Seaworthy drives make marine engineering easier

Components and systems for maritime applications must be especially rugged and durable because of their continuous exposure to a moist, salty atmosphere. In addition, suitability for widely differing operating temperatures becomes necessary for ships that pass through several climate zones. Navalimpianti, an experienced Italian marine equipment provider, used to individually select and procure all required equipment including electric drive components. All configurations and adaptations of the drive systems were then done in-house to comply with rigorous demands, all to ensure totally reliable performance for many years. Obviously, this required a very substantial effort.

All of that changed almost instantly when Navalimpianti found that drive provider Nord Drivesystems was able to flexibly implement the required options from their standard catalogue, and supply suitable drive systems everywhere in the world. Navalimpianti not only found the high gearbox quality and reliability more than satisfactory, but especially appreciated the German drive manufacturer's readiness to implement specifications such as IP66 ingress protection or stainless-steel output shaft fittings. A number of other application-specific features were then jointly defined by the customer and Nord, whose engineers were able to draw on decades of experience and advise on the optimum drive selection and configuration.

Rain or shine - drives move Skydomes

Individually designed for each ship, Navim Skydomes are a stand-out product in the portfolio of the experienced passenger vessel outfitter. These elegant sliding glass roofs are composed of numerous movable segments and are equipped with a motor. When they are completely closed, they keep out wind and rain and enable air conditioning of the upper deck. The glass roofs add value to any cruise ship because they allow the year-round use of outdoor swimming pools, which are among the main attractions for many travellers. They are opened and closed gently and quietly by specially configured Nord drives. Two or four parallel-shaft geared motors are used depending on the span and weight of the roofs. In addition to a high resistance to maritime climates, these drives must withstand the chlorine-saturated atmosphere around the pool. Notably, they must ensure failure-free operation for many years, because once the roof is installed, they are not easily accessible for maintenance or repairs.

Drive over board - window cleaning on the high seas

Moving window cleaning platforms into position is another task Nord drives take care of. Silvano Lonzar, chief designer at Navalimpianti says: "We are outfitting two ships right now, one with six and one with seven motorised window-cleaning platforms for the ship's right, left, and stern side." Four bevel and worm geared motors per window cleaning system power the winches that move the platforms horizontally along. The worm-geared motors are self-holding and therefore need no brakes to stop. The fans of the vertically installed motors are protected from rain ingress by double canopies. Further safeguards in this outdoor application and its salty and chlorine-saturated atmosphere include terminal boxes sealed with epoxy resin and stainless steel hollow shafts. A five-layer coating for offshore operations with sturdy multi-component paints ensures class C5 corrosion protection according to EN 12944.

Satisfied end customers

Over the years, Nord systems in Navalimpianti products have proven their mettle in numerous installations. The drives can be directly installed and put into operation by the OEM without any extra engineering effort. Commissioning has also become a smoother, more efficient process with Nord products, because the drive systems do not require a separate acceptance test or end user training. Lonzar says: "The reliability of Nord products boosts our own overall reliability for our customers. In fact, since we have been using Nord drives, we have experienced no service call, no drive failures. Our group image benefits greatly from that. What is more, Nord is able to fulfil our wishes very quickly and supply suitable solutions. In the past, we had to wait a long time until drives were delivered with documentation according to our specifications. From our experience, NORD can usually configure a standard drive from their catalogue straight away. So, the selection takes little time and the delivery times are very short. Since we do not have to build weather-proof housings for the drives anymore, we save a significant amount of time."

Working with the Italian subsidiary of the Nord Drivesystems Group, Navalimpianti can rely on the manufacturer's global sales and service network. This, too, is important to Lonzar: "Before we chose Nord, we made sure to confirm they could supply products and materials in uniform quality around the world. In this regard, as well as in respect to cost efficiency, Nord passed the supplier selection process with flying colours."

To learn more about drive systems from Nord, go to www.nord.com.