Steel works cuts switch-plate lubrication costs

A steel works has cut the cost of switch-plate lubrication, cut the number of derailments attributed to lubrication and reduced its environmental impact by cutting lubrication use.

In addition to rolling stock lubrication, one area of major concern to all users of the railways network worldwide is the switch plate.

Switch-plate related derailments, rail fractures and maintenance labour are constantly at the forefront of all rail-track operators.

Rail-track components experience serious impact and wear and as such it is necessary to maintain these components regularly.

In spite of such maintenance, engineering departments find it necessary to replace switch rails and other moving components much more frequently than other rail components.

In fact, switches make up a major percentage of engineering department maintenance costs.

The switches are also a major factor in derailments.

Studies by the Federal Railroad Administration have shown that the majority of derailments take place within 200-300 yards of a switch.

The current practice of maintaining switches involves using mineral oil, grease or graphite to lubricate the sliding plates and rods of the switch.

This provides some reduction in wear of the point and the switch rail for a short period of time depending on rainfall and the environment.

Moreover, lubrication is generally carried out manually three times per week, or more likely once a week or less, and is often left undone for long periods of time, resulting in excessive wear and tear, rail fractures and occasional derailments.

Every year between four and 12 million tonnes of used lubricants are added to our environment and there is growing concern about the potential damage that discarded lubricants may have on ground and aquatic organisms.

Lubricants generally fall into three basic types: mineral, synthetic and vegetable.

Of these, the mineral oil lubricants are considered to be the most harmful as they do not readily biodegrade and are toxic to aquatic organisms.

Biodegradation is the degradation by bacteria.

If certain bacterial strains are able to convert 70 per cent of the lubricant to harmless substances in 21 days, under normal conditions, the product is said to be 'rapidly biodegradable'.

The by-products are CO2, N2, water and mineral salts, which are harmless to the environment.

Rail switch-plate lubrication has been aided by the latest development of rapidly biodegradable lubricants that can increase re-lubrication intervals to two or even three times those previously used.

Kluberrail AL 32-2000 and Kluberbio ALO 32-4000 are synthetic fluid greases free of solvents, which when applied to the surface form a long-lasting lubricating film on the slide plates and with a service temperature range of -40C to 80C it is suitable for most applications.

Following five years of rigorous testing, which included over 3,500 cycles per test for over 80 hours with 30 minutes of rain simulation using 27 litres of water at 60C (to simulate an increased wet environment), with a load of 450N, the surfaces were consistently covered with sufficient lubricating film with corrosion protection.

Throughout the temperature range of -35C to 80C the friction force remained constant between 150N to 250N.

In comparison to a typical non-Kluber switch-plate lubricant currently in use, the results under the same test conditions showed a friction force ranging from 100N (at 25C) to 400N (at -11C).

The test failed due to excessive friction forces at -25C.

In addition to the temperature limitations the material also showed major corrosion issues throughout the tests.

Such a failure could prove catastrophic should the regular maintenance intervals of the plates lapse.

On the basis of this, trials were put into motion by one international major freight user of rail track who previously used a mineral-based lubricant for the site switch plates, which was liable to wash off and contamination.

The results of which, apart from excessive downtime of the site, was the potential for derailment of rail vehicles due to the plates sticking.

In addition to the cost of these issues was the added cost of manpower and lubricant usage and the fact the mineral-based lubricant was not biodegradable, an issue high on the agenda of this company.

Kluber Lubrication was approached following a number of failed trials of alternative lubricants to offer a better biodegradable solution.

Kluberbio AL 32-4000 was offered for trial on some of the worst areas on the site that were predominantly submerged during rainfall, covered in dust and other contaminants during dry periods.

These switch plates previously took three men to lubricate three times weekly.

Trials were initiated on the north side tracks where the plates are subject to loads of 1,200 tonnes of hot steel in a dirty and dusty environment, and on the south side where they carry rolled steel and coils in a similar environment, both also subject to rainfall.

By using a Klubermatic pump the engineers can now lubricate 90 plates with one fill and lubricate once every three weeks.

No derailments have since been attributed to lack of lubrication - previously one derailment at the blast furnace would cost an estimated GBP80,000 per hour.

Due to the lubrication points being continuously lubricated no weekend call-outs to lubricate points have been required.

A reduction of environmental impact has been achieved by reducing lubrication use by over 95 per cent.

Maintenance engineers no longer have to bend over to brush on the grease, they use a spray gun instead.

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