CONTROLS AND SENSORS Ӏ EQUIPMENT FOCUS
with that. But the metal hardware of old cranes is often still perfectly serviceable. So rather than spend six million euros on a new crane they spend perhaps two million euros to refurbish and upgrade the old ones and give them modern digital control systems; which is where we come in. “And offshore, North Sea safety
j huge data streams from their cranes that digital sensors provide. They expect the vast amounts of performance and risk-analysis data that machine-learning software can give them at the touch of a button. They want a continuous stream of speed and temperature and vibration and load and strain data; and the pre-digital control systems are just not compatible
The operator’s
view on Autec’s 4.3” display screen on the AVS
regulations require such things as automatic overload protection, so that if your crane hook catches on a supply boat and tries to lift it, the rope is released from the winch instead of continuing to tighten and capsizing the crane or the support vessel - which has happened. And digital is the only real way to provide that protection. So offshore operators also need the latest control systems. We do the upgrading.”
Safe and legal: keeping the operator in control
Irugasa has been distributing remote controls in the UK market about 20 years, first as sole agents for Ikusi and now also for the Danfoss brand. Michael Ainsworth is sales and marketing manager. “80 percent of what we do is retro-fitting,” he says. “The first question you ask a client is ‘what do you want your crane to do?’ “If it is a gantry that moves forward, back, left and right, that’s fine; there are standard solutions for that. You can get variations: below the hook equipment like grabs, coil lifters, magnets can all be operated remotely as well. But you do need to know the equipment is there and how to manage it. For example, our controls for a magnetic lifter have one button for ‘on’ and two separate buttons for ‘off’, and those two have to be pushed simultaneously and they are never next to each other. That way they cannot be operated unintentionally; so the magnet cannot turn off and drop its load by accident. “You can set the operating range of a remote, so that if the crane is more than so many metres
from the operator it will shut down. That way the operator is always in control. “Our own controls have an additional safety feature. The signal to perform a movement is in three
parts. There’s a ‘command coming’ signal; the receiver has to reply to that with a message of its own, and then the final command is sent. Only when all three parts of the message are received can operation then happen. “The bottom line is that remote crane control is much safer than
conventional methods, as well as being more efficient and cheaper. Reputable control systems will all have a ‘fail safe’ design, so that if there is radio interference, or loss of signal, the crane will neither run away nor drop its load. Those are legal requirements, set out in the UK Radio Equipment Regulations 2017. Sadly, as technology becomes cheaper and easier to make, not all equipment on the market complies with it. Any buyer should make sure that compliance certification is on the documentation. “The current demand among users is for increasing back
communication. Owners are very much into asset management; they want to know what their crane has done, what loads it has carried at what speeds, what it did last week and what it is doing now. Telemetry in radio control systems can provide that; there is a lot of R&D in the pipeline just now and that maybe our most valuable future portfolio.”
Mohammed Ahmad, automation engineering lead at Alatas, takes up the story: “So what we do is strip out the old systems and install fibre-optic cabling, sensors, cameras, software, all the works; and we might add a new cabin where the operator can do everything with joysticks instead of hydraulic levers and see everything on screens. And, of course, we replace any worn-out parts of the hardware – bearings, gearboxes and the like – while we are at it. We put in encoders that measure rope and winch speed, and angle sensors on the boom, and load cells which measure the strain on the ropes; and feed all their data back to a PLC (programmable logic controller). It is like taking an old ‘70s Mustang car and putting Ferrari electronics into it.” f
40 CRANES TODAY
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