Completion Date: June 2017

Seqwater is the Queensland Bulk Water Supply Authority and manages the SEQ Water Grid – an interconnected network of water catchments, storage dams, treatment plants, reservoirs and pipelines. Wivenhoe Dam is the largest dam in the water grid and is one of three Seqwater gated dams. When gated dams reach their Full Supply Level, specially designed gates allow Seqwater to release excess water over the spillway into the creek or river system they are built on at a controlled rate, with the aim of minimising the rise in river levels downstream and mitigating the risk of flood (Source: Seqwater – How Dams Work).

Wivenhoe Dam has a total of five gates to manage water flow and each of these weighs in excess of 100t. In order to open and close the gates, each gate operates using two winch systems. Should any of these assets fail, Seqwater would be prevented from operating the gates and ultimately their capacity to control water impeded. Therefore, Seqwater is committed to ensuring the gates are in good working order at all times.

In 2016, Seqwater engaged Practical Engineering, in partnership with the original winch manufacturer Hägglunds (currently owned by Bosch Rexroth) to assess, refurbish, rebuild and certify a total of 10 winches and the associated mechanical systems including sheaves, bearings, ropes and drives.

The winches for each gate were removed and assessed individually and while each gate was out of commission for testing and inspection purposes, a bulkhead gate was dropped into place. The bulkhead gate is designed specifically to be utilised when gate maintenance or repair works are required.

“Removing the lower sheaves from Gate 1 required careful planning and expert rigging,” says Practical Operations Manager, Jai Rice. “This job gave us yet another opportunity to demonstrate our capacity to manage challenging rigging tasks”.

A range of tests were carried out including hydraulic assessment on the winches themselves, non-destructive testing on the ropes and inspection, rebuild, refurbishment and certification of all associated mechanical components such as the sheaves at our Acacia Ridge workshop. Using Practical’s inspection and testing results, manufacturer Bosch Rexroth refurbished the winches before the Practical team conducted final inspections, certification and managed the commissioning of the winches at Wivenhoe Dam.

In order to meet Seqwater requirements, including the minimisation of downtime, Practical conducted the work over a 13 month period, completing and commissioning final work in August 2017.

Read more about our recent work at Wivenhoe Dam and about our work in the utilities sector. To discuss how we might be able to assist in managing your assets, contact our team on (07) 3875 2133 or email us.