Re: SLR - Extension construction

["Bill McNiven" <wmcniven@gunzel.ozemail.com.au>]

C. Dewick wrote in message
>It's definitely not flat. One of the tunnels (not sure which one, but I
>remember that it's nearly straight except for a curve at one end) is a but
>like Scarborough tunnel on the Illawarra line in that it has a very sharp
>grade all the way through the tunnel.

Mmmmmm....

The old NSWGR Curve & Gradient Book shows a ruling grade of 1 in 100 between
Darling Harbour and Wardell Road Junction.  The steepness of the grade in
Glebe tunnel is a sort of optical illusion ... it's 1 in 100 falling from
each end of the tunnel to a low point about 1/3 of the way from the western
end.  So it looks just like going from Level to 1 in 50!

Rgds

Bill