Anchor Swivels

[KellysEye]

>Do you have any links or analysis you can share?

There are no links. In the Med the water is crystal clear so it is easy to look at what is on the bottom, a yacht I know spotted the broken swivels and passed it on. It was the same charter company but he didn't say what it was, the bigggest charter company is Sunsail. The charter company involved would have bought the same swivels.

 

[noelex]

BTW Titan marine have recently released a flip swivel designed specifically for Rocna anchors (but I presume it will work with many other brands).

I not seen one so I have no idea if it is any good.

It looks like it works in a similar way to the Ultra flip swivel, but without the ball and socket joint.Titan claim it is tested to exceed the working load and breaking strength of the G40 chain in a straight pull and importantly will also do this with a side load.

There are 5 models suitable for anchors from 9-40kg. It is stainless steel. The grade is not specified but is claimed to be stronger and more corrosion resistant than 316, so it is perhaps one of the duplex stainless steels.

Hopefully it will be less expensive than the Ultra flip swivel.

 

[Neeves]

Peter Smith has had ambitions to introduce a swivel or flip swivel for years, at least from around a decade ago (the earliest reference I know of is 2007).. An early idea was one designed similar to the one from Oscalutti - viz a bent link (or Boomerang) but with a swivel on the end. I was never sure of the reasoning behind this sort of design as the Boomerang self rights the anchor and seems to negate the need for a swivel.

The swivel mechanism then was simply a shaft, I think it was actually a stud with a 'U' bolt 'device' simply attached to the stud and retained with a nut on the threaded end of the stud. I assume the nut would be welded in. There was thus no sophisticated bearing surface.

This type of 'bearing' is very common in many swivels.

The original intent was to assemble from 2205 Duplex components - this would be very uncommon - but desirable as Duplex steel can have a tensile strength of 0ver 600 MPa.

Not much of this design appears to have been used in the new swivel - but it might indicate the type of assembly, how the 'bearing' is designed and the type of steel (all of which are worth checking before purchase).

The new swivel looks as if it copies from the Ultra and attaches direct to the shank. If it is designed for the Rocna anchor and is size specific it may not fit on other anchors as the shackle slot on the Rocna will be different to other anchors and with different spacings the shank may simply not fit into the recess of the Rocna swivel nor match the location of the retaining pin. These flip swivels, including the Ultra, lengthen the shank of the anchor, increasing the lever force - and it is unlikely all anchors are designed with this in mind (you might bend your shank end). if you are interested, in either the Ultra or Rocna flip swivel check that it fits before you buy - and be cognisant that your shank end may not be designed to take the extra tension.

Jonathan