Consider design carefully before you end up back at the drawing board

According to recent statistics released by the Office of Rail Regulation, the number of rail journeys taken in the UK has more than doubled in the last twenty years. More than 1.27 billion train journeys took place in the country between March 2012 and 2013 and this number is continually rising.

As the number of passengers has increased, the pressure on train designers, manufacturers and operators to ensure that trains run smoothly has become far greater. Failure in service makes a huge direct impact on revenue and can lead to costly penalties in terms of running hours and repair costs.

To ensure that all elements run smoothly, very high levels of testing and inspections are put in place to stop any issues before they arise and reduce the amount of downtime, but is this the most efficient way to diminish faults and combat any problems that may occur? From our experience at Romax, we have found that the key to minimising issues lies in the integration process – whether that be the components or the manufacturers themselves, integration needs to be a crucial consideration which is addressed right at the beginning of the design process. 

When it comes to assembly, parts are brought in from various manufacturers and assembled to create rolling stocks, and while all of these individual parts can be of a high quality and serve their purpose, problems can sometimes arise when they are put together. Using fast and accurate design software at the initial stage of development that involves the creation of a full system model, allows for parametric studies such as investigation of manufacturing tolerances and system optimisation. This creates information that can be harnessed to eliminate the root cause of failure, which could be something as simple as bearings settings and minor misalignments.

With the number of train journeys taken increasing, it is more important now than ever before to make sure that issues are solved promptly, and eradicating them by identifying any compatibility issues in the initial design process is something that rail operators are increasingly finding value in.

An example of an organisation taking this proactive approach is Irish Rail, a national provider of rail and related services in Ireland. When it started to experience several incidences of premature breakdown in rolling element bearings that resulted in serious impact to the running of the business, it decided to consult Romax Technology to fix the issue. Romax performed a full review of design and service data, physical analysis of the axle box bearings and simulation and modeling using in-house developed driveline analysis software RomaxDESIGNER.

RomaxDESIGNER is a virtual product development and simulation environment for the design, analysis & NVH exploration of the complete driveline – from motor to wheel including gearboxes, bearings, couplings, electrical motor and supporting structures such as bogie frame, axle and wheel. It is designed to significantly reduce the number and length of design cycles by considering all systems effects in just one transmission model. From the initial concept stages, component lives are calculated providing a fast and efficient method for system development. With the information gained from the analysis by Romax, Irish Rail is now in a better position to rule out issues that contribute to its axle box bearings problems. 

Assessing the durability of a system by replicating failures in an efficient design software program remains one of the fastest and cost effective ways to pin down the root causes of failure in gears and bearings before any issues arise. Railway operators are in a high-pressure environment where they need to ensure that consumers are able to use their services every day and one failure can have a domino effect on an entire system. With this in mind, and with the number of train journeys in the UK increasing, it’s time to place more emphasis on the design process now to make minor compatibility issues a thing of the past.