Big stability even bigger loads

Yachts like the latest Swan 88 have so much righting moment compared with their predecessors of even just 10 years ago that equipment loadings continue to climb even higher...

Modern hull shapes now have so much form stability that the loads on today’s large performance cruising yachts can be colossal. Reckmann Yacht Equipment, a long established German company with 132 years of expertise, is Nautor Swan’s long standing partner for this size of yacht and was therefore the obvious choice for the furling units used on this design.

Even though the new Swan 88 is intended primarily as a cruising vessel, headstay loads are around 16 tonnes, eight tonnes for the staysail, five tonnes for the headsail sheets and three tonnes for the staysail sheets. To put these figures in context, they are roughly double those originally encountered on 130ft J Class yachts that have three times the Swan’s displacement. Yet today’s 80-90ft maxi yachts need to be capable of being sailed by a skeleton crew, rather than the dozens of people that are often seen assembled on a J Class.

Easy operation of sail handling systems, along with minimal maintenance requirements that don’t over extend a two-person professional crew, are therefore paramount. At the same time, these systems must continue to perform their critical roles with unwavering reliability, even in the most arduous of conditions.

While Reckmann can produce custom units for mega yachts, CEO Marcus Schuldt told Seahorse this project posed ‘no special challenges for Reckmann because we needed only standard systems from our portfolio, with no modifications, for the Swan 88.’

Reckmann is rightly proud of its hard-won and strong reputation for reliability in all conditions. To achieve this it’s not sufficient for products to simply work straight out of the box. Continued reliability and dependability are equally essential. To ensure that this remains possible, even after many years of hard use, Reckmann offers an expert maintenance and repair service. As a precautionary measure, all parts liable to wear, including seals and bearings, can be replaced. After this, full functionality testing is carried out to confirm correct operation and that no other problems exist. Owners and captains can therefore be confident of their Reckmann systems providing safe and reliable service in the long term. Reckmann furling systems are expected for their first service at about six or seven years after installation. Some of them receive their first service after 20 year, still functioning perfectly.

The UD headsail furler range is widely regarded as one of the best available. A UD-4sc/RT unit, with the optional S5 double groove carbon foils, was specified for DreamCatcher, the first Swan 88 to launch from Nautor Swan’s legendary Pietarsaari yard. Schuldt says this model of furler is ideal for this application as it’s ‘a compact and powerful below deck hydraulic unit with light foils that save weight at the right spot’.

This is an important factor, since anything that reduces weight aloft simultaneously improves stability and reduces pitching, creating a more comfortable motion at sea while also boosting boat speed. Like all Reckmann hydraulic headsail furlers the UD range incorporates an emergency manual drive that can be operated safely at deck level using a standard winch handle.

Above: Reckmann’s under-deck headsail furler design is ideal for boats like the Swan 88 because it’s compact and powerful with lightweight foils.

Other key features include compact system size with an excellent performance to weight ratio and an integrated ram to tension the stay independently to the foils. There’s also a pilot operated check valve to keep the hydraulic lines pressure free when not in use, plus an inbuilt ultrasonic sensor that enables sail trimmers to identify the exact position of the adjuster piston, which allows the use of repeatable settings in different conditions.

The unit is mounted at the bow and includes a second, additional hydraulic circuit so the furler can be operated using a manually driven back-up hand pump in the event of a power failure. The system is available for all kinds of headstays with the stay disconnection system located above deck level for easy maintenance and de-rigging. It’s also suitable for both carbon and aluminium foils.

The second Swan 88 to hit the water has a headsail with a torsional cable and is therefore fitted with Reckmann’s UD4scRT/TC unit (TC in the model name here refers to the torsional cable), plus a TTS-4L titanium top swivel.

The TTS range of very compact swivels is a lightweight option for torsionally rigid forestays. Smooth running bearings ensure that the swivels turn with minimal lag, protecting the stay from strong torsional stresses, while units designed for working loads above 12 tonnes are made of titanium, which further reduces weight aloft. A choice of top connectors allows integration with a range of different rigging set ups.

Unlike a headsail furler, which must be able to withstand the huge loads encountered when the genoa is partially reefed, with zero risk of unfurling further, staysails are used in a binary fashion, either at full size or fully furled away. The Reckmann Staysail Furler SF specified for the Swan 88 is a combination of a neat rotating padeye at deck level and a below deck hydraulic stay tensioner, which enables this single unit to both tension and furl inner foresails.

Above: the Reckmann staysail furler combines a neat rotating padeye at deck level with an under-deck hydraulic stay tensioner

A neat self-aligning deck suspension system allows for an aesthetically pleasing flush deck installation while eliminating any risk of bending loads being imposed on the piston when it’s extended. The staysail furler is also equipped with a strong hydraulic brake and a removable stay connector with a quick release pin that facilitates fast sail changes.

DreamCatcher’s code sails are set using a Reckmann CZ-8/315 furler, which also takes the form of a furling padeye mounted below deck. ‘Its compact design and light weight make it ideal for all code zero and light wind furling purposes,’ says Schuldt, ‘and because of the high furling speed even large sails can be furled very fast.’ The furler is made of stainless steel, is protected against corrosion and can be mounted in the anchor locker thanks to Reckmann’s wide range of stay connectors.

Load monitoring is an increasingly important function today even on cruising yachts in this size range. Reckmann therefore offers a range of sensors and associated cables for its furlers and hydraulic cylinders. Real-time adjuster pressure sensors for instance allow the actual forestay loads to be measured and displayed on the yacht’s instrument system or logged for subsequent data analysis. These are stainless steel devices with a measuring range of 0 to 400 bar (0 to 5,800psi) and have analogue or optional digital outputs. In addition, adjustable ultrasonic sensors are used to determine the forestay length adjustment in real time and can also be employed to determine the tank capacity of hydraulic units.

Given the huge loads imposed by the Swan 88’s impressive stability and sail carrying abilities, how are these furling systems powered? Traditionally that’s done with a power take-off from a diesel generator that also runs refrigeration, air conditioning and other hotel loads such as watermakers. However, DreamCatcher, the first Swan 88, has a hybrid propulsion system with a massive 160kWh Deep Blue battery bank from Torqeedo and a 50kW electric motor to drive the hydraulic systems including bow and stern thrusters and the anchor windlass.

Compared with the loads associated with those systems, ‘our hydraulic units don’t need much power and can be easily driven by the power pack installed,’ says Schuldt. ‘You only need bigger power to furl the sails, which doesn’t take much longer than one minute and you don’t need any big power while you unfurl the sail.’

Whatever the application, Reckmann has a portfolio of wellsuited and flexible furling products, while custom units that are perfectly matched to larger applications can be created if necessary. All systems are backed up by unrivalled expertise that helps maximise both efficiency and reliability on board, without the need for unduly onerous servicing schedules.

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