Complex turbine lift test

HEAVY DUTY RIGGING FOR LOAD TESTING GANTRY CRANE

Queensland Rigging Hire recently solved a difficult lift test with heavy duty rigging, water load bags and over a quarter of a million litres of water. And all this happened in an operating power station.

IT ALL SOUNDED FAIRLY STRAIGHT

forward when the Gladstone Power Station’s management called Kris Pidgeon, owner and director NQCranes to ask for the stations gantry cranes to be load tested to full capacity in anticipation for the first generator changeover in 40 years. The realities of the project were far from straight forward.

NQ Cranes manage the cranes and existing infrastructure throughout the power station. During a site visit NQCranes’ Central Queensland Area Manager Nicolaas Lee immediately recognised several challenges. The space and headroom available to complete the test were quite restrictive, the timeframe for testing to be completed was less than four weeks and the testing of equipment would be at an elevated risk as the station was live and operating.

Complexities also included the utilisation of a custom designed and manufactured spreader bar which had been in storage since the generators were originally installed in the late 1970s.

Pidgeon called Ben Fitzgerald from Queensland Rigging and Hire to discuss the project.

“Kris called and explained the background to the project and I then spoke to Nicolaas and the service contract specialist and engineer Cameron Poole from NRG, at the power station. The quickest way to proceed was to fly up and visit the site and come up with a plan, which I did,” said Fitzgerald.

During the initial visit, Fitzgerald was able to understand the height limitations for the lift, the space they would be working in and the close proximity of other plant and equipment. All this information would enable him to design a rigging solution to fit the environment and the requirements of the power station.

To further complicate matters, Gladstone Power Station is active and was going to be working the whole time the gantry cranes were being tested and with tight tolerances, there was not much room to move in says Fitzgerald.

“I calculated we were going to need 8 water load bags each with a 35t capacity which meant we would safely have the required capacity to be lifting 255,000 litres of water in the air. Working safety in a live power station, with huge volumes of water up in the air, was probably the greatest challenge,” he said. To make this happen, the planning was thorough and detailed and the results of the tests were dependant on this,” said Fitzgerald.

The testing involved two gantry cranes which are permanently operating at the station.

“The load test was designed to ensure the cranes are capable of managing the lift safely. For this to happen the testing

had to be managed in a controlled environment. Effectively, when the power station needs to lift the generator, we have already proof rated the cranes and rigging to ensure the lift goes off without a hitch. This means the station can be confident all the equipment and engineering is fine for the lift to be conducted safely.

“Each gantry crane has a working load limit of 130 tonnes and we tested each to 144t, a 10 percent overload in a controlled environment. The cranes work independently but have the capacity to synchronise and work together with a custom-made spreader bar with a single hook underneath, this increases their overall capacity to 244t. The first two tests were 143t for each crane and the third test for 255t involved both the two cranes combined together with the spreader bar,” said Fitzgerald.

“We knew we were going to have to make everything work that was available to us on site. Dozens of hours of planning went into the lift planning and logistics for the project.

By combining forces with the engineers at Unique Group in the UK, product and rigging specialists at both Queensland Rigging Hire and Dynamic Rigging Hire, as well as the electrical and mechanical engineers at NQCranes, we effectively came up with a safe plan for the testing,” he said.

“After visiting the site, I was confident we could do what was required and I came up with a concept for the rigging based on what was available to us. I sent the lift plan through to engineers at Unique Group who manufacture the Seaflex Water Load bags. They came back with engineering drawings and rigging plans which enabled us to fit within the limited head room, and to utilise the rigging equipment in Queensland Rigging Hire’s fleet,” said Fitzgerald.

The management at the power station were happy with the proposed lift plan and once everything had been signed off, Queensland Hire and Rigging procured some of the required equipment, brought in extra Waterload bags, hoses and manifolds from Dynamic Hire and ensured existing gear was ready to use. The load was then sent to Gladstone on a full semi-trailer for the testing.

“We used eight of Unique Group’s 35t Seaflex Water Load bags for the job. As I have said, the total amount of water contained in the bags was over a quarter of a million litres. From the crane hook down, we used 200t endless gromet slings, we also utilised our 240t capacity Modulift spreader bar, the best manufacturers of modular spreader bar in the world in my opinion,” said Fitzgerald.

“We also used Australian made high quality Delphi Measurement load cells which were monitoring the weights at any given moment. These are calibrated load cells so effectively they are wireless scales, calibrated to National Australian Testing Authority (NATA) certification meaning they are extremely accurate.

“It is important to highlight the point that the crane scales were calibrated

“Rigging the load was the largest element of the testing, and it was a bit of a jigsaw puzzle putting it all together to be able to lift the load into the correct position.”

Complexities also included the utilisation of a custom designed and manufactured spreader bar which had been in storage since the generators were originally installed in the late 1970s.

with our Delphi Measurement load cells. This meant they were adjusted and brought into line with proper accuracy against our NATA calibrated load cells meaning the displays on the crane gave the operators an extremely accurate reading on the weights they were lifting throughout the testing process,” he said.

Delphi Measurement load cells are specifically designed for Australian lifting standards and manufactured in Queensland. Delphi Measurement manufactures a variety of bespoke tension measuring sensors to fit all types of equipment and applications. These cells are used in many industries, where measurement of a pulling or tension force is required. The simple, rugged design makes them suitable for the harshest environments. Load cells are manufactured from a variety of materials including 630 (17-4PH) Stainless Steel, Aircraft Grade Aluminium or Alloy Steel and are available in cabled or wireless versions. The cabled versions are used in permanent mount installations and the wireless versions are typically used in portable applications. The combination of wireless technology and high strength materials make the TW 103 series a lightweight, highly versatile and portable load measuring solution.

For the testing, Fitzgerald and the team ran 12 hour rotational shifts, starting at 6pm and kept going until 6am. 36 hours later the testing was complete.

“As a result of the time spent planning the testing, there were no incidents, and we executed the plan without any hiccups. It takes a coordinated team effort to make a complex project like this work.

“Rigging the load was the largest element of the testing, and it was a bit of a jigsaw puzzle putting it all together to be able to lift the load into the correct position. It took almost eight hours for us to rig the cranes for the 255t test, so you can see it was a very involved process,” said Fitzgerald.

“We gained a lot more experience during this project and will use this in the future to offer our services for similar projects. The client was over the moon and the Central Queensland Manager for NQCranes, Nicolaas Lee said it best via a social media post from NQCranes,” he said.

“Best part of this work was there were no incidents, and everything went extremely well. Thank you to all the technicians involved on the day and night and special thanks to Ben at Queensland Rigging Hire. We all walked away tired but leaving a happy client. Projects like this make me super proud to wear the NQCranes shirt. Well done all.”