GPS synchronises upgraded navaids

Offshore production at Ekofisk began in 1971 but today the operative parts of the complex consist of multiple areas: bridge-linked accommodation, production, well head, drilling and processing facilities. Since some of the complex is keeping its original Tideland aids, the new equipment has had to interface with the much earlier technology, plus other manufacturers’ equipment either on the complex or temporarily tied up to it. This has been helped by the company’s development of a GPS synchroniser that has a programmable timing offset, giving the new system the ability to synchronise with other less flexible equipment.

‘GPS is the only real option,’ Tideland Signal’s Paul Burford told MJ, ‘because if you look at linking it all together with cable, it becomes a truly mammoth and complicated task.’ He added that the clever thing here is the injection of the timing offset. In theory all applications ‘listen’ to the satellite signal and should start together. ‘In practice, he says, ‘different systems listen to different part of the signal. But the saving grace is they all have the same 15 second duty cycle, which means if you delay some of the beacons, you can still get the flash to synchronise.’

While an earlier installation protects the northern end of the Ekofisk complex, the new systems, also from Tideland, have been installed on the various structures running on from the 2/4C platform to the South Flare stack.

Two Syncrolan light stations, incorporating a MaxLumina ML-300-SL-400-Ex main light and ML-300 Ex secondary light, have been put in at either end of this chain of structures. The Syncrolan on the 2/4H platform is equipped with local controls while the one on the South Flare is controlled from the 2/4W platform.

A further six subsidiary lights are located along the bridges and other structures from the Number 3 Bridge Support southwards.

All the secondary and subsidiary ML-300 Ex lanterns are supplied complete with LC6Ex six place flasher lampchangers. The flasher units are housed externally in a stainless steel Exd enclosure wired to a stainless Exe junction box and mounted on a stainless pedestal. A remote monitoring and control panel installed at 2/4C provides alarm warnings to indicate if any of the lights should fail.

Amongst the other pieces of Tideland equipment previously supplied to Ekofisk are two SeaBeacon 2 racons. These are used to mark the two booster platforms on the 275 mile gas pipeline from the complex to the Emden Terminal in Germany.