Renishaw reflectors are essential to achieving optimum performance from your Fanbeam 5 laser DP position reference system.
Essential for successful operations
The Fanbeam 5 sensor emits invisible, high-frequency laser pulses over a 360° angular range. Quick-to-mount reflectors, attached to moving or stationary platforms or vessels, return these laser pulses back to the sensor.
The sensor uses these returned pulses to measure the range and bearing of the reflector from the sensor. Fanbeam Controller 4.0 applies operator-controllable filters to these observations and those that are selected as targets will be communicated to the DP system.
Designed to work effectively
Our Fanbeam 5 laser sensor, custom reflectors, and Fanbeam Controller 4.0 are designed to work together seamlessly. Understanding how the reflectors contribute to the optimum performance of the Fanbeam system can help customers complete successful DP operations quickly and safely.
Technical drawings covering prism clusters and reflective tubes, mounting and positioning are available when you contact us, as well as support, specifications and pricing information.
Fast and effective dynamic positioning
A reflector can in theory consist of any fixed reflective surface. However, optimum performance demands powerful signal return, and we therefore recommend the following two reflector types:
- Renishaw prism clusters: Highest performance at long range
- Renishaw reflective tubes: Optimum for cost-effective short-range use
Renishaw reflectors have been used for the full range of DP operations on a variety of offshore support vessels, and are proven to offer the following benefits:
- Speed and security of mounting: Renishaw reflectors remain secure once fitted.
- Flexibility of mounting: Renishaw reflectors can be mounted on fixed or mobile structures on a permanent or temporary basis, with minimal maintenance required.
- Precision engineering: Renishaw reflectors are engineered to ensure optimum performance with the Fanbeam 5 sensor.
Our high-quality marine-grade prism clusters are designed to support long-range DP operations:
- Identify and lock on to the correct observation quickly
- Track with confidence and minimise tracking loss due to the very strong signal return delivered by our prism clusters
- Reconfigure quickly and easily to extend angular coverage, giving flexibility for a range of operations
- Prism clusters have a long lifetime, with minimal maintenance
- Use Fanbeam 5 over a range of 2000 m, beyond the installation 500 m exclusion zone
|Cluster type||Angular coverage|
|4-way prism cluster||105°|
|6-way prism cluster||150°|
|8-way prism cluster||195°|
|10-way prism cluster||240°|
|12-way prism cluster||285°|
|14-way prism cluster||330°|
|16-way prism cluster||360°|
Configurable for complete flexibility
Our prism clusters consist of an engineered 'tree', designed to enable users to mount our marine-grade retro-reflective prisms in pairs, stacked vertically in offsets of 45°. By changing the number and position of prisms, which is quick and easy with no special tooling required, dynamic positioning operators (DPOs) can optimise reflectors for different operations.
This simple solution allows DPOs to take into account the relative height of the vessel and the platform, as well as the bearing on approach for complete flexibility.
All prism cluster arrangements are supplied in a transit case, allowing for safe and easy transport offshore, or storage if not in use. A metal mounting arrangement is also supplied, which allows for simple attachment to a handrail.
Maintenance consists of a simple inspection to ensure that the prisms are clean and that the mounting arrangement has not come loose.
Single prisms can be purchased individually to extend angular coverage of existing cluster or to replace any lost or damaged prisms.
We recommend Renishaw's custom reflective tubes for general short-range use, from a 10 m minimum range to a maximum operating range of 150 m.
The tube reflectors consist of diamond-grade reflective tape wrapped in a vertical orientation on 1 m long aluminium tubes. The materials and construction of our reflectors ensures a high level of signal return to the laser sensor at shorter ranges.
One-ton shackles at either end of the tube allow for deployment by crane and for easy attachment to a handrail or other structure on the side of an offshore installation. Reflective tubes are sold in pairs, in a transit crate, for ease of storage and transport.
All tubes require regular basic maintenance to ensure that salt deposits do not build up and impair the tube's reflective properties.
How to position reflectorsDPOs with experience of laser sensors understand that the position of the reflector is of utmost importance, since poor location can lead to degraded positioning or loss of tracking during operations.
DPOs working with Fanbeam and our training materials quickly learn how best to position targets, and the performance indicators provided by the Fanbeam software will show if confidence is low and targets need repositioning.
Key considerations when positioning a reflector
The reflector should be roughly the same height as the Fanbeam laser sensor. This lessens the need for tilting and reduces the risk of target loss due to pitch-and-roll when working at very short range. Fanbeam 5's auto-tilt capabilities significantly increase DPO flexibility.
Fanbeam works best when the reflector is not too close to the laser unit. Operating over a very short range between reflector and laser unit (less than 10 m) can slow operations and is not recommended.
Even when mounting is temporary, a robust mounting arrangement should be used. Physical loss or damage to a reflector could prevent operations. It's therefore best practice to keep spare reflectors.
Reflectors must be mounted vertically. Incorrect alignment will degrade performance.
The sensor depends on a clear line of sight to the reflector for optimum performance. While Fanbeam 5's sophisticated software identifies and rejects 'clutter', for reliable operations the reflector should be positioned away from locations where moving infrastructure or personnel can block the line of sight.
All our reflectors are passive, simply reflecting the eye-safe Class 1 laser beam emmitted from the laser sensor. Increased personnel awareness of the purpose of reflectors will help to mitigate potential interference that could worsen any of the above considerations.