In pictures: new WTI concept by Huisman

Two pairs of tuggers work in unison to control and position the load, or turbine blade.

One pair is fitted on independent trolleys that can travel along an integrated rail along the crane’s stiff boom. The trolleys automatically follow the main block to maintain an optimal tugger line configuration while the second pair of tugger lines is deployed from the crane tip, providing a force perpendicular to the first pair of tuggers.

By approaching the load from two different directions, the system provides significantly more control than a conventional single pair of tuggers.

A specially designed control system holds the actual position of the load, resulting in a much stiffer restraint, and therefore a higher position accuracy compared to conventional tugger systems that rely on constant tension. In case of an unexpected overload, the system will give way but will return to its position setpoint when the force drops below the threshold again.

“This is crucial for the technical readiness of next-generation offshore wind turbine installations, even under challenging wind conditions,” said Jesper Moeller, chief engineer Execution at Siemens Gamesa. “The resulting increase in installation uptime will be accompanied by a positive effect on the operational activities in general, as well as increased on-site safety.

“Siemens Gamesa sees the system as a potentially new industry standard with benefits for the whole wind industry, providing more productive vessel days, while at the same time reducing (de-)mobilisation times. Hence, Siemens Gamesa will consider the availability of the new Travelling Load Stabilising System on installation vessel cranes as a significant factor in decision making when selecting/hiring appropriate installations vessels in the future.”

“The only way to accelerate the energy transition is through innovation enabled by the joint forces of industry partners,” said Huisman CEO David Roodenburg. “With the Travelling Load Stabilising System, we are very proud that together we can offer installation companies an efficient solution to reduce weather downtime, a challenging and delaying factor of wind turbine installation.”

Huisman says the system gives effective load control because the tuggers are at the best elevation, and the boom trolleys have a much higher stiffness compared with flexible tagline, increasing control and workability.