Otago/Southland Branch Meeting – Feb 08

Cable Price Invercargill hosted the Otago/Southland Branch IOQ meeting on 20 Feb 2008.

The meeting, chaired by IOQ Otago/Southland Chairman, Craig McCrorie, was well attended by many local quarry folk,with members of the NZ Executive also present. The local branch elected Lex Robb as the Conference 2009 Chairman and it is clear that their strong team will ensure this 2009 conference will be well run

Presentation by Marc Papke:

The highlight of the evening was a fantastic slide-show presentation on the White Hills Windfarm, Mossburn.
Marc Papke, who originally hailed from Dakota, was Works Infrastructure?s Project Engineer overseeing the construction of the project. Marc is now based in Te Anau.

Key aspects of the project:
Overview:
 Construction of 29 Wind Turbines, each generating 2Megawatts, total 58 Megawatts
 A Meridian Energy / Works Infrastructure project
 Contract period ? March 06 to February 2007.
 500,000m3 of earthworks over five months
 75,000 tonne of concrete and roading aggregate
 Turbine foundations required 12,000m3 concrete, 3,600 tonne cement, 1000t reinforcing steel.
 90 personnel employed at peak of job
 Road Metals main aggregate supplier

Access:
 2km access road required 35,000m3 excavation and fill
 Existing track widened from 3.5m to 10m in predominantly siltstone / mudstone rock
 Dumpsite created at the project were rehabilitated with dozer, topsoiled, seeded and tussock grass planted.
 40,000 tonne GAP65 used in roads.

Turbine Foundations :

Photo of foundations prior to pouring, showing the
huge quantities of steel reinforcing

 20m octagonal shape (to provide better key than circular or square shaped pad) 2.5m depth, approx 800m3
 Trees within 50m radius of each turbine were cleared
 27 bases were ripped with tine and dug out with conventional excavators
 2 required blasting due to harder rock
 Each ?Embed Cylinder? 4.2m diameter, 3m high, 13.2 tonnes, fabricated in Vietnam, and lifted into place with 100 tonne crane and levelled with several adjustable jacks
 Approx 36 tonne of reinforcing steel ? 4 chaps took just 3.5 to 4 days to tie the steel
 Two on-site concrete batching plants supplied by Firth Industries capable of 95m3 /hour and 45m3 /hour produced 395 m3 30MPa concrete for the bases.
 Prior to pouring polystyrene sheeting was placed inside the shutters to minimise excessive heat loss through the shutters
 Temperatures in the core reached 52 degrees C when outside ambient temperatures were approx 20 degrees C
 Pour duration approx 7hours per base.

Towers:
 Lower tower 29m height; Upper tower 39m height
 The Gearbox / turbine / Generator / Transformers each weighed 70 tonne and were manufactured in DenMarc by Nacelle.
 These were lifted into place using Verticonn 400 t (Liebherr 1400/2) crawler crane; weight 370 tonne and 9m width.

Installation of Turbine Blades:

 Fibreglass construction, 39 m length, 6.5 tonne each , three blades per turbine, 50 years life
 Wind-speed sensors at end of each blade detect wind speeds – blades feather continuously to maximise power output
 When winds exceed 80kph, blades feather to zero pitch and do not turn
 Utilisation of turbines world-wide is approx 40%
 Comparison to average utilisation in NZ at 65-70%

Each tower height to top of blade is 101 m.

Transmission Cabling:
 Electrix were contracted to install cables in trenches. Some of these works was undertaken with specialist ?ditch witch? machine which trenches, feeds and lays cable, then backfills Unfortunately, this was not as reliable as the contractor had hoped, and the majority of trenches were dug using conventional digger bucket.
 Power generated from the White Hills Windfarm is fed to Winton substation


At the end of the evening a superb supper was served, and the model Hitachi EX1800 Excavator donated by Cable Price was won by IOQNZ President, George Kelcher. Thanks to our Southland/Otago Branch members for being such fine hosts and to Cable Price for sponsoring a great evening in Invercargill.

George Kelcher, Les Ward and Warwick Leach chat with local identity Mort Crooks (second from left)

Story and photos – Murray Discombe
Windfarm photos by Marc Papke