Trewes Commodore 32 | Full Electric

The removal of the old diesel engine was no easy task.

• The engine mounts were completely rusty.
• The fuel system had to be completely deleted become.
• The propeller shaft and adjustable screw were worn and had to be replaced.

New electric motor installed
The choice fell on a powerful electric motor, suitable for quiet and silent sailing.

Battery pack

• The boat received a battery pack with sufficient capacity for 6 hours of sailing.
• Charging via shore power and solar panels.

• The SABB motor (serial number G 68 820) was in few hours dismantled.
  • The number 68 refers to the year of construction, 1968.
• The engine was sold second-hand.
• He was completely overhauled, redecorated and runs reportedly still in top condition.

During disassembly, it was discovered that the screw could not be retained in its entirety.

• Some remained fixed to the boat, because this was used for the lubrication of the propeller shaft.
• The old lubrication system with two grease pots was left intact.
• The old screw was anchored to the hull and was used to adjust the propeller blades for forward and reverse sailing.

This system was then poured into the boat with concrete, making removal a big job would become.

The opportunity was taken to discuss the thoroughly clean the area under the engine and to painting with Primocon.
After a half century had been in the bilge collected quite a lot of dirt, including screwdrivers.
This job went exceptionally smooth:

• Without too sanding became a fast and opaque layer of Primocon paint applied, after the surface defatted was with car brake cleaner.
• Redundant parts, such as the diesel tank, filter and water tank, were deleted to make way for the new device.

The installation of the previously mentioned electrical components (see VAREN, June 2024 edition) took around five days occupied with two persons.

• The welding up the old skin penetrations (exhaust gas and engine water cooling system) and installing a steel tunnel for the bow thruster lasted day and a half.
• In the meantime:
  • The underwater ship fitted with a new antifouling.
  • Paint damage sanded, filled and repainted.

The space formerly occupied by the 80L diesel tank was taken, is now padded with three battery units on port side.
An additional battery unit was starboard, along with the MultiPlus.

Because the lithium batteries operate at 48V, was a custom charger needed.

• The existing 12V battery charger was redundant.
• A Small 12V house battery was retained to maintain the operation of instruments and lighting ensure.
• This battery is now charged via the 48V battery bank with a Victron Blue Smart charger.
• The previously installed 2000W inverter (230V from 12V) became redundant, as the new 5000W inverter integrated into the MultiPlus II.

The lithium batteries stay in top shape if they connected to shore power are.

Key benefits:

• The charge status can be monitored remotely via a modem and Victron VRM app.
• In the winter can be a special charging profile are used, with the batteries be charged up to 70%, but only above 5°C.
• Lithium batteries can be discharged up to 100% and do not suffer from the memory effect such as lead-acid batteries.
• Capacity loss is only 3% per month.
• After six months without shore power, some 80% of battery capacity is still available (unless devices remain 'online').

The basic slumber consumption of the current installation at the Starfish is 0,5A.

• This means that the full battery capacity would be consumed within a month without shore power (20 kWh = 400 Ah).
• Cost of a kWh depends on supplier.
• Running online devices will cost around €5-10 per month in 2024.

When installing electrical components in a wet environment is good grounding essential, both:

• When using shore power.
• When sailing on its own power supply.

In the initial renovation of the Starfish became a galvanic isolator installed to the grounding the shore power, so that these no longer attached to the engine/hull.

Now the old engine block removed was, a new earthing be installed:

• Floating mounting was chosen:
  • The negative pole of all electrical components was interconnected, making the entire installation forms its own grounding.
• By not attaching the earthing to the steel body, electrolysis is suppressed.
• Additional magnesium anodes (for freshwater) and a zinc anode were added to further reduce corrosion.

The installation of the compact electric motor had additional space, despite the:

• Water cooling (left)
• Motor controller (rear)

During the conversion, the Bellmarine electric motor installed, which much more compact is than the original SABB 1G diesel engine.

• As a result, there was lots of free space in the engine compartment.
• The extra space was partly filled by the voluminous water cooling and motor controller.
• The engine was placed on the existing foundation, which required few adjustments.
• With additional steel angle irons the engine was well aligned on the propeller shaft.
• Minimal vibration, friction and noise were achieved by careful alignment.

Above the engine remained sufficient space left for other installations, but this needed further be considered.

The first test run after the launch in January 2024 was immediately a success!

• The boat feed silently from Rhebergen shipyard about the IJ, via Amsterdam canals and the New Meerschut lock to the New Lake.
• The energy consumption was hardly measurable At a speed of 4-5 knots.
• Full throttle: the stern sank noticeably deeper into the water At a speed of 7-8 knots.
• Full stop with backlash could within one boat length.
• The bow thruster immediately proved its worth:
  • Easy transverse mooring at the quay.
  • Ideal for solo sailors who want to be less dependent on a crew member.

The shipyard E-WERF, located at the Nieuwe Meer in south-west Amsterdam, is a ideal test base for boating trips.

• After the arrival of the Starfish were all systems reviewed, tested and reprogrammed.

Retrieved from E-WERF works a team of four to the conversion of mainly sloops.
The yard is very busy, because all Amsterdam boats must have an electric motor by 1 January 2025!

The conversion of the Starfish For them, the first sailing boat, but not their first 32-foot vessel.

• The team is young, but did the technical knowledge largely learned by doing.
• Some employees made a career switch and have the skills gained in practice, as specific training for electric motors has only recently become available.

This lack of specialised shipyards causes many boat owners to wait to convert.

• Cost and knowledge gap are currently large barriers For voluntary electrification.
• Sooner or later electrification will become mandatory, making more demand will arise for expert recruiters.

Currently, some yards are trying to bring in customers by using price as the main asset.

• Number of working hours often underestimated, making the total price artificially low is held.
• Parts prices are transparent and verifiable online.

This report highlights that:

1. Installations must be completely safe.
2. Attention and time should be given to careful planning.
3. Correct installation of electric motors and components is essential.

E-WERF: a positive experience

The conversion of the Starfish by E-WERF became as experienced very positively.

• The team consists of four honest and motivated professionals.
• They are constantly learning and striving for the best results.
• Pride in their work visible in the final result.

"A dream team!"

At the estimating the cost of conversion was taken into account several factors.