THROUGHOUT the world, railway owners, operators and maintainers constantly seek new ways to improve efficiency and reduce the cost of maintaining their systems in what seems to be an ever-reducing time window for possessions.
Typically in Asia and Australia these windows range from three to five hours, and simply transiting to and from the worksite can occupy most of the available time for maintenance. Experience has shown that embracing latest technology and innovation to make the best use of every available minute brings numerous benefits to the owner, operator and/or maintainer.
Much research has been dedicated to finding new ways to improve task efficiency during brief possessions, but unfortunately in some parts of the world the railway industry has been very slow to embrace change and in some cases for good reason. For example, it is still common for track surfacing machines (tampers) to have a team of surveyors and labourers measuring from reference data plates (using a plumb bob and straight edge) to determine how much track requires lifting and lining. Technology has been available for some years now whereby a survey trolley is used in conjunction with one or more robotic total stations to accurately and quickly survey the existing track location, compare the data to an alignment design string and provide the tamping crews with lift and line data.
This invariably reduces errors, increases outputs and reduces overall maintenance costs, not to mention reducing the risk of exposing a larger number of workers to a hazardous environment. In countries where labour is still relatively cheap, the benefits of introducing such technology may not be as evident in the short term as in countries with a higher labour cost component.
Another improvement that has been slowly adopted by the railway industry is the use of switch and crossing and track handling equipment, such as Geismar PEM/LEMs. These units enable large turnouts to be pre-assembled off site and carried to the worksite safely and quickly, thereby reducing the installation time for complex pointwork. One of the main constraints to introducing such technology has been the high capital cost and the limited number of opportunities for cost recovery. Over the past 5-10 years larger government investments in railway infrastructures and their maintenance have enabled such equipment to be introduced.
On metro systems such as MTR in Hong Kong and SMRT Singapore, night time windows are often as short as 3-5 hours, enabling anywhere between 1.5-3.5 hrs of productive work time, depending on what activity is being undertaken and the distance between the worksite and access points. Transporting crews, equipment, and materials to the worksite is a major consideration when planning the maintenance activities. The use of work trains and other hi-rail equipment to carry workers and materials into and out of the worksite is paramount but potentially time consuming, as access points can be up to 5km or more from the actual worksite. Installing temporary stabling sidings is one way of reducing transit times, but often space and safe working restrictions limit this option.
Deteriorating railway infrastructures will require more attention as passenger numbers increase and systems age. Experience has shown that when the following are taken into consideration in conjunction with the latest technologies and innovation significant benefits can be gained:
• equipment choice
• training and resources
• temporary and permanent materials, and
• independent assessment of activities.
The choice of equipment is a simple but effective solution to increasing efficiencies. For example, on overhead line maintenance where bolts need to be regularly checked and tightened, the use of smaller air-operated tools significantly increases productivity. Furthermore, sufficient items of equipment must be available - and properly maintained - to enable the work to be completed effectively. Poorly maintained equipment can have disastrous outcomes. Keeping equipment on close standby during any possession is essential.
For a maintenance team to perform to their highest potential they require ongoing training and multi-skilling. Over time typically repetitive activities become second nature and productivity will increase. Careful consideration of the skill set and in particular the number of resources on site is important. You often see a cast of thousands on possessions which frequently leads to confusion, inefficiencies, and an increased risk of accidents.
Quite often within organisations there is limited opportunity to change the permanent materials for various internal reasons but the choice of temporary materials is definitely an area to consider. Design temporary materials with ease and speed of installation in mind (obviously, functionality and safety remain key considerations). For example, a simple quick install or release mechanism can shave crucial minutes off your possession.
Close assessment of each task by an independent person - not necessarily somebody with railway experience - can yield some interesting outcomes. These people tend not to be influenced by how things have been done in the past and brainstorming their ideas with the team can result in innovative solutions. Encourage your team to think creatively. Try different ideas and fine-tune them as you go; often you will come up with more efficient ways of working.
I once worked with a mechanical engineer with minimal railway experience who achieved a 12% improvement in the output of a tracklaying machine, by introducing relatively simple and quick changes to the methods and the machine. This increased the output of the machine from 5.8 to 6.5 sleepers per minute during a five-hour possession.
The unit cost of replacing sleepers during a possession increases exponentially as the possession time reduces below a cut-off point (activity dependent). The unit cost decreases (for a fixed possession time) as the productivity increases.
Possession window times are not going to increase, and if anything they will decrease as traffic levels rise and commercial pressures increase to keep lines open for longer periods. To ensure that rail systems continue to operate safely, efficiently and cost effectively, applying technology and innovation should be a major consideration for owners, operators and maintainers.
