a crane accident has occurred and the public realm is disrupted
Often these intrusions into the public realm may last for several years. Contractors assume it is their reasonable right to simply apply for and be granted the necessary permits to undertake these intrusions. The relevant consent authorities typically grant such applications, as to do otherwise would stand in the way of progress. Members of the public often have little or no say in challenging these consents or in seeking more details or balance. This conversation is not about the need for cranes infringing the public realm, but it is about the reasonable quid pro quo for the concessions granted.
After a crane incident on a University of Technology Sydney construction site in 2013, the story relayed was that the incident had resulted from a leaking hydraulic line that controlled the crane’s luffing (raising and lowering the jib) system. It then dripped on to a hot manifold below and catching fire. The result was that the jib collapsed.
The surrounding streets were thrown into chaos, the crane damaged the formwork system and work stopped on site for some days. The crane and a substantial part of the damaged formwork system needed to be replaced. Thankfully nobody was injured, but the CFMEU made a big deal of it.
In response to numerous enquiries to WorkCover, apart from the names of the parties involved, there was no other publicly available information. It was reported that the situation regarding the hydraulic lines in older, similar cranes was then investigated and changes made. I was unofficially told that it was unlikely that a detailed report would be made available because of the complexities of pursuing any formal proceedings in matters like these. Notwithstanding, I lodged a formal request for this information via the Government Information Public Access Act in May 2014 (ref: GIPA 2014/007030). The response was:
"You asked to know how long it would be until the investigation file for the UTS crane incident can be made available. As advised in the access decision to you dated 8 May 2014, the matter is still active and unfortunately it’s not possible to estimate when the file will be available. WorkCover is currently reviewing the findings of the investigation and considering whether a prosecution should be commenced. If the decision is made to prosecute, the records will not be available until Court proceedings are finalised."
I visited the crane maker to make my own enquires and was advised that no specific details of this incident could be discussed, but I was invited to visit the factory and ask questions about the modern trends in crane design, manufacture and operation. I was advised that initially crane design was all about their physics and, as their lifting capacity increased over the last 20 years, more efficient designs had been developed.
Cranes have indeed changed over the years. Favco 250 cranes (lift capacity 2.5 tonnes at a 33-metre radius), so common not too long ago, gave way to newer models: 350s, 450s, 750s and 1500s. Each opened up more construction method opportunities while industry custom and practice around these cranes then became the global benchmark. Crane lifting capacity these days can surpass 200 tonnes, with many of the cranes on construction sites now using cranes with 20-tonne, 30-tonne and 40-tonne lifting capacity. Trends that have defined crane progress in recent years and will likely continue to do so include:
- the technical challenges of taller buildings and the increased length of crane ropes
- aprogressive shift away from diesel powered cranes to quieter electric alternates
- robotics, remote fleet diagnostics and in-cabin hologram driver support technology
- improving recovery-crane technology, especially winch drum brake lowering ability
Cranes are now regularly enabling projects in excess of 150 metres in height. Since 2000, there have been more than 3,000 buildings over 150 metres tall constructed worldwide. As projects press 80-plus storeys, crane ropes alone can weigh as much as three to five tonnes. These require specialist cable manufacture which can assure that ropes more than 50 millimetres in diameter roll predictably on and off the winch drum for the duration of a project. They also require new winch drum technology.
So what is the most common crane feature sought by contractors? The answer, unsurprisingly, is the speed of the hook and lifting cycle times.
The densification of cities now means permanent and growing resident populations. As a result, modern cranes are now adopting electric motors for quieter operation. Other benefits go with electric crane technology versus diesel cranes. There are more electronic diagnostic opportunities that can monitor the condition and performance of cranes.
These abilities lead to innovations in real-time servicing and lifting management. It’s now possible to record if crane capacity is being optimised or wasted. There is not much evidence of all these features being embraced so far by many contractors - especially the larger ones.
Most contractors in years past discounted the trend toward electric cranes, but that seems to have changed with many new cranes now adopting at least this feature.
On most projects, it appears the majority of cranes are not operating for more than 60 per cent of their on-site presenc. Beyond that, they rarely lift even half their lifting capacity, they spend 50 per cent of their time lifting temporary construction equipment on and off-site, and amongst the most frequently lifted items is construction waste. Not very optimal.
An exception is Hickory Builders in Melbourne, who have adopted an integrated structure and facade system that allows them to lift whole building floors using up to 20-tonne elements with a capability of two to three floors per week. Hickory use electric cranes, and as it turns out lift their heavy loads in the early evening, quietly, reducing impact on busy commercial hours traffic and pedestrian flows, and using their cranes in normal hours to pre-load floors with prefabricated utility pods, mechanical equipment and finishing materials.
Most importantly Hickory’s integrated façade system avoids the use of temporary external safety systems, immediately creating safe, less intrusive enclosed work areas at the construction edge.
Their buildings are not exposed to the usual weather disruptions of slower moving competitors, and they are already reducing overall construction times by up to 40 per cent. Quiet, optimal lifting capacity makes the speed of rope question look obsolete and dull. Hickory are about optimising crane-time and productivity.
Crane technology and capability is extremely well engineered and safe. Cranes are made in factories and their design and supplier value chain is tightly managed. It’s what happens after that should attract more attention.
Very few contractors are challenged by clients, their consultants or those who issue unchallenged consents for cranes to occupy the public realm for more time than is absolutely necessary. And there is evidence that the statutory agencies that regulate construction should be putting more effort into understanding the emerging crane characteristics and management options than they appear to be.
Contractors and technical training colleges should also be re-imagining crane-related jobs and the more sophisticated capabilities that managers and operators should be acquiring. It is possible that some of the recent crane incidents may have been minimised if remote crane diagnostics and fleet management were in place. There will always be human error and external factors (i.e. wind) that may challenge the physical limits of cranes.
But the traditional crane attendant function needs to be transformed into a more highly qualified ‘load master’ profession that helps manage crane selections, load planning and utilisation. It is these ‘load masters’ backed up by off-site support logistics that should be responsible for making the case for each and every future crane intrusion into, or over the public realm.
It is, but for the grace of god that one or more of the recent crane incidents did not result in worse outcomes. As buildings get taller and loads increase, the potential risk in this space also increases if all of the available tools are not applied and overseen by modern operators.
There is no better example than that of temporary cranes used to recover the main crane at the end of projects. These recovery cranes have been amongst the recent incidents. Take for instance an incident linked to a recovery crane braking system failing on a project some years ago. A piece of a crane known as the ‘butt’ fell over 15 floors during a dismantle of a city crane on a busy weekday. The butt not only smashed its way through the overhead awning at the street, it then punched 120 centimetres into the concrete slab over the basement below. There were two minor injuries to members of the public. It served as a confronting example of what can happen.
The recent crane incidents emphasise the public need to receive prompt and transparent advisory about cause and actions taken to mitigate repeat situations, even if that advisory is qualified. Crane intrusion into the public realm should attract more consideration beyond the fleeting evening news. Construction safety and disruption is serious ongoing business.
The flip side to the positive indicators of putting up more cranes is less attention to the issues outlined here. It’s quite possible the policy makers who are around when a crane is initially erected have moved on if and when an incident happens; two or three years in politics is a long time. There is still a trailing moral responsibility to ensure that a clearer appreciation of emerging construction methods and technologies are understood and applied at project consent stage and after.
There is a duty of care to ensure that avoidable infringement into the public realm by construction is backed by constructors being made to demonstrate the bona fides of their crane utilisation optimisation plans, and by demonstration that the off-site management resources available to support crane operations (including recovery) are matched by the modern crane operation capabilities that will be needed by construction managers, crane operators and their load masters.