Tag Archives: Add new tag

Moorings Northland Standards

Posted on by

Our Standards
There are a range of standards and components use throughout NZ in the mooring service industry. Moorings Northland balances quality and value and that means you are paying a reasonable price for the best possible workmanship, engineering design and highest industry standard components. This ensures your asset will last longer, be more economical to maintain in the longer term and above all, you can sleep soundly on a stormy night knowing your mooring is one of the best serviced moorings in New Zealand.

Our Mooring barge ‘Lifter’
Our purpose built 12m barge is designed to service existing and lay new moorings to the highest degree of accuracy and efficiency currently available. The barge is operated by Shane and Norm who have combined shipping, engineering and marine industry experience.

The components we use:
• Mooring Blocks – Moorings Northland have designed and use new two and four ton mooring blocks with twin eyes. These blocks are designed to last significantly longer than single eye blocks.
• Bottom Chain – we only use 38mm stud link chain (approximately 15 – 20 years life). Each link weighs approx 5kg.
• Top chain – tested and ‘certified’ top chain 20 or 16mm (lesser grades or cheap uncertified chain is not recommended as it can be unsafe to service, prone to excessive and uneven wear or even failure due to poor metal composition).
• Swivels –the best industry swivels available – (there are inferior grade swivels with inherent design faults which are known to fail in marine applications.
• Shackles – are made of compatible self coloring mild steel. They are on average 6mm in diameter larger than our rated chain. Thus have greater wear capacity than the chain.
• Head rope or strop – three lay marine approved polyester or nylon rope appropriately sized to suit either a two or four ton mooring.
• Thimbles – galvanized thick walled. All sized to offer maximum protection to your strop/head rope.
• Anti chafe – thick walled long life UV stabilized amalgamated rubber plastic specifically sized to fit your strop/head rope.
• Floats – foam filled buoys with inherent buoyancy if damaged. We also offer a range of other float systems of reputable and proven quality.
Our Workmanship
• Welding – all shackles are fully welded around the circumference of each shackle pin. Our electrodes are ‘test certified’ and designed to minimize differential corrosion. The actual weld type is a deep penetration convex fillet DC weld.
• Splicing – our splicing is of the highest quality. The length and number of ‘tucks’ comply with international maritime standards. Loose ends are heat treated and secured with cable ties.
• Cutting – to prevent steel filings damaging you boat during servicing operations, all metal components are cut with oxyacetylene cutting equipment. (We don’t use angle grinders).
• Tying alongside your boat – The barge “Lifter” is very maneuverable and fitted with large yellow full length fenders. As a result we can service you mooring with your boat still attached. We also remove our boots before stepping onto you boat.
• Assessment – vernier calipers are used to objectively assess the thickness of your chain and mooring block eye. Similarly we give you a percentage wear report on your swivel pin, collar, eye and bow.
Our services
Servicing, Upgrading, New installations, Engineering and design advice. Mooring condition report, Dive recovery service, Buying, Selling and Renting, Support on resource consents including appeal processes. We also have the most accurate and up to date mooring information data base for Northland.

Did you know?
Over a three year period including Council fees and servicing a mooring costs $1.00 per day to maintain!

Did you know non standard moorings are more expensive to maintain?

Posted on by

Non standard mooring systems are significantly more expensive to maintain than a standard mooring system. They are also less effective as a mooring system.

Most non standard moorings are made up of several components consisting of large lengths of chain and shackles and numerous metal objects.

All these materials contribute to ongoing and expensive maintenance of your mooring.

For example, electrolysis is created by a reaction between different metals such as mild steel, cast iron and other ferrous/non ferrous metals. The electrolysis then reacts on the least noble metals (usually the chain and shackles) causing accelerated metal wastage. As a result chain and shackles have to be replaced more regularly when their wear exceeds the minimum standards.

Untangling, removing and replacing parts on a non standard mooring takes considerable time and money. Further, this type of mooring due to its makeup usually requires more chain and shackles than a standard mooring. The photo to the right is an example of how uneven wastage can occur to chain.

Less Effective
Not only is a non standard mooring more expensive to maintain, it is also less effective than a single mooring block system. Multiple blocks are prone to entanglement with chain or head rope, they have less lateral and vertical drag resistance compared to a standard 2 or 4 tonne block and generally are light in weight as cast wheels weigh approximately 250 kg each.

Electrolysis issues in Russell, Bay of Islands

Posted on by

While servicing moorings in the Russell area we have identified a ‘high electrolysis activity zone’ in the northern end of the Russell mooring area.

Environmentally occurring electrolysis zones are known to occur in random locations along the Northland coast. There are also areas where human induced electrolysis occurs in varying degrees.

The jury is out as to whether the increased level of electrolysis is environmental or human induced – it may be a combination of both. The current levels of electrolysis are causing accelerated wastage to mooring components – particularly top chain and shackles.

In recent months four moorings have failed due to accelerated steel wastage caused through electrolysis and corrosion. In the last year there have been over eight mooring failures due to electrolysis.

To identify whether there has been an ongoing issue with electrolysis in this area we discussed the issue with the Maritime Section of the Northland Regional Council including one of their staff who previously worked with the Harbour Board. He recalls high base levels of electrolysis in the bay which suggests that it’s presence isn’t recent, but its affects appears to have increased .

What you can do?

Given the increased levels of electrolysis and recent history of mooring failures, it would appear that the three yearly service regime is too long for this particular location. After discussions with the NRC we recommend that all mooring owners consider adopting a two yearly service regime for their mooring as a precautionary approach to protecting your boat.

What Moorings Northland is doing?

Given the implications of these issues, Moorings Northland has changed it’s work practices to protect your asset and our reputation by:-

· Using 20mm certified chain, instead of the minimum 16mm certified chain. Using the larger chain provides greater mass and thus safer margins against wastage.

· Using 26mm shackles instead of the minimum 22 mm shackles. One of our findings revealed that the smaller shackles failed. Particularly shackles that were only ‘tack welded’.

· Fully welding the pin on all shackles with an ‘electrically natural’ electrode. Moorings Northland never ‘tack welds’ as this form of securing shackles is known to fail.

If you have any queries or would like to alter your service regime to two yearly please contact us on 09 4026939 or email mooringsnorthland@xtra.co.nz and we will alter our records accordingly.