Mantus vs Rocna

[geem]

Just for fun i used the selection charts for Spade, Rocna and Mantus. My boat is 44ft and fully loaded, 41000lbs. The Spade comes out at 30kg, the Rocna at 33kg and the Mantus at 38kg. All fairly similar but the Mantus anchor is huge! Why does the Mantus need to be twice the size and 25% heavier than the Spade? I had a look at the Mantus in the local chandlers. The Mantus is way to big for its weight. I wouldnt want it on the bow when bashing into big seas. Also of relevance with anchor selection is how they stow on the roller. Friends with Rocnas have issues stowing theirs. One uses line and bungy. The other has a 14mm s/s pin through the anchor that snapped in some bouncy windward sailing! We have no such retention devices for our Spade. It just sits there and doesnt move. I have no idea how the Mantus stows but it does have a lot of area to catch a sea

 

[moomba]

Just for fun i used the selection charts for Spade, Rocna and Mantus. My boat is 44ft and fully loaded, 41000lbs. The Spade comes out at 30kg, the Rocna at 33kg and the Mantus at 38kg. All fairly similar but the Mantus anchor is huge! Why does the Mantus need to be twice the size and 25% heavier than the Spade? I had a look at the Mantus in the local chandlers. The Mantus is way to big for its weight. I wouldnt want it on the bow when bashing into big seas. Also of relevance with anchor selection is how they stow on the roller. Friends with Rocnas have issues stowing theirs. One uses line and bungy. The other has a 14mm s/s pin through the anchor that snapped in some bouncy windward sailing! We have no such retention devices for our Spade. It just sits there and doesnt move. I have no idea how the Mantus stows but it does have a lot of area to catch a sea

No issues storing my 25kg Rocna just sat were there used too be a Bruce 20kg , only issues was too drill a new hole in Rocna to put holding pin in.

 

[NormanS]

No issues storing my 25kg Rocna just sat were there used too be a Bruce 20kg , only issues was too drill a new hole in Rocna to put holding pin in.

Interesting that you felt that a 20kg Bruce had to be replaced by a 25kg Rocna.

 

[moomba]

Interesting that you felt that a 20kg Bruce had to be replaced by a 25kg Rocna.

Am heading over the horizon in a year or two , decided to. in my opinion upgrade the anchor to cope with more assortments of seabed and longer scope being played out, to that of the W of Scotland. Was an intresting information gathering and led to talking to several people in the industry including the MD of Knox anchors who suggested taking it up by 5kg.
The Bruce will stay as a spare

 

[geem]

No issues storing my 25kg Rocna just sat were there used too be a Bruce 20kg , only issues was too drill a new hole in Rocna to put holding pin in.

thats the point. We dont need to drill a hole in a Spade anchor. Its secure without and pin. The windlass holds it on the bow roller it doesnt move

 

[BelleSerene]

thats the point. We dont need to drill a hole in a Spade anchor. Its secure without and pin. The windlass holds it on the bow roller it doesnt move

Ditto my Rocna. (20kg, pre-Chinese manufacture fiasco, FWIW.)

Sits stably on Beneteau 39’ starboard bow roller. Has to be pushed forwards perhaps 20cm by foot or hand upon easing the chain on the windlass, before it’ll tip over the roller.

Incidentally, mine does have a hole in the shank for a pin. I’ve sometimes clipped a carabiner through there, tied to the pulpit, but really there’s no point.

 

[moomba]

Ditto my Rocna. (20kg, pre-Chinese manufacture fiasco, FWIW.)

Sits stably on Beneteau 39’ starboard bow roller. Has to be pushed forwards perhaps 20cm by foot or hand upon easing the chain on the windlass, before it’ll tip over the roller.

Incidentally, mine does have a hole in the shank for a pin. I’ve sometimes clipped a carabiner through there, tied to the pulpit, but really there’s no point.

Yes as my Rocna has a hole as well but does not line up with the pin hole on the windlass , seems hard too understand by Geem *45 but all it took was my cordless drill and a good drill piece and 2 minutes of my life, I appreciate that his spade does not need a new hole but I dnt get the point as was talking about a Bruce and a Rocna ,

 

[moomba]

thats the point. We dont need to drill a hole in a Spade anchor. Its secure without and pin. The windlass holds it on the bow roller it doesnt move

IF you chain windlass was to fail or the lock foot snapped were is your anchor going , when your 7 knots onto the wind
use a PIN or a rope to tie it off this is sensible

 

[RichardS]

I'm not sure what all this "hole drilling in anchors" is about. We just flip a chain lock down onto the chain when the chain is in or out and that's it.

Presumably those drilling holes don't have any fail-safe method of securing the anchor when the chain is extended but rely on a snubber?

Richard

 

[Neeves]

Should you not be away sailing? Anyway, happy hooking, and have a happy New Year (when it comes)

Thanks - and New Year was great, though a bit damp for anyone in Sydney

We were on the water from Boxing Day.

Does not everyone carry some sort of modern for mobile internet. We have coverage all the way from Sydney to Tasmania, down either the east or west coast (of Tas) and through Bass Strait. Coverage drops out for the SW coast, where no-body lives. Our modem has limited capacity - so hi-res images can be an issue - but we can always pay extra for more capacity if push comes to shove (being parsimonious images are not sent!.)

Our target is the SW coast of Las, specifically Port Davey, where we catch crayfish and abalone, climb the local hills Mount Misery and Rugby, walk to some of the other beaches , and pick up guests at the little airstrip. Like NW Scotland without midges. The only company are local bird watchers who monitor the endangered orange breasted parrots, who (the watchers) fly in to the airstrip stay a few days and fly out and a few visiting yachts.

Delightful - if you like that sort of thing.


Drilling a hole in a shank will reduce the integrity of the shank - you simply do not know what safety margin has been considered and thinking how shanks have been abused/ignored by anchor makers in the past it is not a practice we would ever consider. There are usually a couple of holes in the shank anyway - as suggested a carabiner seems a good idea. A chain lock is also another idea or a carabiner through the shackle with a strop lashed into the locker. There i really no need to drill through the shank.

Jonathan

 

[geem]

IF you chain windlass was to fail or the lock foot snapped were is your anchor going , when your 7 knots onto the wind
use a PIN or a rope to tie it off this is sensible

My windlass doesnt rely on a a lock foot what ever that is. It has a clutch thst tightens on the gipsy to lock it down. Done over 20,000 nm with this set up including a recent 1200 nm to windward. No problemo. No hole through anchor. No pin through anchor no lashing holding the anchor. The Spade just tightens up on the roller and doesnt move. Happy New Year!

 

[Neeves]

My windlass doesnt rely on a a lock foot what ever that is. It has a clutch thst tightens on the gipsy to lock it down. Done over 20,000 nm with this set up including a recent 1200 nm to windward. No problemo. No hole through anchor. No pin through anchor no lashing holding the anchor. The Spade just tightens up on the roller and doesnt move. Happy New Year!

There are couple, or more of related issues, on securing the anchor.

As mentioned drilling a hole in the shanks will compromise strength.

Leaving the anchor unsecured and reliant on a windlass clutch seems to be poor seamanship. Having no back up to a snubber being used primarily for its elasticity, again seems poor seamanship.

But everyone to their own - we, or at least I, am guilty of poor seamanship on many occasions, I try not to advertise my inadequacies.

Snubbers used for their elasticity to dampen any snatch loads are consumables. If they are sized correctly they will fail, unless you schedule replacements. When they fail, unless you have another snubber, the full snatch load will be on the windlass - so have a back stop, chain lock has been mentioned. But a short strop (attached to a strong point) with a chain hook will suffice. But you really don't want snatch loads imposed on the windlass

Retreiving the anchor tight against the bow roller and assuming the clutch will hold it (it might, or not) means the windlass is under constant and unnecessary tension. Having a chain lock, lashing the anchor, using that short strop above, means you can reduce the tension on the windlass. Of course if you are made of money none of this matters, when you lose the anchor or the windlass fails you can always buy another one. I recall a member here lost all of his rode, including a Spade when on passage from the UK to the Med (I think off The Needles) - when whatever he was using the rode failed - and he lost the lot.

We use a short dyneema strop with a claw attached to the chain about 200mm back from the shackle. We ue the same arrangement a backup to our bridle. When we are long passage we also lash the anchor to stop it wobbling (and wearing) the bow roller (so belt and braces).

Jonathan

 

[Neeves]

Just for fun i used the selection charts for Spade, Rocna and Mantus. My boat is 44ft and fully loaded, 41000lbs. The Spade comes out at 30kg, the Rocna at 33kg and the Mantus at 38kg. All fairly similar but the Mantus anchor is huge! Why does the Mantus need to be twice the size and 25% heavier than the Spade? I had a look at the Mantus in the local chandlers. The Mantus is way to big for its weight. I wouldnt want it on the bow when bashing into big seas. Also of relevance with anchor selection is how they stow on the roller. Friends with Rocnas have issues stowing theirs. One uses line and bungy. The other has a 14mm s/s pin through the anchor that snapped in some bouncy windward sailing! We have no such retention devices for our Spade. It just sits there and doesnt move. I have no idea how the Mantus stows but it does have a lot of area to catch a sea

I have to agree about the size of the fluke of some anchors - people appear to lack confidence and/or make the wrong choices.

We have a 38' cat. The bridge deck clearance is 1m, that's the distance from the underside of the cabin to sealevel. We then have full headroom within the cabin - so our cabin roof is about 3m above sealevel. Our bow roller is 1m above sealevel. We often have seas over the bow and a large anchor would imply slow us down and we occasionally have seas breaking right over the cabin roof. When we raced our X-Yacht, notoriously wet yachts, sitting on side was always wet.

Any huge fluke is going to catch seas - better to have an anchor you can remove (think alloy) or one where you rely on design to give hold not imply rely on surface area.

When I read of people advocating taking the anchor manufacturer's advise and going 2 sizes bigger I really have to wonder. Why chose an anchor from someone whose recommendation you are going to ignore - there is a total lack of confidence somewhere in the equation. I also wonder about those recommending going 2 sizes, or more, bigger - do they ever make sea or ocean passages.

A case in point is Mantus. A 50kg Mantus will have a similar hold to approximately a 25kg Spade or Rocna. Why buy a poorly designed Mantus when a better design will result in approximately half the weight and a significant reduction in area.

Jonathan

 

[BelleSerene]

IF you chain windlass was to fail or the lock foot snapped were is your anchor going , when your 7 knots onto the wind
use a PIN or a rope to tie it off this is sensible

Wot?

Happy new year, anyway.

 

[Seven Spades]

Back on track, can anyone comment on the merits of a Rocna VS a Spade. My last boat had Rocna and I trusted it. My new boat has a Spade. I am not sure which is better, I worried about something jamming in the loop of the Rocna and I would think that it is another part of the anchor that could get snagged in coral. the Spade does not have the loop but no one really talks about them, has VYV seen bent Spades? Do they re-set as well as a Rocna and which has the highest holding power?

 

[geem]

There are couple, or more of related issues, on securing the anchor.

As mentioned drilling a hole in the shanks will compromise strength.

Leaving the anchor unsecured and reliant on a windlass clutch seems to be poor seamanship. Having no back up to a snubber being used primarily for its elasticity, again seems poor seamanship.

But everyone to their own - we, or at least I, am guilty of poor seamanship on many occasions, I try not to advertise my inadequacies.

Snubbers used for their elasticity to dampen any snatch loads are consumables. If they are sized correctly they will fail, unless you schedule replacements. When they fail, unless you have another snubber, the full snatch load will be on the windlass - so have a back stop, chain lock has been mentioned. But a short strop (attached to a strong point) with a chain hook will suffice. But you really don't want snatch loads imposed on the windlass

Retreiving the anchor tight against the bow roller and assuming the clutch will hold it (it might, or not) means the windlass is under constant and unnecessary tension. Having a chain lock, lashing the anchor, using that short strop above, means you can reduce the tension on the windlass. Of course if you are made of money none of this matters, when you lose the anchor or the windlass fails you can always buy another one. I recall a member here lost all of his rode, including a Spade when on passage from the UK to the Med (I think off The Needles) - when whatever he was using the rode failed - and he lost the lot.

We use a short dyneema strop with a claw attached to the chain about 200mm back from the shackle. We ue the same arrangement a backup to our bridle. When we are long passage we also lash the anchor to stop it wobbling (and wearing) the bow roller (so belt and braces).

Jonathan

There is no load on the windlass if you are using the clutch. It simply locks the chain to the locked gipsy. Look at the spec of a Lofrans Falkon. You can do this with a slightly slack or tight chain. The locked gipsy doesnt have any consequences for the gearbox in the windlass. You may consider this bad seamanship but I don't. Its a conscious decision that works better than a bit of string or bungy.
Our bow rollers are 316s/s. They domt wear like a nylon roller.

 

[vyv_cox]

Back on track, can anyone comment on the merits of a Rocna VS a Spade. My last boat had Rocna and I trusted it. My new boat has a Spade. I am not sure which is better, I worried about something jamming in the loop of the Rocna and I would think that it is another part of the anchor that could get snagged in coral. the Spade does not have the loop but no one really talks about them, has VYV seen bent Spades? Do they re-set as well as a Rocna and which has the highest holding power?

I have not seen a bent Spade shank and imagine that their construction must make this one of the strongest shanks on the market. Resetting does seem to be effective. In the 2006 tests by West/YM/Sail the Spade holding power was highest of all. Several other tests show similar. My view is that this is the easiest parameter to measure but does not tell us a lot in comparing similar designs. It does show up the major deficiency of non concave designs but again, these are probably good enough for most users.

 

[Neeves]

The gypsy, at least on the windlass I know of, is attached to the shaft of the windlass, lock the gypsy and tension the chain and you load the windlass. If the clutch is set sufficiently well then excess load will release the gypsy. If you think the gearbox indestructible then forget the gearbox - think of the bolts securing the windlass, think of the structure to which the windlass is bolted

I have measured snatch loads of 650kg - and then chickened out - Its your choice whether you rely on your gypsy taking snatch loads or whether you rely on string (though I have never heard of anyone calling dyneema 'string'). No-one in their right mind would rely on bungy - there is simply not enough 'room' for a bungy to extend.

If your bow rollers (the roller itself) are 316, excellent, most I see are some form of polymer, ours included, though I do see the occasional one made from bronze (or something similar). I would conclude that most high volume production yachts rely on polymer - because it is cheaper than stainless (or some non ferrous material).

Jonathan

 

[Neeves]

We use a Spade regularly.

I have seen a bent (shank) Spade, caught in rock and aggressively retrieved (but I have seen a bent Rocna, toe, for the same reasons - and I would have said (before seeing the bent toe) that a Rocna toe was indestructible). Basically you can bend any metal if you try hard enough.

Spade carries, picks up, less mud than Rocna - so if you have used a Rocna in the past then Spade will need less cleaning (in sand no difference - both are self cleaning). In weed I would say, very subjective, Spade is better (better concentration of ballast as well as less opportunity to clog between fluke and roll bar). But if you do not anchor in weed then this is not an issue.

Personally we carry a Spade, but ours is alloy, and we would not replace it with a Rocna. We use a convex Excel as our primary on our bow roller also alloy - both are 8kg. We also carry and FX 16, set for sand and an FX 37 set for mud.

We carry an alloy Spade because we think it is better - and we have an equally sized (both X80) stainless Spade which we do not use, except for tests. The stainless Spade sits lonely and unloved in my workshop along with other anchors I would not use, 15kg Mantus, 20kg Manson plough, FX16 and a variety of smaller models ( 2 x Rocna, Supreme, 2 xTern, Ray, 2 x CQRs, Fishermans, Spade, Excel etc.

Jonathan

 

[GHA]

Back on track, can anyone comment on the merits of a Rocna VS a Spade. My last boat had Rocna and I trusted it. My new boat has a Spade. I am not sure which is better, I worried about something jamming in the loop of the Rocna and I would think that it is another part of the anchor that could get snagged in coral. the Spade does not have the loop but no one really talks about them, has VYV seen bent Spades? Do they re-set as well as a Rocna and which has the highest holding power?

Have one of each onboard, blindfolded very much doubt if you could tell them apart, both are great.