Olson 40 For Single Handed Blue Water Sailing

wsafm

Member
55
0
Carcrash - Can you send me or reply here as to the type of electric motor you installed. I recently pulled a dead perkins deisel out of my 40' and would like to go the same route you have gone. I am located in So Cal as well. 

 

Moonduster

Super Anarchist
4,823
231
The battery mentioned above is about 10kwh. Let's assume the battery to shaft is 90% efficient and the battery can be discharged to 80%, so there's about 7.2kwh getting to the prop.

A liter of diesel is about 5kwh and a normally aspirated diesel has around 33% thermal efficiency. Let's call it 25% at low RPM to get to the shaft.

So the battery is worth about 5.75 liters of diesel and a wild-ass guess of 6 knots for 4 hours with carefully selected prop. Note that the ISAF OSR for CAT 0, 1, 2, & 3 requires 8 hours motoring at 6 knots for the Olson 40's 36' LWL.

 
Last edited by a moderator:
The battery mentioned above is about 10kwh. Let's assume the battery to shaft is 90% efficient and the battery can be discharged to 80%, so there's about 7.2kwh getting to the prop.

A liter of diesel is about 5kwh and a normally aspirated diesel has around 33% thermal efficiency. Let's call it 25% at low RPM to get to the shaft.

So the battery is worth about 5.75 liters of diesel and a wild-ass guess of 6 knots for 4 hours with carefully selected prop. Note that the ISAF OSR for CAT 0, 1, 2, & 3 requires 8 hours motoring at 6 knots for the Olson 40's 36' LWL.
All true. But 100% irrelevant to me. I am glad others have different value systems. But there was absolutely nothing about the diesel that I liked, yet everything I did not like.

I don’t need any motor. This is purely a luxury to get in and out of a marina. No other use whatsoever.

Its cool that the boat is getting lighter. Nearly 800 lbs of useless, smelly, noisy, toxic shit removed from a 10,000 lb boat is noticeable.

 
I might charter a heavy, specially built boat to sail around the horn. But honestly, a boat that would work going around the horn easily is not the sort of boat I would like to own:

I like ventilation to stay cool when its hot. I like light boats that sail well. I like a cockpit where I feel the breeze. I like low enough freeboard so its easy to get in n out of a dinghy. I really like fin keels, not long keels that move the center of buoyancy down (increases rolling, decreases agility, but improves directional stability). I like dodgers that can be put away. I dont like metal boats.

But if I were to sail around the horn, I would want a heavy metal boat with a protected cockpit, hard dodger, insulation/heat, a big engine and a lot of fuel, and not much sail area. But that would be an awful boat in the places I like to be, where I like to sail, and how I like to sail.

Courses for horses.

 

ice9a

Member
412
8
including a trip around Cape Horn. 





 
how much do you know about the Cape (and Chile)?

From your posts in this thread I would guess not so very much.

There is a bunch written with good info . . . you might start with this http://www.bluewaterweb.com/p-54508-patagonia-tierra-del-fuego-nautical-gde-3rd-ed.aspx

And talk to several folks who have done it

You might decide that you don't want to do it after all after learning. We have some very experienced friends down there right now who are regretting it.  We tried to educate/warn them, but they were in the 'everyone else has done it, so we certainly can also' mode.

And if you decide you do still want to include it as part of the boat spec, you will also have learned what it entails/implies for the boat, which is not trivial.

There are really good skippers who have done crazy impressive things with crazy bad boats - just for example Matt Rutherford 27′ Albin-Vega and Webb on various boats - but they are perhaps not really very good examples for 'the rest of us'.

 

El Borracho

Verified User
6,833
2,790
Pacific Rim
seems like you could put together a water ballast setup with some tanks under the gunnels to get some righting moment back.
Hal Roth tried that on an SC50 for a singlehanded fiasco. Similar boat to O40. Utter failure I think. You can read all about it in his book. The ruined abomination of an SC50 is usually for sale somewhere.

 
All true. But 100% irrelevant to me. I am glad others have different value systems. But there was absolutely nothing about the diesel that I liked, yet everything I did not like.

I don’t need any motor. This is purely a luxury to get in and out of a marina. No other use whatsoever.

Its cool that the boat is getting lighter. Nearly 800 lbs of useless, smelly, noisy, toxic shit removed from a 10,000 lb boat is noticeable.
Crash,

My boat is down a few docks from you... I want to see your propulsion system when you get a chance. Looks cool.

Paul

 
Hal Roth tried that on an SC50 for a singlehanded fiasco. Similar boat to O40. Utter failure I think. You can read all about it in his book. The ruined abomination of an SC50 is usually for sale somewhere.
Can you give us the sparknotes version of why it was such a fiasco? Was it the water ballasts fault, the engineering behind it, or something else all together? 

~him

 

El Borracho

Verified User
6,833
2,790
Pacific Rim
Can you give us the sparknotes version of why it was such a fiasco? Was it the water ballasts fault, the engineering behind it, or something else all together? 

~him
The interior is dominated, ruined, by the huge tanks. So you can delete having a comfortable cruising boat from your list. Like living in a hallway.

Tacking is complicated. That should deter anyone.

Water ballasted hulls are best if beamy, SC50 is relatively narrow.

Maintenance nightmare. Yacht plumbing...ugh...those with experience will understand.

Hal picked the wrong boat, re-engineered, relative to the fleet leaders. He says so in the book.

An O-40 absolutely does not need water ballast or crew on the rail to sail just fine upwind or down. Of course don’t try to shorthand in a race against those that have a full crew. I go plenty fast upwind singlehanded (SC50). Typically under a #3 or #4 headsail and one reef. The full main and genoas are good for notoriously calm waters where all the heavy cruisers are motoring for days. Or any heading that allows a beam reach. First reef goes in at 10 TWS upwind. 

 

Foolish

Super Anarchist
1,734
408
Victoria, BC
One of the key points I made in my book is that the best boat for singlehanding is the boat you already own.  The second best boat is the one you're going to buy "next year".

Given that, having gone out some 1,200 times so far in my O30, and having researched the entire topic extensively for several years, I can tell you with assurance that if you are planning to buy a boat with singlehanding in mind, particularly on a difficult voyage like Cape Horn, then you should buy a boat designed for singlehanding.  There are only a few designs out there, so it is not a difficult task. And then if you have a specific budget in mind, the list becomes extremely small.  There a several Class 40s on the market for as little as $100k that would be perfect for this voyage.  https://www.yachtworld.com/boats/Sail/Racing+Sailboat/Class+40

Otherwise, as I said earlier the Figaro 2 is what I would consider to be the perfect boat for open ocean sailing. These boats are extremely tough, very fast, and reasonably comfortable. 

 
Its not 100% done yet, but the electric motor is working very well.

Its not done yet simply because I am no longer a young man, and there is only so much I can do each weekend. I went back to work for a bit -- offer too good to refuse -- and being in an office every day really consumes my energy. Making robots for space exploration is a lot of fun, but space is very hard: witness the failures and successes in space just this week.

Nothing at all has been difficult, expensive, time consuming. Today, I am tying down the batteries better, and finishing a few wire clamps, then its all done.

The surprising aspect was the remaining noise: the sound of the propeller spinning; the sound of the shaft turning in the shaft log. The motor itself is perhaps half as loud as the cooling fan in my laptop. Essentially silent. Turning the key causes a relay to be enabled, so there is a quiet click. Pushing the single control lever forward or back first causes a couple of clunks as the folding blades open, and then one hears the sound of the blades turning in the water and the sound of the shaft turning in the shaft log.

How loud is your propellor and shaft log? Its a weird question that I have never known before.

Getting in and out of the slip in the marina is fundamentally better: the motor does not stall ever, and I can control it perfectly smoothly from barely turning to 2000 rpms, instantly, reliably, repeatably. Exactly the right amount of thrust at any instant.

At 3.5 knots, which is a decent speed for cruising through the narrow parts of the marina, the motor consumes 330 watts.

2KW gets me going 5 knots. 5KW gets me going 6.2 knots, which is the same speed that the Yanmar 3GM30F achieved.

Smooth water, light air. If there was wind, we would of course be going faster with less power draw -- it is a sailboat!

One problem: the prop is poorly balanced. It is the original elliptical tip Martec from 1983, which is somewhat warn, with slightly sloppy blades. The lack of prop balance causes vibration at 1800+ rpms, which is over 5 knots. I basically do not exceed 4.5KW draw due to the prop vibration.

 

Alex W

Super Anarchist
3,346
322
Seattle, WA
Thanks for sharing the experience so far, especially the flat water speeds given power. Those numbers are much more useful than what most share. 

How large of a battery pack do you plan on, and in what chemistry?  

 
Right now it is 4 x 12v x 100Ah series LiFePO4 by Battle Born batteries in Reno. 5KWh.

By numbers, about the same as the 4 x 6v x 225Ah series-parallel 12v system I had before. But at discharge rates of the KW level, lead acid has about 5% effective capacity. So the lithium batteries give me about 20x range under power.

The charger refills an empty bank in 2 hours of shore power.

I have plenty of room to go to 10 or even 15KWh. The batteries are light and oddly inexpensive in boat bucks (or horse bucks or airplane bucks or employee payroll bucks) but of course crazy expensive in Starbucks. A headsail is about 5KWh of batteries, but the headsail prices go up as battery prices go down. 

Its recharge on the hook, instead of slip, that is keeping me from going bigger yet. So after I start installing solar, and testing the regen-via-prop-under-sail effectiveness, I may go bigger. It just seems silly to have more battery than I can charge. I might change my tune, we will see.

It is all a grand experiment.

 

Raz'r

Super Anarchist
63,114
5,842
De Nile
Right now it is 4 x 12v x 100Ah series LiFePO4 by Battle Born batteries in Reno. 5KWh.

By numbers, about the same as the 4 x 6v x 225Ah series-parallel 12v system I had before. But at discharge rates of the KW level, lead acid has about 5% effective capacity. So the lithium batteries give me about 20x range under power.

The charger refills an empty bank in 2 hours of shore power.

I have plenty of room to go to 10 or even 15KWh. The batteries are light and oddly inexpensive in boat bucks (or horse bucks or airplane bucks or employee payroll bucks) but of course crazy expensive in Starbucks. A headsail is about 5KWh of batteries, but the headsail prices go up as battery prices go down. 

Its recharge on the hook, instead of slip, that is keeping me from going bigger yet. So after I start installing solar, and testing the regen-via-prop-under-sail effectiveness, I may go bigger. It just seems silly to have more battery than I can charge. I might change my tune, we will see.

It is all a grand experiment.
Are you testing a Watt&Sea? Might be a good fit for a fast boat like yours.

 


Latest posts



Top