Trams have operated continuously in Melbourne since 1885 and they remain a crucial part of the sprawling city’s public transport network. Today, the network operates as ‘Yarra Trams’, carrying hundreds of thousands of passengers each day. To help improve reliability and the overall passenger experience, the Yarra Trams’ fleet underwent a major uplift project which began in 2018. This task has been undertaken by Downer Group, a company heavily involved in rail infrastructure, and it began with a substantial investment, explains Jarred Rowland, Operations Manager, Downer.
“This site in Preston used to be a tram storage facility but we have invested heavily to upgrade it. The scope of the project is an ‘uplift’ of about 95% of the Yarra Trams fleet. The older Z Class and B Class trams get a full stripe down to a bare metal frame followed by a full inspection and any repairs. From there, they are prepped, painted, reassembled and commissioned before returning to service. The younger C Class and D Class trams come in for a smaller package of work. All up, we will process around 430 trams over five years.”
With the painting process taking up a sizeable chunk of the allotted time, a tram-sized spray booth was installed, while at the same time, Downer Group went in search of a suitable paint system. This led to a strong partnership with PPG’s Commercial Performance Coatings team who were able to offer a selection of products that slashed production time while delivering a premium quality end result. Following a stringent and exhaustive testing process, Commercial Performance Coatings product technologies are now making a strong contribution to the process, according to Jarred.
“Previously, we would prep the tram, apply primer, shunt the tram out of the booth to sand it, then shunt it back in and topcoat it. Sanding the primer took two days, with four guys working in two shifts! What PPG has assisted us with is PP3450 Paraglaze CT 2K HP Epoxy Primer which we use in Wet-On-Wet mode. This has allowed us to take two shunts and all that sanding out of the process. We have been able to reduce the painting tack time (cycle-time) from around seven days, down to three days on a B Class and two days on a Z Class.”
For a glossy, durable coating, the tram exteriors are topcoated with 625 Polythane (an ultra-tough, premium polyurethane), while the interior gets a coating of Performance Polyurethane Topcoat in a satin finish. This is backed up with ongoing onsite training in application techniques and OH&S requirements. PPG also supports the project in a variety of other ways, Jarred explains.
“The Commercial Performance Coatings team really helped us when it came to procurement of new equipment. For example, the painters are all fitted out with top quality SATA spray guns and SATA Vision 2000 Air-fed Hoods. They also introduced us to MIRKA sanders, as a replacement for the domestic electric sanders we were using. The guys are more than happy with the MIRKA sanders and they have significantly sped up the process. As part of that, we also use MIRKA Abranet NetSanding abrasives – we get a big reduction in dust and the abrasives don’t clog so they last longer.”
On average, the Downer Group team completes nine tram uplifts per month and at any one time there are 14 trams in different stages of the process. Meeting the tight time targets takes military style precision, a comprehensive set of step-by-step processes, good equipment and skilled staff.
“There are around 120 personnel onsite and about 50 would be touching the trams at some time, whether it be electrical, mechanical, welding, painters, etc. We are currently at around 30 working days turnaround time for each tram but we are ultimately aiming to get that down to 25 days. With our team and the support we are getting, I am confident we will get there!”