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Discussion Starter · #1 ·
I am refitting a rather odd boat, a Vaitses/Herreshoff Meadowlark. 37' long, 8' beam, 20" draft, two masts and leeboards.
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As originally designed she had two 5hp gasoline engines pushing two props. Somewhere along the line these were replaced with a single 27hp Yanmar diesel pushing a single offset prop.
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The diesel hasn't been well maintained, and with only one prop she doesn't handle well at low speeds under power, so I've been thinking about adding a pair of electrics. Both Torqeedo and EPropulsion make pod drives that would serve - with the shaft and cutlass bearing strut removed, either of these pods could be placed to put the pod's props where the existing prop and it's missing twin are and would have been.

But I've been thinking that perhaps a pair of electric outboards might do. EPropulsion's Navy 3.0 or 6.0 Evo, or Torqeedo's 3.0 or 6.0 R.

The advantages I see:
  • easier to repair or replace
  • can be lifted out of the water when under sail (when I'm not using the regen to power the batteries)
  • can be lifted out of the water at anchor or at dock, to reduce marine growth
  • can be steered, making for even more directional control at low speeds than simply have two props
  • can be installed, and tried out, without having to remove the existing diesel

The only major shortcoming I can see is that it would making mounting a windvane off the stern very complicated, but given the boat's stern configuration that'd have been true even if I don't hang engines off the back.

Are there any other possible issues I should be aware of? Between pod drives and outboards, that is. High price and limited range are very much relevant to the choice between diesel and electric, and I may we'll stick with diesel, but assuming I decide on electric, why should I choose pods over outboards?
 

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Herreshoff/Vaitses Meadowlark
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Discussion Starter · #3 ·
IMHO, the aesthetic of outboards hanging off the transom would spoil the beauty of that amazing boat.
That is a legitimate complaint. Meadowlarks were designed as simple, unassuming boats, free of glitz and brightwork. But that doesn't mean they have to be ugly.
 

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Discussion Starter · #5 ·
Electrics under any circumstances raise issues of limited range, source of charging, etc.

OTOH, internal combustion of any type are loud, messy, and require a great deal more maintenance.

But those have been argued to death. I'm asking about pods vs outboards, assuming the decision to go electric has already been made.

Disadvantages of outboards:
  • More likely to be damaged in a collision (but less likely in a grounding?)
  • Ugly

Others?
 

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Discussion Starter · #7 ·
A nicely cared for disel though can be a very reliable option, but I know you have already decided on electric, its just a matter now of inboard/pod versus outboard.
If I trusted the diesel had been maintained properly, over the years, I'd not be considering a change. But I know it hasn't been. After a couple of thousand in repairs, it's working now, but I'm less than confident in it.

I'm not sure whether I can live with the limitations of electric, either. That's part of what makes electric outboards attractive. I can put them in place without removing the diesel, and even after I do remove the diesel, swapping in gas outboards would be simple, compared to replacing pod drives.
 

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Discussion Starter · #9 ·
I suppose then the question is: How do you plan to use the boat? If you have specific goals the path is easier to see.
The goal is to use it as a retirement live-aboard, along the US East Coast, Gulf Coast, and excursions to the Bahamas, perhaps Dominican Republic, Puerto Rico, and the Virgins.
 

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Discussion Starter · #15 ·
If you’re refitting, is a single pod in the center of the boat a possibility?
On my boat? No.

She has a shallow but very long keel running along the centerline. This is part of why she steers so poorly at low speeds, given that she has only a single offset prop.
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Discussion Starter · #18 · (Edited)
It is all about the propeller. Which ever drive you choose, it needs a propeller with the right diameter, rpm and pitch to give the thrust needed for the yachts hull speed. Choose the propeller first and then select the drive that fits.
Some numbers:
  • ePropulsion Navy 3.0 Evo outboard - 3kW, 2300 max RPM, 10.2" 2-blade prop
  • ePropulsion Navy 6.0 Evo outboard - 6kW, 1500 max RPM, 12.6" 3-blade prop
  • ePropulsion Pod Drive 3.0 Evo - 3kW, 2300 max RPM, 10.2" 2-blade prop
  • ePropulsion Pod Drive 6.0 Evo - 6kW, 1500 max RPM, 12.6" 3-blade prop
  • Torqeedo Cruise 3.0 outboard - 3kW, 1100 max RPM, 11.8" 3-blade prop
  • Torqeedo Cruise 6.0 outboard - 6kW, 1130 max RPM, 12.6" 3-blade prop
  • Torqeedo Cruise 3.0 FP Pod Drive - 3kW, 1100 max RPM, 11.8" 3-blade prop
  • Torqeedo Cruise 6.0 FP Pod Drive - 6kW, 1130 max RPM, 12.2" 5-blade prop
The props on the Torqeedos are interchangeable. The 12.2" 5-blade prop from the 6.0 pod drive is optimized for low-speed displacement boats, and will fit on the 6.0 outboard.
 

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Discussion Starter · #20 ·
Power requirements are so non-linear, and battery life and range increases so much at lower speeds, I don't see hull speed as being my normal cruising speed.

I'd want enough power to achieve hull speed against chop or a head wind, in case of emergency, but I can't see myself carrying enough battery to do it very long.

The math predicts a smooth curve - lower power means lower speed and longer range. But it's almost certain that there will be certain power levels that are more efficient.

I don't, though, think that anyone could predict where they will be. I'll need to experiment.
 
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