Milling – the new dimension of rail-profiling

It was in 2003 when Linsinger Maschinenbau GmbH from Austria launched its new version of the Rail Milling Train SF 03 FFS for German Railways, DB AG, and Alpha-Rail Team for the German Railway Market. Since then, the rail milling technology of Linsinger started a matchless and incomparable victory lap in the national railway marketplace in Europe, as well as within the international railway and light rail market, especially in Asia.

Used since 1995 throughout Europe from different railway organisations, this highly sophisticated state-of-the-art rail profiling technology has now become the standard technology of more and more railway and light rail systems world-wide.

Linsinger rail milling technology has made a quantum leap in innovative rail treatment. By combining rail milling and grinding in a single operation with a high degree of accuracy and extended conditions of use, a significant reduction in maintenance costs can be achieved.

The integration of milling and grinding in one machine that performs both processes in a single operation, has proved to be particularly cost effective.

Besides the technical benefits of a high level of removal, independent from outside temperatures and the generation of transverse and longitudinal profiles to a high degree of precision in a single pass, the technology integrated in this machine additionally offers considerable potential in respect of engineering operations.

The arrangement of the milling and grinding units renders it unnecessary for track switchgear, check rails and other arrester devices, e.g. shock absorbers, in the track to be dismantled. The lead and follow-up times otherwise necessarily can be dispensed as well as the related cost of employing staff to manually dismantle and refit the equipment mentioned above. Hence, the track possessions available can be devoted entirely to the machining of rails. The result is a significantly higher shift output in the form of finished metres of track.

All Linsinger rail milling vehicles are equipped with high efficient diesel emission filters for sensitive areas.

Field of application

With rail milling technology, processing depths on running surface from 0.1 up to 3mm are covered.

Beside the conventional applications, as reprofiling of the longitudinal and transverse profile, preventive maintenance of rail heads and removal of running surface defects on rail heads (e.g. head checks, squats and impacts) as well as material fatigue removal, further fields of applications are offered.

Narrow gauge correction

The ‘working machine tools’ are very well suited to execute track corrections in worn tracks. Therefore, material removal rates up to 8mm at gauge corner in one working pass were reached.

Processing of new tracks (removal of mill scale)

The machines are also suitable for removal of mill scale whereby removal rates of 0.3mm on running surfaces are required. Processing speeds up to 1.200 metres finished track per hour can be reached.

Processing of high-speed lines

For high-speed lines, the high productivity and extraordinary processing precision of the SF 03 is particularly required. Over short spaces of time and during tight track possessions the precise rail reprofiling has to be gained. For high-speed lines, after the reprofiling process is complete, the track must be free of any grinding and milling residue; for ballast less track it can nearly be ‘clinically clean’.

Noise reduction in specifically observed track

In residential areas, the sound protection has to be below the required or fixed values. As it is pointed out with the designation ‘specifically monitored track’, such track sections are under special control. Through and after its processing waves, corrugations and running surface roughness should have such quality to follow the emission rates fixed by the EBA (German Federal Railway Authority).

Mainline, switch and crossing processing

The new design of the working units combined with new control systems allow more applications of the technology. The newly released rail milling train versions are also capable of processing switch and crossings according to European track maintenance standards.

Rail-Milling Train SF 03

The standard rail milling trains of Linsinger Maschinenbau GmbH are designed and manufactured for world-wide railway systems as the train configuration can be applied to the requirements of any railway system in the world.

The gauge of the rail milling trains can be designed and manufactured from narrow to standard and also wide gauge according to customer requirements.

The advantages of the SF 03 FFS milling train are:

• Railway approved and permitted
• High capacity
• Continuous operation through system autonomy
• Capable for high speed lines
• High planning reliability
• Customer specific design
• Equipment according to need and requirement
• Modular configuration
• Mainline, switch and crossing processing
• Machine-integrated measuring devices for measuring of rail during processing

Rail-Milling Train SF 01

The application of the Rail Milling Train SF 01 is in light rail systems such as metros and tramways.

The advantages of this light version of a milling train are:

• Small structure gauge
• Tight curve radius
• Low axle load
• Dust and spark free operation
• No additional track cleaning works required
• Customer specific design
• Equipment according to need and requirement
• Modular configuration
• Tunnel approved
• Machine-integrated measuring devices for measuring of rail during processing

Rail-Road Milling Truck

The application of the Rail-Road Milling Truck SF 01 is universal in its application for railways as well as in light rail systems such as metros and tramway networks.

This Rail-Road Vehicle moves on rail as well as on road with very high mobility and flexibility.

The Rail-Road-Milling Truck works flexibly in its operations on almost all types of tracks.

The advantages of this light version of a milling train are:

• Small structure gauge
• Tight curve radius
• Low axle load
• Dust and spark free operation
• No additional track cleaning works required
• Customer specific design
• Equipment according to need and requirement
• Modular configuration
• Tunnel approved
• Gauge convertible

The advantages of the Linsinger rail milling technology

Linsinger rail milling technology processes the complete rail surface in one working pass. Operations are environmentally friendly, with no dust or dirt particles. There are no risks of flying sparks or of fire and operations are carried out safely and smoothly. Machines are used all year-round and there are no restrictions for operations. During dry processing, no cooling agents are required. The machines offer very high output (processing possible up to 300m/shift) with metal removal rates from 0.1 up to 3mm from top rail surfaces. Material removal rates are from 5mm at gauge corner areas (up to 8mm at narrow gauge correction works). The machines work with reduced noise and operate at working speeds of 300-1200m/h. Other advantages include:

• Restoration of any required transverse profile possible
• High surface quality with very low surface roughness 3-5 μm
• Clearance free operation of the working units
• Very low tool costs by multiple use of operated tools
• Very low total costs of the equipment

Experience of Linsinger rail milling on European railways

Already after first practical experiences the analysis of the processing system has shown excellent results: The Linsinger milling technology in operation achieves transverse profile tolerances of 0.2mm.

The required longitudinal profile accuracies are:

• From ±0.01mm in area of wave lengths 30-100mm
• ±0.03mm in area of wave lengths 100-300mm
• ±0.1mm up to wave length 1000mm

These figures are requirements for high-speed lines with travel speeds over 280km/h.

These standards are obtained with the Linsinger milling-grinding-principle with an amazing and incomparable perfection.

The limit figures for surface quality are at maximum 10 μm surface roughness.

The Linsinger milling system guarantees values from 3-5 μm and by that sophisticated values for reducing noise level and protracting the generation of wear.

Integrating milling and grinding functions in a single machine offers benefits from an environmental point of view. No environmentally invasive dust is produced during the milling operation. All scrap metal chips as a result of the milling process are collected in a specially designed waste box and can be safely unloaded onto standard railway wagons using a conveyer belt mechanism. Requisite rates of removal during the subsequent grinding process are low. The contact pressure of the grinders is correspondingly low.

Flying sparks can thus be categorically ruled out, whilst dust formation is reduced to a minimum and any that does arise is additionally absorbed by means of an extractor.

Summary

Milling and grinding in a single operation – The new dimension for railway and light rail systems

Using the new technique from Linsinger Maschinenbau from Upper Austria, the railways as end-user have made a quantum leap in innovative rail treatment.

By combining rail milling and grinding in a single operation with a high degree of accuracy and extended conditions of use, a significant reduction in maintenance costs and life-cycle costs can be achieved.

The new application of the milling technology, plus adding the switch and crossing processing ability to the Linsinger standard fleet programme, allows the end-users – such as railway and light rail systems – to use one machine configuration for all necessary track work treatments in the area of rail-profiling such as mainline, switch and crossing maintenance.

Targets to be achieved by use of the Linsinger rail milling technology

The following points are all targets which can be achieved by using Linsinger rail milling technology:

• Increase of the life-cycle of the rail up to 300%
• Reduction of wear up to 95%
• Improvement of the wheel – rail geometry and running behaviour
• Reduction of travel noise
• Increase of travel comfort and travel security
• Improvement of the longitudinal and transverse rail profile
• Reduction of maintenance costs and life-cycle-costs