On 8/06/2018 11:02 AM, David McLoughlin wrote:
> The Sydney Light Rail folk posted this on their FB page:
> "The Queens Birthday long weekend is fast approaching, and there’ll be extra cause for excitement in Moore Park with track and rail being laid across the Anzac Parade / Dacey Avenue / Alison Road intersection."
> Wondering about their use of "track and rail" for what was obviously the same thing, I posted this comment:
> "What is the difference between "track" and "rail" ? Surely they are the same thing in this context. The rails are for the tram track. The rails once laid *are* the tram tracks."
> To which they replied by FB Messenger (not on the page post):
> "Hi David, good question! The difference between rail and track seems to be confusing as essenitally they're used in same context. However, best way I can differentiate is ;A rail consists of two parallel steel or iron rails that are set at fixed distance to each other, called as gauge. The rails are connected to each other by railroad ties, can be of concrete or wood which typically makes up the track which the tram will run along. Hope this helps. Thanks, M"
> Does this make any sense to anyone at all?
Whatever they are trying to say, it is technically wrong for the Sydney project.
The (uber expensive!) system used in Sydney completely dispenses with "ties" - which we call sleepers.
(It sounds like they referred to an American source).
All the CSELR is (as far as I know) based on a solid concrete slab with channels cast into it.
The rails are encased in insulation and dropped into the channels.
You can see this in Matthew G's pic at: http://tdu.to/i/60427
It's all about avoiding electrolysis currents by keeping the rails electrically isolated from the ground, as well as providing some 'give' in the rail to avoid excessive noise.
Mal Rowe in a city saving a lot of money by mitigating electrolysis instead of trying to avoid it.