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Our experience

Karapiro Gate Replacement for Mercury Energy

Transpower

Transmission & Substation Maintenance Services

New Zealand relies on Transpower’s national grid to distribute electricity efficiently throughout the country. In 2020 a storm severely damaged the Direct Current link between the Lake Benmore generation site in the South Island to the Hayward Substation in Wellington. Spread over a vast geographical distance the damage was substantial and the crucial repairs were completed quickly and judiciously.


We played a critical role, collaborating with other suppliers to ensure repairs could be completed on time. We supplied replacement parts for damaged towers, and when required, fabricated completely new towers.   


In a separate project, Transpower engaged us early to develop Parallel Body Extensions for their transmission towers. These extensions can be fitted to existing towers to increase their load capability. We conducted extensive research and testing, and developed a prototype that we managed through the inspection and feedback process. We now manufacture and supply Transpower’s Parallel Body Extensions around the country as they are needed.


Other ongoing work for Transpower includes replacing substation pole caps, as well as maintaining concrete pads and protective coatings. We also fabricate bespoke components for other Transpower service providers such as Downer, Ventia, Omexom and Northpower.

Transpower transmission and substation maintenance by AEC.

“AEC is consistently driven to deliver a high quality, well-finished product within the timeframes provided. Their internal review and QA process with client checks means equipment meets specification parameters allowing for ease of install without delay. AEC have proven themselves, and excel as a go-to for short notice critical works with good outcomes under constrained circumstances.”

Robyn B 
Project Manager - Grid Projects

Mercury Energy

Karāpiro Gate Replacement

Built in the 1940s, the refurbishment of the Karāpiro power station on the Waikato River is part of Mercury’s ongoing Hydro Rehabilitation Project. We were engaged to install three new intake gates to replace the 80-year-old gates that control the flow of water from the reservoir to the penstocks, then on to the turbines and generators. The new 45t replacement gates required precise engineering with a tolerance within 2mm.


We were approached to offer a turnkey solution that included project managing the installation of a new hydraulic system to control the intake gates. 


We have successfully installed the first two gates and are working to embed the third unit’s steelworks from the beginning of 2025.


Our stable skilled site team and Hydro experience is proving invaluable on this ongoing, multi-year project.

Karapiro gate replacement for Mercury Energy by AEC.

”AEC have now fully installed the 1st and 2nd gate with excellent success as we had to adhere to industry-leading tolerances. Presently we are working on the 3rd unit’s embedded steelworks which is critical for the smooth operation of the gate.”

Bede G 
Senior Project Manager, Mercury Energy

Genesis Energy

Tūai Power Station Upgrade

As part of the upgrade of the Tūai Power Station, we were engaged to remove all platforms and ducting within gate one, and to measure, fabricate and fit new platforms and stairs. 


Officially opened in 1929, the Tūai Power Station still retains much of its original construction. The fragility of these aging structures meant our role required careful logistical planning to keep all staff safe while on site and prevent any damage to the existing infrastructure. Adding to the challenge - the remote location of the site. The Tūai Power Station is south of Lake Waikaremoana, over two hours travel from either Napier or Gisbourne. 


Our solution was to undertake multiple trial assemblies before going to site - allowing us to identify and fix potential issues without necessitating a four-hour return trip for additional material or equipment. This solution ensured we would meet the delivery timeline, and the trials allowed us to work collaboratively with the client, who could make modifications to the upgrades before installation.


The outcome was a seamless delivery of quality fabricated assets, safely and within the timeframe.

Tuai power station upgrade for Genesis Energy by AEC.

“AEC were engaged to supply and install access platforms at Tūai, including removal of redundant ducting and damper doors. The project was challenging with multiple contractors working in the same area and a tight timeline. AEC worked well with all the stakeholders, finished their work ahead of schedule and had no safety incidents. Communication during the different project stages of design, fabrication and installation was always timely, clear and professional.” 

Kobus K 
Senior Mechanical Engineer, Genesis Energy

Genesis Energy

Piripāua Penstock Refurbishment

As part of Genesis Energy’s asset maintenance programme, we were engaged to carry out scheduled and reactive works at the Piripāua Hydro site.


We have been working alongside our sister company, CMS, to refurbish the aging penstocks. The project has involved the disassembly and assembly of the main inlet valves, as well as specialist welding on the penstocks with no margin for error. The hydro site is in a remote location on the southern edge of Te Urewera National Park with twisting, narrow access roads that make the transportation of heavy equipment a challenge.


A highly skilled team was required due to the age of penstocks.
Of the two penstocks at Piripāua, the first has now been completely refurbished and we’ve been engaged to proceed with work on the second.

Piripaua penstock refurbishment for Genesis Energy by AEC.

“AEC was engaged to do all the mechanical work required to enable penstock internal lining application by others. The work included main inlet valve removal, penstock protection system removal and replacement, welding repairs, and penstock service water take-off stub replacement. Welding work posed several challenges due to known issues with penstock material, however, clear and timely communication between AEC and Genesis Energy meant issues were resolved, and the work was completed with a high degree of conformance to quality.”

Kobus K 
Senior Mechanical Engineer, Genesis Energy

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