On 20/07/2017 12:05 PM, 'Dudley Horscroft'transitconsult@... [TramsDownUnder] wrote:
>

> Surely, rather than using short scrubber/grindstones (are they the same or different?) it would be desirable to use stones about one

> metre long so as to ensure that only the tops of the corrugations are removed.

>

Hi Dudley,

The terminology varies from country to country.

It is my understanding that what we call a scrubber is called a grinder in the USA and possibly Europe.

Here's a pic of the Ballarat scrubber at Bylands - with an inset showing the carborundum block that is used to scrub the rails.
http://tdu.to/Ballarat-scrubber-block_Bylands_5Oct2014.JPG
You wll see that the block is sitting on the bumper in the main picture, and is about the size of a house brick.
All it does is clean / smooth the top of the rail.

In Australia, a grinder was more complex - re-profiling the rail head and cutting the groove a bit deeper using grinding wheels.
There's an official pic of one of the big MMTB grinders at: http://tdu.to/a24583/MMTB_report_RailGrinder.jpg

The big Melbourne grinders were based on the Woods-Gilbert design - an early Melbourne designed 'rail planer' that even had a stint of service in the UK.
See: http://tdu.to/130891.msg

See also my earlier posting - with other pictures -at: http://tdu.to/193985.msg

Mal Rowe