Page 42: of Offshore Engineer Magazine (Mar/Apr 2022)

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TECH FEATURE HKZ

Photo by Bartolomej Tomic

TenneT’s

Substations

Getting

Ready for

Vattenfall’s

Giant

Of shore

Wind Farm

By Bartolomej Tomic enneT, an electricity transmission system op-

Drif ing Bulk Carrier erator with activities in the Netherlands and in

However, just a month before the installation, the HKZ

Germany, late in March installed the topside of Zuid Beta project faced a scare when the drifting Maltese- the second offshore transformer platform built registered Julietta D cargo ship hit the HKZ Zuid Beta

T to serve Vattenfall’s giant Hollandse Kust Zuid offshore jacket in stormy weather.

wind farm in the Dutch North Sea.

A total loss would have caused a lengthy project delay

Following the installation of the ? rst transformer plat- and hefty additional costs, Offshore Engineer understands, form, the Hollandse Kust Zuid Alpha, in December 2021, as it would’ve called for a new jacket to be built and mov-

TenneT had offshore installation ? rm Allseas install the ing and securing the topside ashore, as well as potentially 3,950t Hollandse Kust Zuid Beta topside on a 44 meters having to face an issue of not having a suitable installation tall, 2,900t jacket previously lowered on the North Sea sea- vessel, as the Pioneering Spirit, due to its own schedule and bed in the Dutch North Sea.

other projects, might not be nearby for the second attempt.

On what was a rather foggy Monday in the North Sea

Luckily, a subsequent inspection by TenneT proved that off Scheveningen, Allseas on March 28 used its 382-m Pio- the jacket suffered only minor damage, and that it was safe for neering Spirit installation vessel, a true behemoth, to lift the topside to be installed, thus avoiding any potential delays.

the HKZ Zuid Beta topside, and lowered it on the jacket.

TenneT inspected visible damage above water, but it also

The topside had arrived from Dubai, where it was built carried out underwater surveys to determine any damage by Petrofac and Drydocks World, to Rotterdam aboard to the substructure.

Boskalis’ semi-submersible heavy transport vessel Mighty “This underwater investigation took more time due to rel-

Servant 3 just days before the installation, which, accord- atively high waves and poor visibility. The investigation now ing to Allseas, went quickly and smoothly.

shows that the damage is limited to paint damage and a few

Per Allseas, it took only three days between the loading dents on one of the legs of the platform and damage to one of of the Beta topsides aboard the Pioneering Spirit in Rotter- the four landing platforms for working vessels,” TenneT said.

dam to ? nalizing the set-down and welding onto the jacket.

Announcing that the jacket is safe to receive the top- 42 OFFSHORE ENGINEER OEDIGITAL.COM