T&T: Swivel

[Candy Chapman and Gary Bell]

I mean no disrespect, and what follows is in no way a put down of 
anybody who uses an anchor swivel, but I just don't get it.  Why put a 
swivel between  your anchor and its rode?  I can't figure out what the 
purpose would be.  Even with an all chain rode do you expect to swing 
full circle enough times to bind up the chain in twists and 'flip' the 
anchor out of it's holding ground?  In that case perhaps a swivel could 
be placed well up the chain, about where you figure it would be well off 
the bottom.  If your rode is only partly chain, then the nylon rode will 
soak up most of the twisting, and if you plan to swing so much that it 
wouldn't, then perhaps a swivel could help at the upper end of the 
chain.  By its very nature, chain will bend to virtually any angle and 
retain nearly all its tensile strength, barring the aforementioned 
excessive twisting into knots.  If the rode is lifted enough to twist 
right next to the anchor I want the anchor to turn in the bottom and 
reset to the new direction of loading.  Clearly resetting anchors every 
time the tide or wind changes is not cool, and suggests to me that a 
better set or system is in order.  If there is even a modest lateral 
load routinely applied on the anchor stock you risk unsetting it.  If 
one is to be at anchor long enough for lots of twist to accumulate in a 
rode, why not put a swivel in the rode rather near the boat, as I 
believe is the practice with mooring buoys.  There it would be subject 
to virtually no side loading (shear like or bending), the difficulty I 
believe you were considering and the anchor and the portion of the rode 
lying on the bottom could rest in peace. 

Unless a lot of twisting is involved plain bare chain seems to me the 
very perfect swivel, able to bend any which way.  And, disregarding the 
fact that at the point where the anchor stock is pulled sideways it 
ought to be unsetting and resetting itsself, unless the bale on the 
anchor shackle is so tiny that the chain can bind up and put an 
inordinate side load on a single link or an undersized shackle, where's 
the problem?  The anchor bale certainly never runs through the windlass 
gypsy, so the largest one that would clear your deck gear seems the best 
to me. 

If you hoped that when the tide changed and you swung 90 or more degrees 
from your original position relative to the original anchor set, that 
the poor anchor stock would avoid all the bending moment of being drug 
around sideways wouldn't it end up in exactly the perfect orientation to 
be pulled up out of the bottom?   In addition I wouldn't want to trust 
everything to a primary anchor with a stock that 'might bend.' -- 
particularly if having that fragile stock is done in the name of a 
'lightweight anchor.'  My theory of anchoring includes using gravity (as 
well as digging shapes, rough surfaces and such) to hold the primary 
ground tackle on/in the ground -- and I am upgrading to the biggest 
Bruce I can personally lift (in case the windlass poops out) on 50 feet 
of chain and 300 feet of nylon.   I will have an additional weight (look 
up the term kellet) available to shackle to the upper end of the chain 
in crowded or windy anchorages and set the combination to have the 
kellet lie on the bottom at the upper end of the chain so that the boat 
pivots around the kellet in normal weather, leaving the anchor and chain 
undisturbed.  In heavy weather the weight of the kellet behaves like a 
whole bunch of extra chain rode, keeping the final part of the rode 
parallel to, and for the most part lying on the bottom and the anchor is 
kept in its best holding posture; even if it is called on to turn and 
reset in some new direction.  In light weather the boat swings around 
the kellet, not the anchor -- allowing a particularly short scope in a 
tight anchorage.  

Also consider using good sized stern anchors.  As I am blessed with a 
catamaran I can take particular advantage of a forward anchoring bridle 
which is round hitched to the nylon rode and controlled from each bow to 
adjust the boat's attitude to wind and waves.  I also plan to put a 
particularly large lightweight anchor (Fortress probably) aft, with 
minimal chain and a couple hundred feet of nylon rode.  I presently have 
a smaller Bruce on a chain and nylon rode from a smaller sailboat that 
serves this purpose very well.  The lightweight anchor and minimal 
chain, even with an additional kellet, is gracefully loaded into a 
dinghy, and is easily set from the dinghy in reasonable weather.   This 
will allow me to rather gracefully set a second anchor from the stern to 
entirely eliminate swinging in a tiny or a crowded anchorage.  We're not 
keen on either, but it could be needful on a steep foreshore or in a 
storm haven situation.  It more practically allows me to set a stern 
anchor to orient the boat to avoid adverse waves or winds.  In case my 
weather planning fails us, this stern anchor line can easily be fitted 
with a snubber and led forward to be shackled to the toerail to serve as 
a second or storm anchor.  In the unique case of a beachable catamaran 
like mine an aft windlass will be useful, so that we can set the aft 
anchor well off the beach, and then pay out rode as we run straight in 
(rather like Med mooring, except bow first), allowing us to later kedge 
off with the anchor instead of powering off with all that sand and 
gravel sucked off the beach into the cooling circuits, not to mention 
the risk of wanting to get off at a lower tide than when we beached. 

If I had a monohull ground tackle system to design, I think I would 
still go with a huge bow anchor; with a bunch of chain (all chain rode 
where the bottoms are intolerant of nylon); with a kellet or two of some 
sort; with a bridle long enough to be taken aft on one side; and with a 
lightweight Fortress type anchor aft, to be used wherever crowded 
anchorages, uncomfortable wind or waves, or long term holding would be 
issues.   I would give second priority to the stern anchor and then 
third priority to an additional bow anchor. 

Ah, you say, how about when my anchor is wedged into rocks or hooked 
under a cable?  Won't it get pulled from side to side enough to break 
swivels or twisted links/shackles?  Of course it will!  I very much 
favor little separate anchor floats, with a light stick at night, to 
give instant indication of drifting anchors, and to mark my ground 
tackle position so that hopefully nobody else sets across it.  I attach 
it to the anchor with a loop of seine twine through the big recovery 
shackle at the front of my anchor and tie it off to the little float so 
the marker buoy has as little scope as possible.  That way, if I ever 
have to recover a badly stuck anchor I can fetch the loop from the 
marker float, use it as a messenger to run a heavy line through the 
recovery shackle, and hopefully back it out.   I  can always reattach a 
marker float for diver recovery later if that doesn't work.  Throughout 
the PNW, the practice of rafting logs up and down our waterways for over 
a century, together with old shipbuilding and fisheries practices have 
left a  mess of chains, cables, sunk logs and timbers, etc. all over the 
bottom, so lost ground tackle is a real issue here.   That, and the 
volcanoes, of course.