Frequently Asked Questions

Frequently Asked Questions for SMM Products


Frequently Asked Questions for SMM products
Steel Coils Loading Frequently Asked Questions

Is There Any Version of Steel Coils Loading Software for Non-CSR vessel?

There is a version that was created by our company in 1997 and was used for Non-CSR vessels.  However, it is to our recommendation to use the version for CSR Vessels for the reasons that are summarized below: 

The CSR Method (2010) given the fact that is adopted by ALL IACS MEMBERS provides our software wide acceptance.  These requirements (plate thickness & Longitudinal Stiffeners Section Modulus) may be equally applied to Non-CSR Vessels from local strength point of view.

To counter act the possible conservative nature of steel coil Rules in general, within Steel Coils Loading software, three (3) characteristics have been built-in.

- If the tank top is in excellent condition, then corrosion margin required by CSR is reduced to a minimum in agreement with the Client.

- Apart from the software itself, a Steel Coils Loading Booklet can, optionally, be provided where BOTH with and without corrosion/wastage margin Maximum Allowable No. of Tiers appear.

- Finally, the Actual Steel Coils Loading Module of the program provides the freedom to the Ship Operator to evaluate previous Steel Coils Loading Conditions and to decide what is the Maximum Allowable percentage for each Cargo Hold, of a particular vessel.

Can Steel Coils Loading Software Consider About Loading With Key Coil And Judge Based On The Position Of The Key Coil?

Key Coil Factor is taken into consideration in the CSR version of Steel Soils Loading Software, as per CSR (2010).

Can Steel Coils Loading Software Consider About Loading With Key Coil And Judge Based On The Position Of The Key Coil?

Key Coil Factor is taken into consideration in the CSR version of Steel Soils Loading Software, as per CSR (2010).

Does The Steel Coils Loading Software Have Class Approval?

In Steel Coils Loading software, all the algorithms are followed based on the CSR-2010 (Common Structural Rules), which consist of the most common method for such calculation adopted by all IACS Members, hence when required Class Approval of certain loading conditions, no delays or complications are noticed during the Approval.

Classification Societies customarily can review and approve any practical coil size, so it is preferable to approve on a case by case basis.

Is the Official Use Of Steel Coils Loading Software Kind Of Evidence For Regulation Compliant Loading Of Steel Coils?

As per our experience with IACS members, our software, generally, is in line with Class requirements. 

Practically, whenever there is need for a particular coil size the final OK by Class, the software printout may be submitted for the particular case. 

It is certain that following the program results, any deformation or local strength damage will not be noticed.

Does The CSR Version Of Steel Coils Loading Software Calculate With Corrosion Margin?

The corrosion margin is mandatory in CSR version. However in the manual, both results (Number of Tiers) with and without such margin are shown.

Steel Coils Loading its Challenges and ways to overcome

The loads derived from steel coils loading are very concentrated, leading to higher stresses in the double bottom than would be expected. Calculation of steel coils loading conditions, which reflect actual loading is essential to maintain the required level of safety.

Loading manuals of many ships used in the steel trade that carry coils, contain limited information:

either

The Max. Tank Top Strength (MT/m2) for uniform loading which however is not advisable criterion for Steel Coils Loading.

or

In the cases where there is some information from the Builders in the Loading Manual, this is usually the bare minimum, e.g. Covers only the case of 2 Tiers of 15t coils, supported by 3 rows of dunnage.

 

Most operators have adopted the following calculation formula of maximum tonnage per hold on the basis of:

[area of tank top (m2) x permissible loading tonnes per m2] 

Whilst this is the correct calculation when dealing with homogeneous bulk cargoes, which exert a uniform load on the tanktop, it is incorrect for steel coils because the load, which they exert, is not uniform. The crossing point of the coils and the dunnage will give rise to a point load on the double bottom structure. This loading is very different from the uniform loading and will give rise to higher stresses in the tanktop plating as well as the inner bottom longitudinals.

 

The dominant regulations are CSR-2010 (Common Structural Rules), which consist of the most common method for such calculation adopted by all IACS Members. Nonetheless, the non-CSR built vessels may be regulated by other Class-specific Rules, which do not consider wastage factor in the relevant calculations. 

Generally, Class requirements could be considered conservative, as the spirit of the Class requirement is based on the fact that the calculation depends on the worst relative position of coils to the ship’s floors. In this respect, the actual Loading of Coils on the entire Tank Top Area may or may not reach the maximum stresses, as allowed by the Regulation.