A number of international classification societies offer classification of marine anchors, which in turn is advertised by the approved anchor manufacturers. Phrases such as “HHP”, “SHHP”, and “type approval” are in common usage. However, informative summaries of what these classifications actually mean tend to be in short supply – even from the classification societies themselves.
Manufacturers tend to 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 can be very misleading.
So what does it all actually mean?
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.
Generally there is equivalence between the various societies. Standards as defined by the regulations from different societies tend to be interchangeable. Often, 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 definitions apply to all societies.
Type approval is an abstract endorsement by the society of the anchor’s design, or “type”. A considerable cost is charged by the society, which takes several months to inspect the manufacturer’s production drawings. They then either approve the design, or request modifications according to supplied comments.
This inspection makes no comment with regard to patent infringement nor the actual effectiveness of the anchor if it is a copy of another type, classified or not.
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, so it is this which would be the better indicator.
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:
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 to easily exceed even SHHP.
Further, the testing which inspects whether or not a contender meets the standard is very simplistic and involves a limited number of trials and only unidirectional pulling. The classification thus says nothing about some of the more important behavioral traits of any anchor, such as its roll stability and how it handles veering loads.
Note: many (most) older anchor types, at least those from reputable manufacturers, have HHP classification. This does not mean they are incapable of meeting the SHHP standard, only that the newer standard was not available when they were classified. Many older anchor types are probably quite capable of achieving SHHP. Whether or not the manufacturer can be bothered going through the classification process a second time, particularly before SHHP is widely recognized and demanded, is another question.
Does this mean that an HHP anchor is just fine as a choice and SHHP is not worth looking out for? Probably not, because it is older anchors which have HHP and the more modern anchors tend to be far superior anyway, regardless of classification. It just means that the presence of HHP or SHHP does not mean much with regard to performance. Look instead to independent testing and feedback from experienced users.
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.
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.