Re: Cleaning Ballast - Why do they need to do this?

["Stephen Devenish" <JohnnyR@bigpond.com>]

Reuben Farrelly wrote in message <7q0uf8$l4k$1@eplet.mira.net>...
>What exactly does the cleaning process involve in terms of what does the
>cleaning machinery actually do?  Would I be right in guessing that it
>essentially involves picking up the ballast and tossing it about, so that
>the finer particles are moved nearer to the base, or does it involve
somehow
>removing the junk from the tracks completely?  Track maintenance gangs seem
>to work with a fleet of several vehicles when they are doing work, what
does
>each one do?


Ballast Cleaning can be done a number of ways, depending on the costs and
time allotted to do the work.  Ballast Cleaners are one of the largest track
machines around and consist of a ballast cutting chain and elevating
conveyors.  The cutting chain cuts out the ballast under the sleeper down to
the required depth and removes the fowled ballast from the track.  New
ballast is placed in, the track tamped and lines and then back to running
trains.  Fowled ballast is either dumped off to the side or collected and
either screened or dumped (dependent on cost).

Another method is the poor mans method of actuall removing the track panels
and excavating out the fowled ballast and replacing new ballast and track
panels.  This method is better for tight situations where the ballast
cleaner cannot get in or under turnouts.  We (John Holland Rail) will be
using this method to clean out the pit roads at Broadmeadows next year,
included in the works are the cleaning of ballast under the up end siding
turnout (A Siding).  As was discussed by others, new drainage will be apart
of the works to ensure that it lasts.

One other small point, when installing concrete sleepers, some machines have
the ability to actually cut the ballast away to ensure a good bed for the
concrete sleepers.  The Fairmont Tamper Pony P811 (which both Barclay's and
John Holland use) has a large ballast chain with adjustable depth, this
allows us to cut away fowled ballast and lay the sleepers on a flat bed.
Extra ballast is added to increase the depth and bring the track up to the
old level or higher.  Although this is not ture ballst cleaning, it can
provide a better quality of track than just puting the sleepers in on
existing ballast.  A note for SA residents, the PONY will be resleepering
the suburban lines near the harbour in about 6-8weeks, crab a camera and
enjoy.

>As for weeds, well...a good example of weeds is on the Bendigo line, on the
>up track at St. Albans Station.  Perhaps they are planning on harvesting
the
>seeds? ;)
>
>Reuben

Weeds, better to walk on than fresh ballast, crappy for drainage, extra
maintenance, generally should be taken care of by weed spraying rather than
ballast cleaning.  Due to its high cost ($1000 m I think but don't quote me)
ballast cleaning is only undertaken where major problems occur on high
volume lines (ie MET trackage)


Cheers

Stephen Devenish

"Still welding towards Geelong"



>Bill <wguest@xtra.co.nz> wrote in message
>37C3E246.5D040FE4@xtra.co.nz">news:37C3E246.5D040FE4@xtra.co.nz...
>> Ballast cleaning (as distinct from simply putting new ballast under the
>> sleepers) is done to remove some of the fine and dirty material from
under
>> the sleepers, thus lowering the track. By dirty material, I mean silts
and
>> organic soil; by fines I mean degraded ballast that is less than 25 mm.
>Fine
>> and dirty material does not support the track well, and encourages the
>> growth of weeds that hasten the degradation of ballast and timber
>sleepers..
>
>
>