“We are thrilled to be at the cutting edge of modern navigation”


Lyttelton Port Company (LPC) has conducted the largest redevelopment in its history, including a channel deepening project. Over the last 10 years the size of container ships internationally has virtually doubled. To accommodate larger vessels, LPC has commenced a channel deepening project which will see an increase in the depth of the existing shipping channel .

As part of the recently completed Stage 1 of the project, the existing 7km shipping channel has been lengthened by 2.5km, widened by 20m and deepened to increase maximum vessel drafts from 12.4m to 13.3m.

The Business Challenge

  • Container vessels visiting Lyttelton carry approximately 4,500-5,000 twenty-foot equivalent units (TEUs) at a draft of 12.4m. The dredging project needed to enable larger vessels at a draft of 13.3m carrying up to 5,500-6,500 TEUs. 

  • Enabling larger, deeper ships to call at Lyttelton Port helps provide the most cost-effective international shipping solutions.

  • The two-stage dredging project is expected to be New Zealand’s largest, estimated to cost between NZD $80 million and $120 million.

  • How to achieve the intended aim whilst minimising cost, operational risk, and environmental impact?

The Solution

Supported by MetOcean Solutions, OMC was tasked with reviewing the existing channel design and submitted two alternative designs for the channel depths: one based on the port continuing to manage under-keel clearance (UKC) risk based on a traditional “static” UKC rule, the other based on implementing state-of-the-art Dynamic Under Keel Clearance (DUKC®) technology.

The DUKC® optimised channel was designed by first creating a comprehensive digital model of the port including complex hydrodynamic models, spatially transformed wave fields, statistical distributions of tidal residuals, and transit parameters including vessel speeds, headings and rates of turn.

Using the design vessel fleet, simulations were performed for 10 years of operations. The vertical motions of each vessel (including squat, heel and wave response) at all points along the channel are calculated to determine the dynamic UKC profile. An in-house optimisation algorithm is run to determine the depth required at all points in the channel to achieve the design channel accessibility.

The Outcomes

LPC performed a cost-benefit analysis and decided to proceed with the DUKC® optimised channel design in conjunction with implementation of an operational DUKC® system. This decision was based on a significant saving in capital expenditure and an ongoing reduction in operating risk. 

The original PIANC channel design required a dredge volume of 9.7M cubic metres. The DUKC® optimised channel required a dredge volume of 5.5M cubic metres. 

Utilising DUKC® for both the channel optimisation and operations resulted in reduction in dredge volume of 4.2M cubic metres or 43% compared with the original PIANC channel design.

  • Reduced required Stage 1 dredge volumes compared with the PIANC design by 43%. 

  • Compared with next best alternative, DUKC® reduced dredge volumes by 800,000 cubic metres – reducing the capital cost of Stage 1 dredging by 15%.

  • Reduced project duration and environmental impacts.

  • Daily shipping operations supported by detailed science-based calculations, taking into account the latest measured tide and wave conditions, high resolution forecasts, and state-of-the-art vessel motion modelling to manage transit risk.

  • Mitigate the impact of sedimentation patterns in the deepened channel to schedule optimal maintenance dredging to ensure minimal impact on vessel accessibility to the port.

Media Coverage

New Channel Ready For Use

Bigger Ships Able to Call at Lyttelton, Following Channel Enhancements

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The operational DUKC® is supported with modelling and forecasting provide by MetOcean Solutions. MetOcean Solutions, a division of New Zealand’s MetService, has a long history working together with LPC, providing high value scientific consultancy services to support port design, capital & maintenance dredging and port operations.
MetOcean provides high-resolution wave forecast as an input to the DUKC®. The numerical models developed in-house characterise the wave climate both in and outside the harbour, producing customised marine forecast. The DUKC® system also ingests wind observations from MetService’s wind sensors installed at Lyttelton Port.
MetOcean science team have undertaken a long-wave (infragravity waves) assessment, applying wave transformation techniques to downscale the wave climate from the outer Lyttleton Harbour into corresponding swell and long waves along Cashin Quay.  Long waves can energise a moored ship and cause excessive movement and surging against the mooring lines. LPC now has access to an operational long-wave forecast, used as a proxy for the excitation potential that could occur. An accurate long wave forecast improves operational efficiency, safety and reduce direct costs from ruptured lines.

In addition to the DUKC®, OMC has designed, procured and delivered to the Port two Miros SM140 RangeFinder systems. Using in-house data processing algorithms, these radar gauges deliver tide, sea, swell, infra-gravity and far infra-gravity wave data, quality controlled to the highest standards. The data processing is supported by comprehensive data management and user displays.

Peter Davie, Chief Executive,

Lyttelton Port Company


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“The new system will improve the safety of all commercial shipping movements within the Harbour and allow larger and deeper draught container ships to call at Lyttelton.”

Peter Davie, Chief Executive,

Lyttelton Port Company

"DUKC® is an intelligent software tool that Pilots use to determine whether or not it is safe to transit large vessels in or out of the Port."

Lyttelton Port Company