Chicago Transit Authority 5000 Auxiliary Power Unit, A Success Story for TPS

At the start of the supplier selection process for the 5000 series cars, Chicago Transit Authority narrowed down potential APU suppliers from a worldwide source. This validation process was particularly detailed in the selection of manufacturers who could meet or indeed improve on the CTA specification. The supplier qualification process involved reviewing the design, pedigree and response to detailed questioning on the proposed solutions for the project.
After this rigorous selection process, Turbo Power Systems was selected as one of the two preferred APU suppliers. It was a significant achievement for TPS to gain this credibility against worldwide competition from a demanding customer with a demanding application.

Chicago Transit Authority considers that they have one the most severe track conditions in the USA. This is due to the wide weather extremes, track misalignment and the effects of icing particularly on the elevated sections in the downtown area.
On previous rolling stock they had a difficult history on equipment reliability and most of the new design activities were aimed at mitigating pervious failings.
When Bombardier subsequently won the order TPS were their first choice supplier for the APU.
Even though TPS were the favoured supplier, the competition to select the best design, best company perception and performance with the lowest cost solution was intense. TPS eventually won the project on all counts.

There were several aspects of the Chicago Transit specification that made it more onerous.  Chicago Transit Authority had pushed the boundaries on what would otherwise been considered a ‘standard design’.

  • The Chicago Transit Vehicle is quite compact and there is limited space under floor for mounting equipment.
  • The location for the APU was directly behind the Truck, exposed to spray, debris grease and other contaminants.
  • The wide temperature variations particularly in the summer when the vehicle arrives in a station.
  • The track voltage transients added to shoe bounce particularly in the winter.
  • The specific battery charging regime.

Turbo Power Systems with their pedigree and experience worked closely with both Bombardier and Chicago Transit during the design phase to obtain the best solutions for the particulars of the application outlined above.

Various innovations both in circuits and in packaging were introduced into this design to ensure it meets the stringent environmental and operational conditions dictated by the application.

CTA Unit

When the first 5000 Series production prototypes were manufactured, Turbo Power Systems entered into extensive validation programs with thermal test, vibration, noise and other systems integration test to prove the APUs performance.

Turbo Power Systems has now delivered more than 300 APUs that have demonstrated expected performance and high reliability.

TPS is the UK based supplier of choice of APUs to the rolling stock.

Contact Turbo Power Systems for further information

Bombardier Order $3.4 Million New Units

Bombardier Transportation orders new auxiliary power units worth USD $3.4m.

TPS has been a strategic supplier of Bombardier Transportation for over 7 years supporting their contract to supply trains to the Toronto Transit Commission (TTC). TPS have already supplied Bombardier over 700 auxiliary power supply units which are a key part of a distributed power system throughout the train.

Bombardier auxiliary power supply

This project is a proof of TPS’s commitment towards developing cutting edge, efficient and reliable power conversion systems for the Rolling Stock Industry.



To read the full press release, click here.

Turbo power systems Hitachi trains

Japanese giant Hitachi is to move the headquarters of its lucrative rail business to Britain in what is seen as a pre-emptive bid to build the 180mph trains for the Government’s controversial £50billion HS2 line.

Its corporate headquarters will switch from Tokyo to London – with a British executive rather than a Japanese national as global boss – in what minsters hailed today as ‘an incredible vote of confidence’ in the UK. Hitachi Rail was previously at the centre of a furious ‘British jobs for British workers’ row when it clinched a major rail contract for intercity trains ahead of UK-based but Canadian-owned rival Bombardier in Derby.