Swan 55/57 CC – S/Y Night Train

Swan 55/57 CC – S/Y Night Train

"Our big engine refit has been implemented. We said bye to the 6 cylinder diesel engine and AC diesel generator. This was a multidimensional project; electric propulsion (combined with hydrogeneration), large lithium battery bank and big DC generator that cater for both silence while motoring and independence to run all systems for an extended period of time while under way and at anchor. A hybrid system was our choice, both from a safety and comfort point of view." – Johan Wentzel, owner of S/Y Night Train

The Swan 57CC (Frers) is a 56′ 11″ monohull sailboat designed by German Frers and built by Nautor (Swan sailboats) between 1990 and 1997.



"First sailing season with our new hybrid electric system behind. Some thoughts about our electrification project:

- Motoring: the difference in the sound level (especially inside the boat) is HUGE - this in comparison when motoring supported by the generator vs the old Perkins. The loudest noise is actually the prop itself.

- Propulsion power: we are actually a bit better in practice than on paper. We reach our typical cruising speed of some 7.5 knots well below 20 kWh. Responsiveness is instant when manoeuvring in ports etc. Great also in rougher conditions. - Range: we can motor some 1 - 1.5 hours (depending on conditions) from our battery bank. If required, our 22kWh DC generator provides power to take us as far as we have diesel in the tanks - that is above 1,000 nm if fully fuelled up.

- Hydro re-generation: our shaft drive is not the optimal set-up for this. However, we re-generate some 800-900Wh produced around 8.5-9 knots and some 350 Wh at 6 knots.

- Electricity onboard: our 28kWh battery bank takes us beyond 10 hours if we would run air-conditions, hot water etc. continuously. We still also have our 24V battery bank of some 12kWh, which powers the 24V side and also the refrigeration and freezer compressors. This is charged via DCDC converters from the 48 V side but can be run also independently providing extra buffer. When starting to run out of electricity the 22kWh DC generator pushes 22 kWh directly to the battery bank (very quietly). This compared to the old AC generator (very loud) providing 1.2kWh charging via the battery charger - basically useless. This dimension has made a huge difference on daily life onboard (as we prefer to anchor). We can run everything as we would be hooked up to shore-power - air-conditioning, water heater, fridge/freezer etc.

For the usability and flexibility of the boat has increased a lot - silence in all conditions combined with true electricity independence. Would I do it again with all the hindsight - yes, and would actually insist on it!" – Johan Wentzel, owner of S/Y Night Train

Technology used in the electric Swan 55/57 CC sail yacht:

  • Boatbuilder: Nautor
  • Length overall: 17.5 m
  • Boat beam: 4.85 m
  • Draft: 2.6 m
  • Displacement: 23600 kg
  • Electric motor system: Oceanvolt AXC40 electric shaft drive motor
  • Electric motor system nominal power: 40kW
  • Electric motor system voltage: 48 V
  • Batteries: 28kWh Lithium battery pack
  • Generator: 22kW DC

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