Mail: posidonia@posidonia.com

MCMV

LOW MAGNETIC PERMEABILITY EQUIPMENT FOR MCMV

Having had a long experience in the shipping industry for more than 80 years , Posidonia is also becoming well known for the special equipment  that must be installed on mine countermeasure vessels (MCMV) such as minesweepers, minehunters or drones.
All the equipment has to be as light as possible and have low magnetic permeability, but keep a high performance.
Posidonia is a leader in welded anchors and chains, reducing the weight on board by offering:

- Super High Holding Power anchors (PTW+ ®)

- Chains  in high tensile steel Grade 3

Both in low magnetic permeability steel: a unique combination fully approved by shipping classification registers.
Low magnetic permeability has not to be confused with magnetism.
It is the measure of the ability of a material to support the formation of a magnetic field within itself , typically represented by the (italicized) Greek letter µ (*).
The most common material that complies to the above is  generally AISI 316L  or 304L, 
but it doesn’t  exist in GRADE 3!.

After  several years of  R&D  Posidonia  identified new materials, with a special manufacturing process  to  achieve GRADE 3 chains  keeping a very low magnetic permeability.
Several years ago the average magnetic permeability value was fixed at µ < 2,0, nowadays  the average required value is approx. µ < 1,38.

We are now able to supply  chains µ < 1,00 and anchors µ < 1,09

 

A medium/small MCMV with an average equipment number between 240-280 needs to be equipped with:

Option A (Grade 2 + HHP)

12 lengths 27,5 meters stud link anchor chain, diameter 24 mm. grade 2
breaking load kN 332 - proof load kN 237
Total weight:  4260 Kg
Total volume : 2,136 m3

1 high holding power anchor Kg 585

Total  weight, anchor chains and fittings : 4887 Kg

Option B (Grade 3 + SHHP)

12 lengths 27,5 meters stud link anchor chain, diameter 22 mm. grade 3
breaking load kN 401 - proof load kN 280
Total weight:  3528 Kg
Total volume : 1,764 m3

1 Super high holding power anchor Kg 390

Total  weight, anchor chains and fittings : 3958 Kg


The difference of weight between Option A and Option B is approx. 20% less and for higher equipment numbers even more.

* µ=µr µ0   (µr  relative permeability)  (µ0  permeability of free space)