PERMANENT WAY
Industrial technical advisor Rob Taylor discusses the latest attempts to protect rail switches from harsh weather and environmental conditions.
T
raditional lubricants have been used in the rail industry for generations. In
years gone by, maintenance teams made up their own concoctions of plate oils to suit the track and weather conditions. Early attempts to produce lubricants were of- ten sticky, black and bitumen-based, un- like some of the current lubricants which can be heavily loaded with solids such as graphite or molybdenum disulfi de, and which in some cases are not bio-degradable or environmentally friendly.
Fluid oils and greases tend to be used in the colder seasons to overcome the low tem- perature and fl uidity of the lubricant. Air temperature and weather both play their part in how a lubricant performs out there in track. The unpredictable British weather can be a hurdle for even the best lubricants in the market place to overcome!
Harsh environments
Rail switch components are exposed to wa- ter, contamination from dust and dirt, ul- tra-violet radiation, ice, snow and temper- ature changes. Interacting forces between rails and wheels cause lateral creep forces and operating pressures that often exceed the lubricating capabilities of conventional lubricants. As a result, most points experi- ence serious impact from wear and need frequent re-lubrication intervals.
By their nature, conventional oils and greases can be washed off the slide chairs during rain and heavy showers. At the same time, they attract sand, brake dust and other debris typical in railway environ- ments. The slide chairs then act like ‘dirt magnets’. This debris, in turn, causes fric- tion and wear and shortens lubricant life.
It is therefore good practice to clean switch 74 | rail technology magazine Aug/Sep 11
Above: Before and after
components regularly and especially be- fore each lubrication visit; unfortunately this leads to increasing time spent on track.
Most importantly, it is found that a large per- centage of rail fractures occur near switches. It is often theorised that these fractures re- late to the lateral creep impact forces that occur when the car enters the switch.
These forces are caused, in part, by the in- evitable differences in friction between the switch rail and the relatively stiff switch heel due to insuffi cient lubrication of that critical part of the switch.
Root cause
In spite of frequent re-lubrication, switches are often the root cause for track problems. In addition, maintenance fi nds it necessary to replace switch motors, switch rails and other moving components regularly. In fact, switches make up a major percentage of railway maintenance costs.
Today’s railways operate at a higher speed of travel to the ever-growing commuter sector. Never has it been more important for the rail industry to look at new ideas to drive down their operational costs.
This poses challenges to the busiest of rail- way networks in the world. Environmen- tal considerations, access to track, shorter possession times and lean maintenance teams are pushing the railways to look at new technology and innovation.
Dutch company Interfl on has been devel- oping its unique lubrication technology with Tefl on. The companies’ willingness to develop this innovative technology, along with the support of rail companies and component OEMs worldwide, has led to
a number of infrastructure fi eld tests on global railways with remarkable perfor- mance improvements and short to long term fi nancial gains.
Such tests have proven to use up to 90% less product over traditional track lubri- cants. Interfl on believe that they have the solution to push the lubrication and main- tenance boundaries to another level.
So what are the benefi ts to using this prov- en technology on rail switches? Four to six weekly re-applications to switch slide plates using only 4ml (a teaspoon) of lubri- cant; it can be applied in all weather condi- tions, including torrential rain and sub-ze- ro temperatures; it’s biodegradable, whilst giving good corrosion protection; it creeps under the switch heel and reduces lateral load forces; it reduces friction and energy when throwing a switch by as much as 50%; no need to throw the switch when re- lubricating; upright application through a metered back pack for worker safety; one product for all seasons and varied rail ap- plications; resistant to ice adhesion in win- ter; it’s a dry coating technology to reduce contamination; and it is faster in applica- tion, meaning less time is spent on track.
The product is a real multi-functional lu- bricant; and it has many uses through- out rail
infrastructure. More recently,
the product is being tested as a fi shplate lubricant. Initial trial results are promis- ing, in both speed and ease of application but also durability.
Rob Taylor
TELL US WHAT YOU THINK
opinion@railtechnologymagazine.com
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92