Re: Why Wooden Sleepers are better. Was [NSW] CityRail Delays Friday

[Bruce Bellingham <bruce.bellingham@clear.net.nz>]

New Zealand has been using treated pine sleepers on heavily used main
lines for at  least 30 years. These have been either creosote dipped in
early days, or CCA (copper-chrome-arsenic) pressure treated more
recently. The rails are screwed down with screw spikes, or more recently
Pandrol base plates are screwed to the sleepers, then a standard Pandrol
clip used.
Sleeper life is generally at least 15 years, some are now up to 25+.
One advantage over concrete is the performance in  derailments -
concrete shatters readily from an impact which leaves the pine sleepers reusable.


> 
> > Pine sleepers would have to be copper-cyanide treated and the sleeper
> >plates screwed in, not dogged. (And pine plantations are very hard on
> >the soil, causing other soil conservation issues).
> 
> BTW, it's usually copper and arsenic, not copper and cyanide