journey planner
Underfloor Refresh Now Underway

Following the success of the tram refresh program and as the Supertram fleet approaches its mid-life 15 years of age, the fleet’s running gear requires overhaul. The decision to carry out this work has been brought about by the following factors.

  • Long-term maintenance plan.
  • Routine monitoring and condition assessment.
  • K.P.I trends, continued reliability.

The project will return all the underfloor running gear to an as new condition with Supertram maintenance Staff and specialist contracting companies for the major components undertaking the work.

Work began in May 2009, will take 3 years and 6 months to complete.

A combination of factors has enabled each tram to be approaching 1.5 million kilometres at overhaul. This distance has been achieved by using a comprehensive and flexible maintenance plan, which targets reliability issues.


The underfloor project is an out of sight refresh project. This deals with equipment most people never see. Basically the trams running gear will be overhauled from the chassis down to the rails as follows.

Tram chassis.

  • This will be steam cleaned, shot blasted, anti-corrosion treated, primed and painted as per the as build specification.
  • Bogie slewing ball bearing rings replaced.
  • Bogie bolsters removed, cleaned, inspected, painted and overhauled.



  • Fully stripped down to all component parts.
  • Primary suspension units replaced.
  • Secondary suspension overhauled.
  • Gearboxes overhauled.
  • Drive coupling overhauled.
  • Traction motors overhauled.
  • All cables and cleats replaced
  • Pneumatic systems overhauled.
  • Wheel sets overhauled.
  • Bogie frames stripped shot blasted, crack tested, alignment checked, primed and painted.
  • Brake system mechanisms removed and overhauled all moving parts replaced.

When completed the underfloor equipment will be as new condition, maintaining the trams reliability for many years to come.


As with the fleet refresh, the project is being undertaken in house, at the Supertram Nunnery Depot with the help of specialist contactors.

Major components such as gearboxes, motors, wheel sets and bogie frames will be overhauled off site and re assembled at the nunnery Depot. This enables SSML to have full day-to-day control of the project and its progress. This is essential when maintaining an availability of 23 vehicles each day, out of a fleet of 25 vehicles.


The availability will remain at 23 during the program. This is effectively 23 trams from 24 each day, due to 1 tram being on overhaul. This is a very strict availability, the very same availability was maintained during the fleet refresh program. The experience and knowledge gained during the refresh program, has proven this availability can be delivered.