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Old 04-17-2018, 07:21 AM   #1
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Anchor over the bow roller

I was bringing the anchor in last time we were out - not thinking of anything in particular until the anchor chain brought the tip of the anchor shank to the bow roller. At this point the chain is pulling at right angles to the shank and has to pull the anchor (25kg) through 90 degrees (from vertical to horizontal) to get it on board. The winch manages it but it dawned on me what a horrendous strain it must put on the motor and gearbox. Initially the leverage the winch has to work with is virtually nil but it is expected to lift it.

The only thing I could think of was a second roller, forward and down from the existing bow roller which might reduce the angle of direction change from 90degrees to perhaps 45degrees

Am I overthinking this or should I just leave the winch to get on with winching?
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Old 04-17-2018, 07:24 AM   #2
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they make roller assemblies that do that in various ways for various anchors.
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Old 04-17-2018, 07:38 AM   #3
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Doesn't your roller dip forward to meet the shank and them come up horizontally with the shank to reduce the stress?
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Old 04-17-2018, 08:22 AM   #4
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We lift the shank manually.

Another reason is that if I used the winch to do it, the flukes would launch north, bash the underside of our slotted pulpit... whereas I can control speed when I lift it that last little bit myself.

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Old 04-17-2018, 08:36 AM   #5
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I stop my winch just as the shank starts over the roller and points skyward. Then I just bump the motor an inch or two at a time with pauses until the shank flops over and down.

The strain on the motor during that time not a big deal - the "weight" of pulling the anchor around a corner with the axis of rotation at about the halfway point of its length is minimal - Torque and Equilibrium
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Old 04-17-2018, 08:53 AM   #6
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Lewmar Makes one that helps turn the corner it does minimize the stress but does not eliminate it
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Old 04-17-2018, 08:57 AM   #7
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Originally Posted by siestakey View Post
Lewmar Makes one that helps turn the corner it does minimize the stress but does not eliminate it
Anchorlift makes something similiar that turns the anchor and looks like it would ease the stress. Alas, it won't work on our boat because our windless is too far forward
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Old 04-17-2018, 09:00 AM   #8
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https://www.mauriprosailing.com/us/p...caAnkkEALw_wcB
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Old 04-17-2018, 09:24 AM   #9
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Seems to me the forces would be very large. The very end of the anchor shank is a short lever pulling the heavy end of the anchor through a 90 degree arc fairly quickly.

This creates a lot of strain on the connection point. If a swivel is used, and the anchor is sideways as the swivel passes over the roller, a bending force is imparted on the swivel. Swivels are designed to be strong in tension - a straight pull when anchor and chain aligned. Not sure how strong a swivel is when it is being bent sideways.

There is a debate about the usefulness of swivels and their real working load strength. I decided to get rid of mine and now connect the anchor with a safety wired shackle.

When the anchor reaches the roller I very carefully inch the shank over the roller, minimizing the big "flip up" as the shank gets horizontal. Have not had any issues with twisted chain. Works for me.
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Old 04-17-2018, 11:22 AM   #10
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The forces are not all that big compared to what happens when you lift a couple of hundred of feet of chain plus the anchor off the ground. Anchoring in deep water is common here in the PNW.

Lets do a back of the envelope calculation. Say the winch has just raised the anchor to the roller and your anchor is hanging straight down. Which means the anchor's lever arm is zero and the pull the winch sees is just the weight of the anchor. As you raise the anchor further, the center of gravity of the anchor is moving out away from the boat to rotate around the roller. At 45 degrees, your anchor lever arm would be say 10 inches and your winch lever arm say 2 inches. In this case the pull on the winch would be 5 times your anchor weight- not a big deal compared to raising your anchor from the bottom.
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Old 04-18-2018, 01:23 AM   #11
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Hi,

Anchorlift™ CX help your broblem!

https://www.anchorlift.com/bow-rollers/

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Or



or "twist"


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Old 04-18-2018, 04:00 AM   #12
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I say let the windlass get on with its job. I`m more worried it will retrieve too strongly and jerk the anchor to a stop. Wouldn`t it have more load once the anchor comes off the bottom? (My Muir has a 1200watt replacement motor).
It could relate to the design of the end of the shank of your anchor. If it is square, or otherwise gets caught at the roller there could be an issue. Ours comes on board easily.My roller axle has a grease nipple(easy tiger!) or zerk, to grease it.
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Old 04-18-2018, 05:09 AM   #13
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My old, dying windlass would struggle to get the anchor up from the bottom even when it had been liberated from the sand/mud and there was only 5-6metres of vertical chain to lift. Then when the anchor shank was at the bow roller it simply would not come over.

The new Muir windlass would lift the anchor and haul it up, but the clutch would slip when the anchor shank was at the roller. So the force required to get the anchor over the roller is the greatest load i have seen to date with the new windlass. But I have not anchored in dee water yet. Now I have the clutch tight enough to avoid slippage when hauling, but can still get some slippage when backing down to set the anchor. I'm fine with that. But always set the snubber!

When hauling anchor I think momentum helps. My chain counter starts beeping when there is 1.6m of chain to go, so I am ready to let the switch go. But I like to keep it running continuously to get the shank up over the roller. I think that bumping on/off for an inch or so at a time would stress everything to a much higher extent.
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Old 04-18-2018, 06:17 AM   #14
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Our 150lber comes up and over 90degrees.
Never a problem doing the lift , no hint of strain but we have cheap yellow nylon rope woven through the last meter of chain so we can see it coming and then pulse it up and over as mentioned by an earlier poster.

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Old 04-18-2018, 08:11 AM   #15
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Quote:
Originally Posted by Brisyboy View Post
I was bringing the anchor in last time we were out - not thinking of anything in particular until the anchor chain brought the tip of the anchor shank to the bow roller. At this point the chain is pulling at right angles to the shank and has to pull the anchor (25kg) through 90 degrees (from vertical to horizontal) to get it on board. The winch manages it but it dawned on me what a horrendous strain it must put on the motor and gearbox. Initially the leverage the winch has to work with is virtually nil but it is expected to lift it.

The only thing I could think of was a second roller, forward and down from the existing bow roller which might reduce the angle of direction change from 90degrees to perhaps 45degrees

Am I overthinking this or should I just leave the winch to get on with winching?
Brisyboy, as the others have said, it is probably not a huge issue, but one I also felt worth addressing when I bought my Sarca. Although I did not buy the purpose built Sarca roller assembly, the hinged set I did buy is very like it, (only actually a bit better I think, as the hinged part is longer), and the hinged section, that revolves up under the anchor as she comes over, definitely does reduce that load. Probably does lengthen the life of the windlass motor & gears somewhat I'd think. These are available at most chandleries, I think. Also, you might be able to see I was lucky enough to be able to fit it inside the old existing single bronze roller system, now painted white. One mounting bolt slipped neatly into where the bronze roller was mounted. I pull her in so the shank is horizontal when on the move, of course. See pics of mine.
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Old 04-18-2018, 08:31 AM   #16
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Our Vulcan anchor has a curved shank which seems to be easier to pull up that last little bit as compared to the straight shank anchor it replaced. But as noted by others, the real test of a windlass and its wiring is from a deep hard set.

Also, I will at times use a boat hook to rotate the anchor for a nice final pull over the roller. Easy enough to do with a proper made swivel.
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Old 04-19-2018, 10:57 PM   #17
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Larger bow rollers are dual roller or have a pivoting anchor cradle. Mine has dual rollers and lifts a 200# anchor w/o noticeable problems.
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Old 04-20-2018, 02:24 AM   #18
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Be gentle. Bring the anchor slowly (short "ups") the last few feet.
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Old 04-20-2018, 06:55 AM   #19
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Originally Posted by sunchaser View Post
Our Vulcan anchor has a curved shank which seems to be easier to pull up that last little bit as compared to the straight shank anchor it replaced. But as noted by others, the real test of a windlass and its wiring is from a deep hard set.

Also, I will at times use a boat hook to rotate the anchor for a nice final pull over the roller. Easy enough to do with a proper made swivel.

There's a number of other anchors that have the curved shank for a very different reason. Manson Boss, Spade, .....
On second thought I looked at other anchors and see that the curve like on the above named anchors is in the wrong place. To help going over the roller innitially the curve would need to be at the end of the shank where the rode attaches. The Vulcan may be curved there but the others are not. Does the curve go to the very end of the shank Sunchaser?

I pull my smallish anchors over the rail aft of the bow roller and store them on deck or belowdecks.
On anchors that I carry on the bow roller I pull them over the roller by hand and hold my hand high so the angle in question is only 45 degrees or so.

Another thought on this is that the longer the shank is the bigger the problem.
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Old 04-20-2018, 07:58 AM   #20
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You guys may want to consider the cost of a new windlass long term versus losing your back. Be careful.
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