Fix before it fails

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Pioneering new software technology developed by Voith Turbo, now being used on over 600 buses in the UK, has cut gearbox costs by as much as 68% in at least one UK depot.

The dramatic savings confirm the view of the leading European bus transmissions specialist that the UK bus market is moving away from the traditional ‘fix on fail’ policy to a ‘fix before failure’ culture.

John Domigan, Sales and Marketing Manager, Voith Turbo

The technology – the first of its kind in the UK bus industry – has enabled Voith Turbo to offer a health check scheme to bus operators so they can avoid transmission failures by introducing timely gearbox maintenance programmes.

A year ago only two depots were using the scheme. Today more than 600 buses at 16 depots are making big savings on transmission maintenance costs – and many more are queuing up to take advantage of the health check initiative.

Preventative cures

“We have found that if we can anticipate the failure of a gearbox and repair it in the field we can save significant sums by avoiding the need for a replacement transmission,” says John Domigan, Voith Turbo’s Sales and Marketing Manager.

“One depot reported that across its fleet of 50 buses it had saved 68% on gearbox maintenance costs in nine months – and that figure didn’t include associated costs such as downtime and the cost of towing broken-down vehicles to the depot.”

He says that the drive to a ‘fix before fail’ culture was being led by depots. “Every year their budgets are under increasing pressure and they can see that by cutting maintenance costs, downtime and lost mileage they can save money,” says John.

“Typically the process of offering a health check scheme starts when a gearbox fails. Our services engineers explain that if health checks had been carried out on their fleet we could have saved them the cost of a new transmission.”

If the operator agrees, a Voith service engineer first reviews vehicles out of warranty, but also carries out health checks on transmissions nearing the end of their warranty period.

Voith’s field supervisor, Sean Donnellan, downloads information onto his laptop from the gearbox’s ECU files

Stream of data

The service engineer, using his laptop equipped with a new software package called Adascanner, then downloads a stream of information from the bus fleet’s transmissions’ ECU files and analyses all the data. The process normally takes place overnight to avoid service disruption.

A report is compiled detailing the condition of every transmission in the fleet. An action plan is discussed and scheduled to carry out any preventative maintenance where necessary to prolong the service life of the transmission.

Repairs are normally carried out as part of the depot’s planned maintenance programme to avoid any downtime. The health checks are then continued every three or four months.

“This process allows us to build up a very accurate picture of when we might have an issue so we can act before we get any problems,” said John. “We expect increasing numbers of depots to implement the health check scheme next year.”

Technical information

At the heart of Voith’s pioneering technology is Adascanner. While interrogating the ECU, Adascanner monitors the condition of clutch plates that cannot be inspected visually without stripping down the transmission.

Clutch plates can cause widespread damage to other gearbox components when they fail. Therefore, predicting when they are coming to the end of their life is a major breakthrough for Voith Turbo.

“The real bonus with Adascanner is that it can predict when a clutch plate is likely to fail with a high degree of accuracy – probably within a few weeks,” says John.

The Adascanner software measures clutch closure pressures, which are recorded in the gearbox ECU. By measuring slip times the ECU adapts the pressure required for clutch closure ensuring smooth and efficient gear shifts. As the pressure increases it is recorded in the ECU data.

Adascanner takes the data and displays it on a computer screen so engineers can visually see the shift pressures at closure. As clutch plates deteriorate they require more pressure to prevent slipping – indicating they are likely to fail in the near future.

Other information downloaded from the ECU also includes key runtime data such as: –

  • Time splices in the gear ranges
  • Stop-start cycles
  • Average speed (with/without stops)
  • Ratio of driving time to stand still periods
  • Proportion of accelerator pedal and brake activity
  • Proportion of retarder braking operations
  • Operating hours and runtime data analysis
  • Oil and cooling system temperatures
  • Regionally-based Voith service engineers (l-r): Andy Colwell, Nick Gardner and Rob White

Planning ahead

John adds: “Three years ago we collected data from 800 buses in the UK. Engineers were able to establish the optimum clutch closure pressure on each gear on every model of transmission operating in the UK.

“The results convinced us that our new technology could save operators thousands of pounds a year. We were equally convinced that it was in the industry’s best interests to move away from the ‘fix on fail’ culture to a policy of ‘fix before failure.’

“We now believe that the real-life figures from 600 buses in service in the UK confirm our view.”

Voith Turbo is now gearing up to meet the predicted change. The company has just appointed another three people to join its team of regionally-based service engineers who will be able to respond quickly to bus operators’ changing requirements.

Service engineers

Nick Gardner, with over 20 years’ experience in the bus industry including the position of field service engineer for Alexander Dennis, is now covering the south west and south Wales area.

Andy Colwell, having served a five-year apprenticeship with Iveco/Ford, later worked as a field service engineer, is now based at Warrington to support the north-west region. 

Rob White, an experienced engineer in remove and refit operations, is covering the East of England and the Midlands.

Unlike its competitors, Voith Turbo points out that employs its own specialist engineers in the field to help customers, rather than employ agents.

Voith Turbo and its DIWA transmissions

Voith Turbo, a leading European manufacturer of automatic gearboxes for buses, has its UK headquarters in Croydon and employs 150 people across the country.

Soon after entering the UK bus market in 2009 Voith Turbo became a leading supplier to Wrightbus before winning further contracts with the other two UK-based manufacturers, ADL and Optare.

Voith’s gearboxes are today running in vehicles owned by the ‘big five’ operators. In total in the UK, DIWA transmissions are operating in more than 7,000 buses, and over 200,000 worldwide.  

Voith Turbo, set up in the UK over 50 years ago, supplies both the double-decker and single-decker markets.

“Our transmissions are made specifically for the stop-start cycle of buses,” says John Domigan, Sales and Marketing Manager. “Our products are sold on reliability and longevity and we believe there is now a growing awareness in the UK market that price is not the only important criteria.

The latest model is the DIWA.6 transmission: There are 7,000 DIWA transmissions currently operating in UK buses

“We are extremely optimistic that whole life costs are forming a more crucial part of the purchasing decision, and that the longevity of our products – which are at least seven or eight years, and longer in some cases – gives us a competitive advantage.”

He added that customer service is crucial to Voith Turbo’s success. Unlike its competitors, Voith Turbo employs its own specialist engineers in the field to help customers rather than employ agents.                                        

In addition the company makes drive systems for rail vehicles, such as transmissions and rail couplers. The UK rail industry is serviced from Voith Turbo’s plant in Greenford, Middlesex.

Voith Turbo operates globally employing more than 6,200 people in around 60 countries achieving annual sales of €1,470 million.