The Offshore Voyaging Reference Site

Shorefasts And Line Reels on “Polaris”

A few months ago we published a photo essay about Polaris, the custom Hutting 54 especially designed and built for cruising remote places, owned by our friends Michael and Martina. Since then several people have asked about the line reels shown in the photographs. I passed these questions on to Michael and got the following answers.

Michael responds: The smaller reels aft on the pushpit were supplied by Easyroll and are loaded with 200 meters (256 feet) each of 10 mm (a little more than 3/8 inch) Dyneema, a high modulus rope much like Spectra, without any cover or sheath, with a break load of 10.5 metric tons (about 24,000 lb).

The larger custom-made reels are normally stowed in Polaris’s capacious forward locker and are swung out with a halyard to be installed in mounts on the deck when required. These reels carry an amazing 300 meters (984 feet) of 12 mm (about 1/2 inch) Dyneema with a break load of 16,000 metric tons (about 35,000 lb).

Dyneema has the advantages of floating and immense strength for its size and weight, as you can see from the above numbers. However, this material is not without some disadvantages:

  • The cost is eye popping, although savings of 50 to 70 percent over marine store pricing can be realized when you buy from an industrial source in volume.
  • It is susceptible to chafe to the point that Michael and Martina use larger diameter nylon or even chain to go around boulders on shore before connecting to the Dyneema.
  • The rope has very little stretch (on the order of 5% until breaking) and so the shorefast and boat will be subjected to substantial shock loads in anchorages that are exposed to any swell.
  • You can’t reliably knot this stuff, so each end must have a splice. (You can wrap it on a winch or cleat it off as long as you use a lot of turns.)

By now you might justifiably be wondering why Michael and Martina would go to all this trouble and expense for their shorefast system. This shot that Michael took just a couple of weeks ago should explain.

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Tim Good

For those of us that don’t want to invest in Dyneema what would you recommend for shore line and what diameter for say a 17t displacement boat?

Marc Dacey

As the owner of a 16T boat, I will follow this with interest, as it also has application in terms of attachment points for drogue bridles and stern anchors, I would think.

Eric Klem

Hi John,

I was just reading this post because it popped to the top of the comments and noticed that you mentioned chafe as a problem with the dyneema. I find this a little bit surprising and was wondering if you had any further thoughts on it. In the last few years, we have begun using dyneema in most high chafe applications on board because we have found it to be far superior. For example, our mooring pendants and snubber are both nylon but use a short piece of dyneema through our fairleads which are not as fair as I might like. Do you think that these issues were related to the small diameter or something else?

I have done a decent amount of shore tying in the PNW but that includes only a single tie and it has always been in something much stretchier. Having no real experience with dyneema in this application, my biggest theoretical concern would be shock loading although a 30′ piece of nylon cow hitched into the middle of the dyneema somewhere could probably eliminate this issue.

Eric

Marc Dacey

I look forward to that post, John, as I want to know how you make up a wire seize for a boulder…thimbles, bulldog clips, different lengths to lasso different-sized boulders? Sounds like an interesting topic. I wonder if you could do double-duty with wire bridles and “boulder-keepers”?

Eric Klem

Hi John,

Your point 3 makes a lot of sense provided that you have a minimum of a 3 point spread which allows you to really hold stationary with reasonable loads. When it comes to keeping boats in one place if compliance is necessary due to waves I often feel like we have figured out the spring part of a spring damper system but that we have not figured out the damper part. I suspect that this is why Colin’s drogue technique when anchored works so well. Your point about how this should never apply to shore fasts is well taken though.

Thanks.

Eric

Nick Kats

Also, rotate the boat in situ, so she faces wind and/or waves as appropriate.

One other thing. Spring lines. I learned this from reading about the British Navy, ca 1800. To bring cannon to bear as needed, eg on a moving target, a spring line was run from the anchor to the stern. Pulling in and/or letting out the anchor and/or spring line rotated the warship. I’ve used this technique with a line from mid chain to a stern cleat & it is effective.

Nick Kats

That last line should read ‘stern cleat’.

Bill Balme

John,

When in Finland last year, I saw several boats with reels and flat tape being used for shorelines. Thoughts on that as a solution? Certainly packs nicely on the reel…
Your post on shorelines is running late!!! 😉

Marc Dacey

No fear of that, John. Your readers keep pelting you with “but what if” questions!

aLBERTO DUHAU

Mine is more a question than a comment. I understand the spectra line is spliced and with this you tie a piece of steel cable that you wrap and tie around a rock. Now, with the other end, how do you tie it to the boat to avoid chafing and what do you do with the spare line as you adjust to the desired length of the shorefast, which must be always equal o less than the available line. Also how do you tie the SS cable to itself to make a loop that you can then tie up to the spectra or dymema line?

aLBERTO DUHAU

very clear! thanks