//Hi-Rail Grinding Machines

The Rhomberg Sersa Rail Grinder, short “GRAIL1”, is a road/rail compact size grinding machine for use in public transport networks.
General purpose of the grinding unit is grinding of main tracks as well as certain areas of turnouts with rotating stones, contact grinding and removal of corrugation (short wave corrugation) and particular defects such as squats, head checks and pitting’s. It is possible to treat Vignol rails of different strength classes. Furthermore grooved rails may be treated as well. The grinding process works entirely without water.

The machine was designed in a manner to be small and flexible, to be transported easily and bear special advantages on low maintenance costs, simple operation, high reliability and grinding quality.

The machine disposes of a grinding carriage with 4 wheels that may be lowered hydraulically. This lowering will lift the complete truck. To propel forward on rail, the rear rubber tyres are pressed onto the rail pneumatically. The carriage consists of 2 frame halves that can be spread pneumatically.

This is necessary to adapt to different track gauges and to spread the rail wheels against the rail while grinding. While spreading and changing the gauge, the rail wheels and gear boxes will slide on the axles.
On rail, the grinder is driven by a frequency-controlled air cooled motor working on the rear road axle gearbox. The driving speed can be adjusted from a touch panel while grinding or by a foot pedal from inside the cabin.

The grinding stones are designed to remove up to 0.8mm corrugation accuracy in straightness and profile ensuring excellent surface quality results. The machine has the capability to grind in both directions and the ability to grind expansion joints and switches & crossings (S&C) to certain extents. The Grail1 is equipped for low noise emissions for night work in urbanised areas. Noise level is less than 75 db(A) at 1 m (70 db(A) @ 7 m) and further diminishing at larger distances.

Average removal rate for one grinding pass can remove from 0.1mm up to 0.4mm (0 – 1/64 inches) short wave length corrugation with a 20mm facet with no “blue steel” resulting. Maximum removal in one pass up to 0.8mm.

Pre & Post grinding measurements are taken to provide the client with an asset record and for future condition based maintenance planning.

Around the carriage, there is a housing to protect machine and operators against sparks and bursting stones. The grinding dust is sucked in by a fan. Filters to extract the dust particles are placed above the truck frame. The cartridges are cleansed automatically by air. The dust collection system is equipped with a fire extinguishing system to increase the working security.
The rail sections in front and behind the machine are watched by camera systems. For safety, there is a light chevron on the back side of the machine, rotating flashlights and a rail lighting set.