Case Studies


Our recent projects

Rotowaro Opencast Mine  

Client
Lead Contractor - Leighton Contractors

Contract

Rotowaro Opencast Mine

Duration/Size

To remove 2.8bcm of Overburden per year

Location

Huntly, Waikato

Technical Aspects

Open-cut mining operation
Overburden removal

Challenges

Unseasonally difficult weather conditions resulted in some downtime.

 

Ohai Opencast Coal Mine Pits 

Client
Solid Energy NZ

Contract
Ohai Opencast Coal Mine Pits 16 & 17

Duration/Size
14,000,000 bcm (bank cubic metres) over five years

Date
March 2005 to March 2010

Location
Ohai, Southland

Subcontractors
Orica – Drill and blasting
Transport Services Ltd – Coal haulage

Value
Approx $65 million

Technical Aspects
Open-cut mining operation
Overburden production 2,800,000 bcm per year
Coal production 300,000 tonnes per year

Challenges
Ohai presents a unique and complex geology. It has been mined using underground methods. This results in its own challenges:
Dealing with old workings, unstable ground, and collapsed roofs.
The Southland weather conditions are unique, and result in downtime due to bad weather.

Meeting the challenges
Stevenson Mining have successfully overcome these challenges by implementing streamlined production and water management systems to allow the team to progress the job as soon as possible after rain.
This ‘can-do’ attitude will enable the team to complete the job to a high standard, on time and within budget, delivering the best possible outcome for the client.

 

 

 

Our past projects

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Glencoal Energy (Subsidiary of Fonterra Co-operative Group)

Contracts

Kopako, Renown and Pirongia Coal Mines

Size

9,500,000 bcm

Duration

Seven years (1998 – 2005)

Location

Maramarua

Subcontractors

Nil

Value

Approx $20 million

Technical Aspects

Large scale open cut mining contracts totaling more than 15,000,000 bcm to uncover multi coal seams. Materials included papa mudstone and fireclays.

 

Glencoal Energy (Subsidiary of Fonterra Co-operative Group)

Contracts

Original Kopako coal mine (formerly named Kopuku)

Size

3,000,000 bcm per annum

Date

Started 1948

Location

Maramarua

Subcontractors

Nil

Value

Approx 17 million tonnes of coal

Duration

20 years

Technical Aspects

Large scale open cut mining contracts totaling more than 17 million tonnes of coal. Materials included papa mudstone and fireclays.

 

Oceana Gold

Contract
Macraes Gold Mine

Size
250,000 bcm to embankment plus 170,000 tonne rock mattress

Date
2003-2004

Location
Macraes Flat, East Otago

Subcontractors
Bruce Wilson Ltd – embankment drainage

Value
Approx $3 million

Duration
18 months

Technical Aspects
Tailing dam embankment construction