Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 16-10-2021, 23:40   #1
Registered User

Join Date: Aug 2009
Location: Annapolis
Boat: S2-35C
Posts: 38
Difference between marine and auto winches

I am curious to the differences in pulling power between an auto winch vs an anchor windlass. Something just doesn't seem to add up.

Many auto winches, even low end ones advertise far more pulling power than the vast majority of anchor windlasses. This one is listed as having 30k pounds of pull, where as even the biggestMaxwell/Lowfrans etc are rated as no more than a couple thousand pounds of pull?


https://sherpa4x4.com/collections/fr...lb-truck-winch
pas63 is offline   Reply With Quote
Old 17-10-2021, 00:25   #2
Moderator
 
Jim Cate's Avatar

Join Date: May 2008
Location: cruising SW Pacific
Boat: Jon Sayer 1-off 46 ft fract rig sloop strip plank in W Red Cedar
Posts: 18,788
Re: Difference between marine and auto winches

I think the main differences are that the truck winches are very slow, don't have chain gypsies, are not salt water resistant and are reel type, not capable of passing chain down into a chain locker.

And the one you linked is kinda dear for a drum winch as well (not quite up to Yacht pricing, though)!

Jim
__________________
Jim and Ann s/v Insatiable II, hanging out in Port Cygnet for a while... spring is finally here (I think).
Jim Cate is online now   Reply With Quote
Old 17-10-2021, 01:48   #3
Registered User
 
chrisr's Avatar

Join Date: Dec 2016
Location: Australia
Boat: Tasman 40' catamaran
Posts: 1,619
Re: Difference between marine and auto winches

i think there might also be a matter of weight

the winch you mention weighs 30kg. our lewmar windlass weighs 9kg.

horses for courses ?

cheers,
__________________
"home is where the anchor drops"...back on lake mac to see family again as lockdowns being lifted... maintaining social distancing !
chrisr is offline   Reply With Quote
Old 17-10-2021, 01:53   #4
Registered User
 
Dave_S's Avatar

Join Date: Jun 2016
Location: Brisbane Australia
Boat: Schionning Waterline 1480
Posts: 1,736
Re: Difference between marine and auto winches

Yes, like Jim mentioned. Feet per minute, a 4x4 winch is around 10 fpm. On a boat with 300' out that's half an hour to retrieve and enough gearing mechanical advantage to sink your boat.
__________________
Regards
Dave
Dave_S is offline   Reply With Quote
Old 17-10-2021, 02:06   #5
Senior Cruiser
 
GordMay's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 43,853
Images: 241
Re: Difference between marine and auto winches

I’m pretty weak on mechanical theory, so the following will only begin to get us thinking about mechanical advantage.

Automotive recovery winches, and marine anchor windlass', despite both being pulling machines, are totally different animals. They utilize mechanical advantage in different ways.

For one thing, the reel on an automotive winch has a constantly changing diameter; whereas a marine windlass capstan [gypsy/wildcat] remains at a constant diameter.

As cable winds onto the Auto’ winch drum, the working diameter gets larger, and the less the winch's ability to pull because, the gearing is getting taller.

That is why the pulling power of an Auto’ winch is rated at the bottom [inner] layer of cable wrapped on the drum, not the top [outer] layers, where a lot of short pulls originate.

A winch only develops maximum power on the bottom [inner] layer, so each layer added after that point, as you spool in, reduces the available force, typically 8-15% per layer.

As a general rule of thumb, the second layer of cable, above the bottom, cuts the winch's rated pulling power by nearly 20 percent. Succeeding layers reduce effective pulling power by about 10 percent, per wrap.

That's why smart off-roaders often use a block, and all the cable [doubled]. The block doubles the pulling power, and doubling the cable [round the block & back] gets them to the inner layer, where the highest pulling power is.

All of this, also affects retrieval speed, independent of motor speed,, as others have noted.

None of this applies to a Marine windlass.

I’ll let the gearheads & mathematicians amplify/clarify this concept.
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 17-10-2021, 03:03   #6
Registered User

Join Date: Jan 2018
Boat: 50ft Custom Fast Catamaran
Posts: 5,408
Re: Difference between marine and auto winches

First, pulling power isn’t really how you use something to retrieve an anchor anyway.

All you are doing is pulling up some chain. I can do this with a manual winch on a 50ft, high windage catamaran with relative ease. Why? Because I’m just pulling chain up off the sea floor. In bad conditions (why are you going out in bad conditions?), I just motor slowly toward the anchor to make it easy to pull the chain up manually.

Ok, you are picturing that the anchor might be stuck at the end of pulling up the chain. Right? You don’t use the windlass for that either. After getting the rode all the way up and finding the anchor still stuck, You secure the anchor rode and push the boat gently forward with the engine popping it right out with ease. Then it’s a low power pull required to pull the free anchor up from the bottom.

So... these high ratings on the winch are not needed at all on a boat. You’re looking at the wrong attribute.
__________________
Epoxy can kill me like a kid smelling peanuts across the lunch room. Even the freshly machined dust from cured epoxy. Please donít suggest using it.
Chotu is offline   Reply With Quote
Old 17-10-2021, 05:11   #7
Registered User

Join Date: Dec 2010
Location: W Carib
Boat: Wildcat 35, Hobie 33
Posts: 13,144
Re: Difference between marine and auto winches

Ive installed and used both. Two different machines for different jobs.

Most of those differences are already mentioned.

An automotive/ATV winch would not be an ideal windlass because:

Its retrieval rate is comparatively very slow.

Its rated pull is many times more than needed.

Most are not salt water resistant.
belizesailor is offline   Reply With Quote
Old 17-10-2021, 05:31   #8
Registered User

Join Date: Oct 2019
Location: Kennebunk ME
Boat: Owner built 60í Aluminum Expedition Yacht.
Posts: 1,178
Re: Difference between marine and auto winches

All of the above reasons plus...how are you going to reinforce any place on your boat to withstand tons of force. S2 are well built, but they are not metal boats.
Warn, makes a 24 volt military version of their 4x4 winch. We tried one for our dinghy lift but itís not made to resist salt water or salt air. The mil-spec winch is somewhat more water resistant than the 4x4 version but the salt air will peel all the paint in short order then attack the motor. Kinda like a chain fall. Nice for lifting cannons or sunken cypress logs. Itís another fun tool for the manatee crew Itís not how we lift our anchor.
Happy trails to you.
Mark and his manatee crew
Manateeman is online now   Reply With Quote
Old 17-10-2021, 08:45   #9
Registered User
 
AndyEss's Avatar

Join Date: Dec 2016
Location: Sea of Cortez/northern Utah/ Wisconsin/ La Paz, BCS
Boat: Hans Christian 38 Mk II
Posts: 896
Images: 2
Re: Difference between marine and auto winches

One major difference between an auto winch and a marine anchor winch is that the auto winch drum is supported on both ends. An anchor winch is a capstan so you can get your chain over it at any place - but the capstan is supported only on one side. This cantilever is subject to 4 times the bending moment as compared to the nearly fixed double ends of an automotive drum winch.
A capstan is mechanically a pretty weak design, but its practicality for handling anchor chain makes it an ergonomically good choice..
AndyEss is offline   Reply With Quote
Old 17-10-2021, 09:18   #10
Registered User
 
Cheechako's Avatar

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 24,222
Re: Difference between marine and auto winches

Quote:
Originally Posted by AndyEss View Post
One major difference between an auto winch and a marine anchor winch is that the auto winch drum is supported on both ends. An anchor winch is a capstan so you can get your chain over it at any place - but the capstan is supported only on one side. This cantilever is subject to 4 times the bending moment as compared to the nearly fixed double ends of an automotive drum winch.
A capstan is mechanically a pretty weak design, but its practicality for handling anchor chain makes it an ergonomically good choice..
Yes, I think this is a big reason. It's an unsupported beam.

I'm not sure, but those auto winches probably don't have worm gearing either, rather maybe just simple spur gearing as they dont have to change 90 degrees from motor to capstan.?
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 17-10-2021, 10:07   #11
Registered User

Join Date: Jul 2020
Location: Wrangell Alaska
Boat: Beneteau Oceanis 38.1
Posts: 257
Re: Difference between marine and auto winches

Is a auto wrench designed to continuously pull? I thought those wrenches where for shorter bursts on smaller distances.
Sam Woodbridge is offline   Reply With Quote
Old 17-10-2021, 13:38   #12
Registered User
 
Cadence's Avatar

Join Date: Dec 2008
Location: SC
Boat: None,build the one shown of glass, had many from 6' to 48'.
Posts: 9,972
Re: Difference between marine and auto winches

It's apples and oranges!
Cadence is offline   Reply With Quote
Old 17-10-2021, 15:53   #13
Registered User

Join Date: Dec 2014
Posts: 619
Re: Difference between marine and auto winches

It is so simple. One is a marine product and the other ain't.
So for equivalent Newtons the marine item will be more expensive. It's all about the dollars.
billgewater is offline   Reply With Quote
Old 17-10-2021, 16:14   #14
Registered User

Join Date: Jul 2020
Location: Wrangell Alaska
Boat: Beneteau Oceanis 38.1
Posts: 257
Re: Difference between marine and auto winches

Bilgewater!

Re: Difference between marine and auto winches
It is so simple. One is a marine product and the other ain't.

Haha! So true and thank you.

Sam
Sam Woodbridge is offline   Reply With Quote
Old 17-10-2021, 16:41   #15
Registered User

Join Date: Jan 2019
Boat: Beneteau 432, C&C Landfall 42, Roberts Offshore 38
Posts: 3,151
Re: Difference between marine and auto winches

I don't get this discussion at all.....why on earth would anyone want to install an auto " winch" on their boat ??? There is absolutely zero benefit in attempting to do this, except comic relief from passing boat owners.
MicHughV is offline   Reply With Quote
Reply

Tags
enc, marine, winch

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Is there really a difference between marine and regular polyurethane? Bigjim Construction, Maintenance & Refit 15 23-07-2019 05:03
Difference between Anderson winches? sailingunity Deck hardware: Rigging, Sails & Hoisting 2 13-11-2017 23:29
Difference between marine watermarked and home reverse-osmosis systems ValiantV Plumbing Systems and Fixtures 20 11-04-2017 09:03
Difference Between Residential and Marine AC Circuit Panels ? albergsailor Electrical: Batteries, Generators & Solar 8 21-09-2011 12:56
Difference between fiberglass and glass covered wood multihulls skifinnatic Multihull Sailboats 5 04-06-2008 18:31

Advertise Here


All times are GMT -7. The time now is 21:38.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.