Safe all round
25 April 2008
An array of products to make lifting work safer is available to crane users in many different formats. Safe operation of cranes is not restrICted to operator harnesses and load moment indICators, and users are being presented with innovative ways to make lifting machines safer.
Operator hoists on tower cranes are mandatory in several European countries, including the Netherlands, Denmark, Sweden and other nations are considering legislation that would make them required equipment. As a result, German hoist manufacturer Geda-Dechentreiter has launched a crane operator hoist, the Geda-Combilift 2PK, whICh, the company claims, meets all current European machinery directives.
The Geda-Combilift 2PK is a rack and pinion hoist with an aluminium track. The flexible system, Geda says, allows the hoist to be installed on any crane up to 120 m high. Models for taller cranes can also be supplied.
The hoist transports 200 kg or two people at up to 25 m/min. Safety is improved, according to Geda, in a number of ways, including a speed limitation system, security elements to prevent improper operation and a ramp that automatICally lowers every time the cage door opens to provide the operator with safer access in and out of the cabin and hoist. The lifting path is limited above and below by limit switches. An extra switch is fitted to further increase safety.
Geda also says that the modular hoist is quICk and easy to attach to a crane. To increase lifting height the hoist's rack sections are added through an opening in the roof, whICh allows the 22 kg track elements to be installed simply and safely. The track sections are connected, without screws, using a Geda-patented fast locking system and specially developed fasteners for “no-stress” attachment to the crane. The track sections make use of an integrated cable channel that guides the trailing cable along its full length
In the background
Not all methods of making lifting work safer are as obvious as an operator hoist, and a range of new components are available that each add something towards safer crane operation.
Rayco Wylie's i3000 rated capacity indICator (RCI) can be supplied with a data logger that records all crane parameters during lifts. The module offers a full and detailed summary of each lift more than 20% above safe working load. It can also provide data on running time, warnings and specified lifts.
The information is analysed via software on CD rom from whICh charts, tables and reports, can be produced that summarize data filtered or sorted by date, by crane operator, or by crane.
Manufacturer Rayco Wylie claims that the RCI manages crane maintenance as tables summarise the information concerning the life of the crane, for example, the number of lifting cycles and how much load it has been subjected to during its life. It can also be used to manage fleets or, simply, as a tool to rely on for information, for example, details of who was operating the crane when an accident occurred.
For crane rental companies, the information can be used to invoICe customers according to loads lifted or actual working time. Companies can also charge extra for overloads.
The data may be downloaded using a small portable data storage devICe (DL 3000) and then downloaded to a computer, or taken directly from the data module straight to a local personal computer if there is one available at the crane site.
Penny & Giles has a new CAN bus output option for its range of JC6000 multi-axis joystICks. The company says that demand from operators for improved effICiency, responsiveness and functionality from their vehICles is driving OEM manufacturers towards using CAN bus systems improve control systems in off-highway construction, munICipal and agrICultural vehICles.
There is also a CAN bus facility where additional input pins are provided in the joystICk mating connector, allowing non-CAN bus features to be connected directly to the bus network without needing an extra node. This enables a system integrator to design smaller and neater joystICk interfaces for applICations such as machine armrests.
The CAN bus option uses two Hall Effect sensors in each of the XY axes to provide safe, reliable operation with the long life benefits of this contactless technology. This safety is further enhanced as signal integrity checks are carried out within the joystICk.
Safer crane operation is the goal of Palfinger's new Integrated Stability Control (ISC) system, whICh assists crane operators in achieving a better degree of stability when working in cramped spaces. This new system is available for all Palfinger cranes with hydraulICally extendable outriggers.
Palfinger's ISC system is an all-in-one solution, allowing all the crane's stabiliser legs to be controlled at three outrigger positions - retracted, half-extended and fully extended. The stabilisers can also be controlled not under load and under load. The user can see the status of the stabilisers on an easy to read display panel.
Depending on the position of the crane boom, the lifting forces are restrICted to the current stability support situation. The technICal components of the ISC include a rotary transducer, a stabiliser support sensor system and the PaltronIC 50, whICh handles the evaluation electronICs.
Give warning
Cattron Group International has developed a Man-Down alarm feature on radio remote control systems for overhead cranes and other industrial machinery. The alarm is a backup safety feature designed to activate automatICally if an operator falls or becomes incapacitated. It works using a tilt switch in the remote control's transmitter. If the transmitter remains tilted for more than five seconds, an emergency shutdown of the controlled crane or machinery will be initiated. At the same time, the Man-Down Alarm function generates a synthesized voICe distress message broadcast via a user-supplied two-way radio on the equipment being controlled over a plant or facility-wide communICation network. The distress message is repeated until the alarm is manually reset or for a maximum of 10 minutes.
As an added feature of the alarm function, the broadcast distress message includes a call sign indICating whICh transmitter the alarm is coming from. This is partICularly useful where there are multiple remote control systems or if the applICation requires two operators, each with a transmitter. In the case of certain overhead travelling crane applICations, a pitch-and-catch function allows two operators to transfer control of the crane between each other, typically in situations where it would be unsafe and ineffICient for one operator to accompany the load for the entire move. The call sign identifICation provides immediate indICation of whICh operator has caused the alarm.
The Man-Down alarm is a standard feature on Cattron radio remote controls for locomotive applICations and compliments other built-in safety features to help ensure safe, secure operation of the controlled equipment. The alarm will be offered as an option on new remote control systems and as a retrofit option on some existing ones.
Another new safety alarm system is from Brigade ElectronICs, whICh has introduced a range of multi frequency broadband alarms (BBS-tek). Brigade says they are “fast becoming the audible reversing signal of choICe for a wide variety of applICations.”
Broadband sound, the manufacturer claims, is more effective at alerting to imminent danger, while actively eliminating noise pollution. It is locatable, instantly pin-pointing the direction of danger. It is only heard in and around the immediate danger area. BBS-tek's multi-frequency range spans from 400 to more than 10,000 Hz, avoiding the aural hazards and irritations resulting from shrill narrowband sirens. •