RUD recently solved a pump removal problem for the largest wastewater pump station for Logan City Council, the Alfred Street SPS69 wastewater pump station.

The Alfred St pump station is located in the Logan Council area in south-east QLD, servicing 200,000 people in the local government area.

RUD’s engineering team worked closely with the Logan Water and Infrastructure Alliance (LoganWIA), a body established to support Logan City Council’s delivery of water and wastewater infrastructure.

Focused on two key outcomes, RUD developed a lifting solution that simplified the pump removal process by devising a specialist lifting device and secondly, ensured that maintenance staff no longer needed to venture inside the wet wells, increasing safety standards.

The Challenge

Previously, the SPS69 pumps at Alfred Street were removed for maintenance using two existing bridge cranes (an existing 10t bridge crane and a smaller 2t bridge crane). This configuration was a major issue for Logan City Council’s operations and maintenance staff, as it required personnel to be lowered into the wet well via a ‘man-cage’ using the 2t crane.

LoganWIA understood this method of removal wasn't a practical or safe long-term maintenance and removal procedure and sought a solution from a lifting and material handling specialists. LoganWIA selected RUD on this project to design and supply a lifting solution that could overcome the existing constraints and hazards.

Upon studying the existing procedures RUD established that:

• The SPS69 pumps weigh 5 tonnes each.
• Each pump sits inside 22-metre-deep wet wells.
• Employees attached 10-tonne crane hooks to the pumps.

When developing the solution for LoganWIA, it was important for RUD engineers to approach a lifting solution with the client in mind. For LoganWIA's unique access issues, RUD focused on two aims: 

• Making the job safer. 
• Overcoming the site constraints for efficient removal and servicing.

RUD‘s team of accredited, in-house engineers specialises in finding solutions that reduce costs, improve safety and boost productivity. With these outcomes in mind, RUD identified the following key challenges:

• Restricted headroom required a compact design solution. 
• This eliminated proprietary systems due to unsuitable lifting bail arrangements.

RUD determined that the station needed new pump lifting points and devices for operating under wastewater and agreed on a comprehensive plan of action with LoganWIA before commencement of the project. 

The Solution

RUD liaised closely with LoganWIA to devise:

• A 6 tonne WLL lift point for the existing pump.
• A 6 tonne WLL lifting device that would operate when submerged.
• The lifting device was designed with a self-latching hook and a remote hook release mechanism.
• The lifting device also features an axial adjustment mechanism to enable perfectly guided lifting and lowering of the pump. The counter weighted design of the lifting device provides a level lift when the lifting device is empty.

A collaborative approach to safety

With a focus on safety and efficiency, a staged approach to solution testing and commissioning was required prior to the lifting devices being passed for use. This involved comprehensive in-house trial procedures including:

• Testing the device and lifting points to twice the WLL under the AS 4991 2004 requirements.
• Testing the equipment on site to ensure it functioned properly.
• Involving key LoganWIA stakeholders, project partners and others relevant personnel.

The Outcomes

The designs for LoganWIA:

• Improve operator safety significantly by eliminating confined space entry requirements.
• Ensure the device retrieves pumps submerged under wastewater, if necessary.
• Prove there's a lifting solution that can be replicated and implemented at other pump stations and deep well situations.
• Offer a compact lifting system usable in low-headroom scenarios.

As part of the final delivery, a comprehensive training manual on the use of the Pump Lifter was developed and delivered to all key stakeholders.

RUD liaised closely with all key personnel in this project to ensure a clear alignment of goals, working to understand the safety and maintenance challenges that were being experienced, then working with the client to overcome these.