Siemens Improves Granada Material Handling’s Operations

Industrial lifting company Granada Material Handling (GMH) has partnered with Siemens to improve its sea operations serving offshore wind turbines around the UK coast.

GMH was using a ‘marinised’ version of a standard winch and decided to redesign from the ground up to provide a more tailor-made solution.

The resulting Granada foundation davit sits on a wind turbine platform, part-way up at the base of the blade tips, on the access platform which is permanently in place.

The crucial factor is that the unit, when lifting loads varying from maintenance kits to tool bags, must align itself to the position of the boat, which is semi-moored to the turbine base, and must not allow the load being lifted to lower back into the moving boat deck at any point in the unloading process – especially if the boat breaks free from its moorings for any reason.

This requires an extremely fast accelerator on the hoist. Siemens was able to review the complete drive train for this transition piece davit along with Siemens Solutions Partner Iconsys, and to provide the ideal solution for GMH.

The resulting hoist can handle up to 1 tonne of load and features an IE2 Siemens Simogear 4kW geared motor with output speed of 19.8 rpm and gear ratio of 73,640:1.

Iconsys designed and built the control system for the davit, using the Siemens Sinamics G120, PM240 Power Module with built-in brake chopper and CU250S-2 PN control unit with integrated safety and ProfiNet communications.

The design of the control system for the project was split into two elements: the main drive panel, housed within the structure of the turbine tower, and an IP66 warning board fitted to the side of the davit crane and located outside the tower in a harsh marine environment.

The warning board includes an emergency stop button, siren, three-lamp LED tower and plug connector for a removable operator pendant. The pendant was designed with a 12-metre flexible cable, to be removed and stored when not in use.

Space in an offshore turbine tower is always tight so the main drive panel had to be very compact. For the crane control, in-built digital and analogue IO on the control unit meant a separate PLC was not required. This controller is the latest generation of hardware for the Sinamics G120 and now includes an encoder input feature which was critical to the over-speed safety requirements of the system.

A Siemens Sirius safety relay was also incorporated for the safe brake relay. All Siemens components were designed to work together to optimise performance, maximise safety and reliability, and minimise maintenance requirements.

Siemens integrated drive systems (IDS) provide real solutions for customers by ensuring that all drive train components are perfectly matched to the application and loading requirements. This in turn ensures reliability and efficiency throughout the product lifecycle, plus planned maintenance and significant long-term savings.

For the Granada foundation davit, some extra safety features were also built in by Iconsys.

Siemens account manager Nathan Adams has worked closely with GMH for over two years, helping to develop the Siemens system that, fittingly, is now being used to service Siemens offshore wind turbines. He commented: “With such a challenging environment, Granada Material Handling needed the reassurance of a fully integrated system that works perfectly under all conditions. With the Siemens integrated drive system and high level of quality assured products and systems we were able to provide this.”