Norbar Case Study

Bombardier Flexity E-Class Tram Intermediate Coupler Installation

A Customised solution for torquing of bolts with obstructed access.

About Bombardier Transportation

Bombardier designs, engineers, manufactures and maintains rolling stock including trains and trams, with 22 locations across the Australia, headquartered at the manufacturing hub in Victoria.

Bombardier Flexity E-Class Tram

The E-class trams are three-section, four-bogie articulated trams designed for excellent performance in Melbourne’s climate and to operate on its existing rail infrastructure. E-Class trams are built at Bombardier’s Dandenong factory, with the propulsion systems and bogies coming from Bombardier factories in Germany.

Maintenance and Upgrades

As part of routine maintenance and equipment upgrades, the client was required install a new design of the intermediate coupler tail-stock.

The installation was originally performed with a rattle gun to pre-tighten the joint (M36 nyloc nut), followed by a bulky hydraulic cassette wrench for final torquing to 1800 Nm.

With the changes to the tail-stock design, there was now only 69 mm of clearance available above the bolts which precluded the use of a rattle gun as was the previous method.


Image: The Norbar PneuTorque PTS-72 2000 Nm Multiplier and the custom design OSD in use.

Norbar case study graphic

Engineering the solution

The Norbar mechanical engineering team worked with the client to develop a custom Offset Drive (OSD). This allowed the obstructed bolts to be accessed by positioning the torque tool adjacent to the bolt, rather than directly contacting on it for torquing.

The OSD was engineered to be simultaneously lightweight and powerful, featuring an aluminium housing so that it is around two thirds lighter than a steel equivalent.

The OSD housing contains tightly toleranced steel gears that provide the 1800 Nm of torque needed, while causing minimal wear to the gears for a long and reliable product life.

Custom Offset Drive for Bombardier
Image: The custom designed Offset Drive.

The Outcome

The custom-designed OSD when combined with the Norbar PneuTorque PTS-72 2000 Nm Multiplier provides easy, safe access to the tail-stock bolts.

The multiplier provides direct drive for smooth continuous rotation allowing for comfortable, uninterrupted operation.
The entire operation can now be completed with a single tool and OSD, saving significant time over the previous method which required swapping to a second tool to apply the final torque.

With this solution, the installation could be successfully completed with additional benefits and savings:

  • Accuracy and reliability — Application of torque to the M36 nyloc nut is controlled and accurate, eaily providing the 1800 Nm of torque required.
  • Safe — The OSD allows the operator a safe contact point on the joint during the installation process.
  • Labour halved — The operation can be completed by a single technician, where previously two were needed; labour was effectively cut in half.
  • Custom solution — Custom designed OSD is tailored to exactly fit the new configuration of the tail-stock bolts, streamlining the bolting operation.

Labour Halved

OH&S Risk Reduction

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