Turning without taglines15 November 2019
To turn and control a hanging load, taglines are used. Taglines are risky, but no alternative has seemed available. You wait years for a solution, then two turn up at once. Both are from Australia. Julian Champkin looks at the devices from down under that may turn lifting upside down.
On a high-rise construction a tower crane lifts a precast panel weighing tons. The operator works safely in his cab; the crane’s performance can be monitored, by data collected by sensors and sent over the internet to a head office that can be on the other side of the world; but the load itself is twisting in the wind and the only way to get it to the right orientation against the building is to have hefty men, stationed perhaps many storeys up, pulling on it with ropes.
It is, admittedly, what you could call a mature technology. But it is inefficient, needing much manpower; and more importantly, it is dangerous. To have men stationed halfway up a half-completed building, standing next to a two-hundred-foot drop, and expect them to manhandle a large concrete unit dangling on a rope and to manoeuvre it into a precise position to fix it in place is the stuff of health-and-safety nightmares, even if they are wearing harnesses. Looked at that way, it is surely time that manpowered rigging was replaced with something better.
Something better has in fact come along. In fact, two somethings better. One is the Roborigger, produced by a company of the same name; the other is the R-series from technology company Verton. Both companies are Australian, and both devices were developed there, which we can put down to coincidence or to sheer Australian inventiveness and determination not to let difficulties stand in the way. “There was no string of accidents to riggers that might have sparked it off,” says Brandon Hitch, CEO of the Crane Industry Council of Australia (CICA). “But Australia has always had strong labour protection laws and it has a strong independent and ‘let’s-justdo- it’ spirit. I think it may simply be that there’s a culture of not waiting for the rest of the world to solve your problems.”
Both devices rotate a suspended load to the desired position regardless of wind loads or rope torques. Both are mounted between the hook and the load. They work in similar, but not identical, ways. The basic idea is that they apply a torque, or twisting force, to the load beneath them in a way precisely calculated to put or keep the load pointing the way that it should be pointing.
We shall start with the product from the Roborigger company, based in Perth, Western Australia. Managing director Derick Markwell tells its story.
“It started out in 2015 at the Offshore Europe trade show in Aberdeen. I was talking to the CEO of a company that installs offshore wind turbines in the North Sea, and asked him if he wanted any of our lifting products. He said ‘No; but if you can give me something that will steady a turbine blade in 12 knots of wind, we would love it.’
“We had friends back in Perth who specialise in ship stabilisation using gyros. We worked with them on the problem, but we soon decided that for us gyro was not the right technology for the job. Instead, we use a flywheel, plus fan blades that are attached to it.”
The axis of the flywheel is vertical, hanging from and in line with the supporting crane rope. The hook and the load hang below the flywheel. Conservation of angular momentum sorts out the rest. “If you accelerate the flywheel anti-clockwise, then the load hung beneath it will rotate clockwise,” says Derick. “As well as that, the fan blades give a continuous torque, which we can usefully use. That is one of the things that we patented.
“Back in Perth we built a little prototype of our Roborigger and took it to Multiplex. They are the biggest construction company in Australia—they built the new Wembley Stadium—and they are headquartered in Perth. We showed them a concept, which, I must admit, was pretty average at that stage. They said ‘Make it work and there is a market for it. We would use it.’
“So we had another crack, built one that worked, and demonstrated it. Multiplex liked it and became an official development partner. They provided a crane yard, and tested it, and gave us feedback. So we had twelve months in testing mode, with feedback from users.
“Government health and safety people were enthusiastic; the trade unions were enthusiastic too. Multiplex took it on-site in December 2018 and now they are using it Australia-wide.
“We started manufacturing; we have built 18 units so far. We will have a second batch ready by the end of the year.”
The power for the flywheel and fan comes from lithium-ion batteries. “We leveraged electric vehicle technology for that, and for power management systems and motors. And we picked bits from drone technology as well. That means that our components are relatively off-the-shelf. The whole thing depends on low-cost sensors, evolved batteries, plus our patented ideas. The software I thought would be simple, but it has turned out to be really quite complex.”
It is handled by remote control. “We always have two operators, one on the top of the building, one on the bottom at street level, with a handover during the lift between them. The crane operator does not do it yet, though he could do. An Android tablet can see streaming video from cameras on the Roborigger, and data from it is visible on a normal PC.”
An early use for the Roborigger was on the new Western Australia museum building, a prestige project, which was under construction in Perth. “The builders initially intended to use it just to lift cladding panels, but they realised it is good even for small loads like a bundle of timber. It makes lowering a load into a 2.4m gap between purlins so easy. So they ended up leaving the Roborigger permanently attached to the crane and use it for everything.”
He expects it to have applications everywhere: “For tower cranes, lowering loads into difficult areas, or to place cladding panels in a wind, it is a no-brainer. It can lower a long load into a narrow space; it can lower a skip parallel to a building on a pavement so that it does not have one end sticking out into traffic. There is a huge market there.”
And the benefits are multifold: it brings, he says, savings in time and in costs as well as better safety. “There are two aspects. First, you save dollars. You never need taglines again. And that saves time. It takes ten seconds for a rigger just to attach a grabline to a load, and ten seconds to remove it. Then he has to orient the load with it, which takes more time. And there is another ten seconds letting go at the end of the lift. So if you are on a five minute cycle, shaving those seconds gives you around 8% to 10% saving in time alone.
“Loads not bumping against each other or the building means fewer incident investigations, and an incident investigation will last half a day at least during which your crane will not be operating. Construction costs of a Tier One project can run into many thousands of dollars a day, so incurring a delay when the crane shuts down is costly. Just one incident saved will pay the cost of hiring a Roborigger for a year. And the reputation damage of any accident or stoppage can be huge.” Roborigger’s business model initially is rental rather than sale. That, says Markwell, is because they are continually improving their product, and want customers to have the latest model, for both efficiency and to give feedback.
On safety, he says: “If you don’t have people standing near a load you cannot get injuries. People have been grabbing taglines for a hundred of years, and to do that you have to stand near the load. There have been an average of six fatalities or injuries a year in Australia that would not have occurred if workers had not been near the load. It is time to change that. With Roborigger the dogmen stay well to the side, not near the load or underneath it.” ‘Dogman’ is the Australian word for what Americans or British would call a rigger.
That, he says, is a culture change. “It is a big challenge for onshore users to understand. Offshore users know it already. They tend to be very much more safety-conscious than onshore. They don’t allow riggers to stand underneath any load; they don’t even allow them to touch the load. They give them big sticks to prod the load with, so they are never nearer than the length of the 1.5m prodder. Offshore tends to look at technology that will help them, and to embrace it. Onshore tends to have the attitude of ‘business as usual until you can really show us that something is better.’ The battle will be to get onshore users to do the same.”
A 20t unit has been supplied to oil and gas company Woodside and they will be using it at their LNG support sites onshore. “They are very keen to get their subcontractors to use it as well,” says Markwell.
“Multiplex have units at work in Sydney, Melbourne and Perth at the moment, and are looking at a site in Brisbane. And we have one on an extended trial with Liebherr. They asked to try it out and of course we are very happy with that. When Liebherr have finished with it there is a construction company that wants it.”
And he sees a worldwide market. “The design for Europe needs some changes, because of different rules and regulations, but we will have a demonstration unit there in the first quarter of 2020. A unit has gone to Indonesia, to a pipeline company. A major contractor in Japan is wanting one and they are coming down next month to see it in operation and talk through the details.”
The R-series of lifting bars produced by technology company Verton Australia addresses the same problem. “Unprecedented advances in the application of technology to crane-suspended loads” is what they claim. And “the biggest improvement in productivity since the crane was invented.” Clearly they have a product they think is important.
“The basic principle is to remove taglines from suspended loads,” says managing director Trevor Bourne. “They are risky and inefficient. We saw how tagline operators would be involved in serious or fatal workplace incidents. And we asked “How can we reduce the risk?’’
The answer, as before, is to keep riggers away from the loads. Let the machine do the turning. Verton calls its product the R-series. “It was invented by our founder and chief technical officer Stan Thomson, who has been in the business 35 years,” says Bourne. “He thought there had to be a better way to do this. In 2015 he started the company to come up with a concept. We have been doing R&D since then, until the middle of last year, when we went into production; and development is still continuing.
“We have two products: the 5t capacity R5.1 lifting beam and the 20t R20.1.” Their device looks different from its competitor’s: it is long, suspended horizontally by two ropes from the crane hook. It looks more like a spreader bar, and indeed functions as exactly that. Unlike a normal spreader bar, however, it also rotates the load to whatever orientation is desired.
Like its competitor it uses angular momentum and the basic laws of physics, but in a different way. The momentum is stored in gyroscopes rotating fast inside it; each unit houses several gyro modules, which are controlled remotely by an operator on the round with a hand-held device.
“When a command is sent to orientate a load, sensors and telemetry interpret the real-time load movement and the software does the rest,” says Bourne. “The gyroscope modules can be multiplied; you can add more to make the R-series scalable to any size of suspended load.”
The R-series also uses technology developed for electric cars. “In the last few years, improved batteries and control systems have given significantly more power,” says Bourne. Batteries on the 20t model give eight to twelve hours operating time. Rotors take two to five minutes, depending on the capacity, to get up to useable speed. “Smart sensors and cameras record your load and connect to the internet, so you can have a lift going on in New Zealand and sit in your office in Sydney or London or wherever and see your lifting operations in real time. Lifts can be delivered to GPS coordinates, and the whole operation is integrated to your load, your construction project, and your software.
“On a Christchurch, New Zealand, high-rise site they were installing 16 concrete panels a day. They brought in a R20.1 and now they are installing 26 panels a day. It has saved seven people on the site; they are three weeks ahead of schedule; and it has paid off its costs already, just on the one job.
“It has been on the market since February this year; it is in Australia, Europe and the US, so we are worldwide now. It is going extremely well. At the beginning of 2019 we were able to present the technology to the port of Rotterdam and we are working with the Danish wind turbine suppliers Vestas. In June this year we joined forces with van Oord, the global marine contractor, and with Mammoet to develop the concept. We now have offices in Rotterdam and in the UK. We demonstrated the system to civil engineering company Sir Robert McAlpine and gave another demonstration at the Thames Tideway Tunnel project in Wapping, London.”
Port installations are one area of interest. Dr Andrew Miller, who with Stanley Thomson founded the Verton group and created the device, says: “In a simple case study, a 50% saving in hook time translates to around 20% of time spent by a ship loading and unloading in port.
“As well as our 5t and 20t models we are developing the 30t, 60t and 120t capacities—the 30t will be available in the first quarter of 2020,” says Bourne. “Because the system is modular it can handle large bridge beams, 40ft containers and the like.”
Other claimed benefits are that the R-series cuts the time needed to move a load by up to 25% and gives full return on investment within 12 months. “The R-series is set to become the benchmark load management system worldwide,” says the company.