Project Name: Refurbishment of Lemonthyme Penstock

Owner: Hydro Tasmania

Customer: Lothway TBS

Total Area to Refurbish: 16,500 square meters (177604 ft²)

Coating removed:  Coal Tar – first pass with UHP water, second pass for cleanliness, flash rust removal and to effect a profile – RIPT dry abrasive blasting.

Equipment Set-up:  Robotic Internal Pipe Tool (RIPT) with bulk pot and 2″ blast hose, GMA Speedblast garnet

The refurbishment of the Lemonthyme Penstock presented a unique challenge due to the large area that needed to be renovated. In order to effectively remove the existing lining, Hydro Tasmania turned to the use of an autonomous waterjet crawler robot with a vacuum head. This innovative solution allowed for the removal of 500 square meters of lining per shift, significantly speeding up the process.

Once the lining had been removed, it was necessary to prepare the surface for the new lining to be applied. This was achieved through abrasive blasting, which involved the use of high-pressure jets of abrasive particles to clean and roughen the surface. On this project, the team was able to achieve an average of 80 lineal meters in 10 hours, or 800 square meters per shift. Some shifts were even more productive, with the team completing 110 meters in a single night, resulting in 1,000 square meters being prepared per shift.

To ensure the success of the project, BlastOne furnished onsite support personnel every day of the project. This provided the team with the necessary expertise and guidance to complete the refurbishment efficiently and effectively.

Overall, the use of advanced technology and the support of experienced personnel allowed for the successful refurbishment of the Lemonthyme Penstock, resulting in a fully renovated surface area of 16,500 square meters.

Hydro Tasmania approached BlastOne regarding the refurbishment of the Lemonthyme Penstock at Lake Paragana.  Refurbishing the interior of the sprawling penstock would require, in total,  blasting and painting 16,500 m² (177,604 ft²) of steel surface.

Previous Performance Results:  15 m²/hour (161 ft²/hour)

LINER REMOVAL

Instead of traditional blasting, Hydro Tasmania leveraged an autonomous Waterjet Crawler to remove the inner coating.  This saved untold man hours and mountains of abrasive.

• The robotic waterjet was able to accomplish 500 m² (5,382 ft² ) of lining removal per shift, and used a vacuum head to dispense with the discharged coating

FLASH RUST

Leveraging water to remove the coating resulted in an expected “flash rusting” of the interior surface.  This would need to be blasted.

However, leveraging a RIPT (Robotic Internal Pipe Tool) with 3 rotating nozzles, and Premium Blast Australian Garnet, the savings in man-power and abrasive to remove the flash rust (as opposed to the coating itself) was clever and profitable compromise.

• The RIPT averaged 80 lineal meters in 1 night = 800 m² (8,611 ft²) per shift
• Some shifts achieved 110 lineal meters = 1000 m² (10,764 ft²) per 10 hour shift

HOLDING THE BLAST

• Dehumidification (DH) was used to hold the blast
• Primer was applied with extended wands

COATING

• All paint was pumped from outside to the Plural pump that was on the internal of the Penstock
• (no open containers inside penstock)
• ¾” heated airless hose was used to push part A up to 200m (2152 ft)

Customer was blown away with the productivity. A project that was running behind schedule, caught up to schedule.