Anchor Certification, HHP & SHHP Classification, and Type Approval

Lloyd’s, RINA, et al

International classification societies offer classification of marine anchors, which in turn tends to be advertised by anchor manufacturers. Phrases such as “HHP”, “SHHP”, and “type approval” are in common usage. Informative summaries of what these classifications actually mean tend to be in short supply.

Manufacturers may imply these standards mean much more than they actually do. Advertising the apparent endorsement of a well known and respected organization can be of considerable value, particularly to a market which is not familiar with the precise regulations. But too much focus on this is very misleading.

So what does it all actually mean?

RINA and Lloyd’s logos

The Classification Societies

There a number of various societies around the world, some specialist in the marine industry. Preferences generally depend on location, and most societies are very old and have considerable tradition behind them.

• RINA (Registro Italiano Navale) is Italian, preferred in Italy and Europe, also widely used worldwide.
• Lloyd’s Register is based in London and is popular in the UK and many Commonwealth countries. Not to be confused with Lloyd’s of London (insurance) or Lloyds Bank!
• Bureau Veritas is French but widely renowned throughout Europe and the rest of the world.
• ABS (American Bureau of Shipping) is American.
• DNV (Det Norske Veritas) is Norwegian.

Generally there is equivalence between the various societies, and anchor classification rules are almost identical. Standards as defined by the regulations from different societies are interchangeable. One society will give their approval based on the existing approval of another – without any, or perhaps with reduced, inspection of their own. For the purpose of this article, the following explanations apply to all societies.

Type Approval

Type approval is an abstract endorsement by the society of the anchor’s design, or “type”. A fee is charged by the society which then inspects the manufacturer’s production drawings. They then either approve the design, or request modifications. This inspection makes no comment with regard to the actual effectiveness of the anchor.

Society rules and regulations supply very little information on the criteria and technical requirements for any given type. It is assumed on the basis of the society’s reputation that their inspecting engineers are capable and professional.

Type approval is therefore a nice stamp of approval on the anchor’s design, but it generally does not mean much in practice. Any anchor that would fail this process would not last long in the face of independent testing and feedback from demanding boaters.

Seabed Testing: HHP and SHHP

Above: Standard stockless anchor used as a benchmark for HHP and SHHP pull testing.

Above and below: Pull testing is typically conducted using a powerful motorboat such as a tug, under the control and supervision of the society inspector who measures the anchors’ performance with a sophisticated load-cell.

HHP (High Holding Power) is a classification offered by all societies, and has been around for a long time. Lloyd’s Register, RINA, and DNV also offer the more recently introduced upgraded classification of SHHP (Super High Holding Power). (SHHP was initially called VHHP – the V for “Very” – by some societies before standardization occurred, and this reference may be found in some outdated literature and on older anchors.)

HHP and SHHP are both performance standards that relate to the efficiency of the anchor in straight line pulls (pure resistance performance). Sample anchors are tested against a “standard stockless anchor”, such as a Hall or “Navy” type, of similar size and generally over multiple seabed types. The standards are defined as follows:

HHP:

The anchor must hold at least twice that of a standard stockless anchor of the same mass.

SHHP:

Four times that of a standard stockless anchor, or twice that of a previously approved HHP anchor.

Neither is a particularly high standard. A “standard stockless anchor” is extraordinarily inefficient when compared to other types on a weight-for-weight basis, and independent tests show a number of modern anchors capable of exceeding even SHHP. That said, SHHP does distinguish older designs such as the CQR (articulated plough) and Bruce (claw), which while HHP capable would not meet the SHHP standard, from newer more efficient anchors.

Anchors can also be tested against others with the desired standard; should they hold at least the same load, this meets the requirement. Its designer confident that superior performance would be displayed, the Rocna anchor was tested by RINA against a New Zealand built copy which already had SHHP classification from Lloyd’s Register. In clay, the Rocna 25 recorded pulls at an average of 6,250 kgf, while the larger Manson Supreme 27 kg managed an average of 4,665 kgf; in soft mud, the Rocna averaged 635 kgf versus the copy’s 560 kgf. In the same locations stockless anchors four times the weight were recording pulls a quarter of the Rocna’s results. Unfortunately such test results are rarely published so inspecting the basis of classification can be difficult.

Anchors incapable of attaining SHHP classification should probably be avoided by boaters in light of the far superior designs which do carry the standard. However, because the SHHP standard in turn does not represent a particularly high bar, this classification is really of little assistance in selecting a type. Look instead to independent testing and feedback from experienced users.

Certification

For larger anchors, the complete rules of the society as pertain to anchors are applied, and these bring with them a little more meaning. Typically these elements do not apply to smaller anchors.

Production facilities are required to be certified according to certain standards, such as ISO 9001. This commands certain mandates, such as accreditation of welders, and speaks to control of other management issues. It provides no guarantee of quality of end products; rather, it simply certifies that certain formalized business processes are being applied.

Other requirements do speak to basic specifications, such as tolerances, heat treatment of castings, weld quality, etc. However there is no restriction on construction and engineering standards or processes which may be poor compromises of the ideal way of doing things – for example, with anchors, laminating steel plate to build up thickness, rather than the far stronger but more expensive use of solid steel.

The strength and durability of anchors may be tested by dropping from some height onto a steel slab, and proof testing of specific loads applied to the shank and flukes.

This specific certification is usually required on commercial vessels over a certain size (depending on local regulations) and often also specified for large private vessels. This certification testifies to the adherence to the above standards by the particular anchor in question. Even if there is no legal requisite, certification is a way for a designer or customer to ensure a minimum standard of quality. However this is highly costly per anchor, and customers of small anchors (under about 70 kg / 150 lb) would never find it necessary.

Once completed to the society’s satisfaction, it is obligatory that the anchor is branded with a number of details, including the society’s name, file number and code of the local inspection office, date of test and reference to the testing documentation, a serial number of some kind by which to trace the anchor’s history, the mass of the anchor, and the labels “HHP” or “SHHP” as appropriate.

To be clear, the advertising of the logo of a classification society’s brand on an anchor does not mean that particular anchor is actually certified. This often refers only to type approval and HHP or SHHP classification and it is typical with smaller anchors. Do not be fooled by the presence of a number referring to the general type approval certificate – all the details above must be listed.

Summary

Classification generally is of little importance, particularly for small anchors. Type approval is of some benefit, but it is unlikely that any anchor brand would last long if it did not meet this standard in any case. HHP and even SHHP are not very high performance standards, easily exceeded by most anchors on the market today regardless of whether they have classification or not.

Certification applies only to larger anchors, and then usually for legal requirements.

Classification and certification is generally obtained by a manufacturer because they find it necessary for their larger anchors. It has a secondary benefit of providing useful marketing tools which can be applied to their smaller range also. Other than the cost invested in the process (which must be passed onto the customer) it certainly does not hurt, but neither is it any panacea.