Innovative application of Brevini planetary gearboxes

The Woolwich Ferry provides an important link for vehicles, pedestrians and cyclists across the River Thames, linking the North and South Circular Roads. The current infrastructure was installed in the early 1960’s and after more than half a century’s service it was decided in 2012 that the facilities required a major upgrade to ensure that the ferry service could continue to operate well into the 2020’s. In addition to refurbishing and upgrading the existing 4 linkspans, the project required the replacement of 160t of operating equipment – including obsolete and unreliable lifting systems.

Briggs Marine Contractors, who operate the ferry under a long term contract with TfL and are managing the overall life extension project, awarded the linkspan refurbishment contract to AMCO Engineering in 2013 and the works were completed in late 2015. In February 2016 the refurbishment project was shortlisted for the Royal Institute of Chartered Surveyors (RICS) London Region Awards for 2016 in recognition of its important role in London’s infrastructure regeneration.

The Brevini drive packages were a key element of the new lifting systems for the refurbished linkspans. As James Chappell, AMCO’s contract manager explained about the project as a whole, “There were three areas that we needed to assess; the linkspans, the lifting equipment and the associated electrical and control systems. Each had their own challenges and in each case we were looking for the best solution that would provide the greatest life extension.”

With their extensive expertise in drive and gearbox technology and application, Brevini’s consultative and collaborative approach was key to securing this prestigious contract with AMCO. With a vast range of product solutions at their disposal, all based on the best, most efficient drive system design, Brevini’s engineers were able to offer an unparalleled level of support to the AMCO team, leading to an innovative application of planetary gearboxes.

The original lifting system comprised of electrically powered winches and wire ropes which were reaching the end of their useful life. To meet TfL’s objectives of increasing reliability and reducing the long term risk and cost associated with the facility, the drive solution offered by Brevini helped dramatically reduce the complexity of the system, complementing new hoisting equipment. The counterbalance system was re-engineered and it now functions as the lifting system and the linkspans are now raised and lowered by rotating new, stronger, counterbalance shafts. This was made possible by replacing the old counterbalance shafts with new assemblies directly coupled to new drive system gearboxes. The new electric drive motor units are fitted to bespoke carrier assemblies which link the motors, via four stage planetary gearboxes and couplings supplied by Brevini, to the counterbalance shafts.

To meet the ferry service’s demands of 27,500 cycles per year (lifting/lowering of the linkspans), and to comply with – and exceed - the operational torque requirements and a design life of 25 years, Brevini specified their S Series planetary gearboxes, with a crowned tooth gear coupling. In line with their philosophy of providing the best technical solution alongside the best commercial option, Brevini’s breadth of expertise enabled AMCO to benefit from an innovative use of these planetary gearboxes, which incorporate state-of-the-art technology developed for the wind-power sector. Not normally considered for projects such as the Woolwich Ferry refurbishment, these planetary gearboxes introduced major space- and cost-savings to the new lifting system. At approximately 1/5th of the size of the previously installed system, the installation of Brevini S Series gearboxes introduced a degree of flexibility to the project – far less complicated than the original lifting system, and helping to meet client’s requirements.

Completed on time, and in budget, this refurbishment and upgrade project represents a major milestone in TfL’s Life Extension Programme for the Woolwich Ferry Service. Brevini’s specification and supply of planetary gearboxes - innovative within this sector - brought significant benefits to the project.

Gonzalo Salvatierra of Brevini UK commented, “We are pleased to have contributed to this high-profile project, and to have introduced an innovative and elegant engineering solution for our client, AMCO Engineering. The project builds on our expertise across maritime, wind and civil engineering industries, where we are fortunate to have an unrivalled breadth of engineering experience coupled with access to a vast product range. That AMCO have been shortlisted by RICS for this project is testament to the whole project team, and we are delighted to have been able to work with AMCO and TfL towards its success.”