With the development nearly complete on our impending HO Timber Road Bridge Range, there is one facet that needs sorting & I pose this question regarding double track road overbridges. What track centres do Australian Outline layout builders try to adopt???
This will help in determining the tolerance we use for pile or bent centres both in practice & instruction sheets etc..
While we are aware of NSWGR ruling structure clearances & have perused the NMRA standards, I am not sure whether these hold true in scale practice. Also there are other factors including, rollingstock used, curve radius used ( if applicable ), & of course the existing layout track centres.
Any input would obviously be helpful in determining the best solve to the problem.
For any info on the bridge range please refer to our blog...http://southernline.blogspot.com.au/
Thanks & Regards,
Laser Rail Bits
This could be a can of worms in many ways. So, railway terms for the distance between tracks were called the 6 foot, that is the distance between the outer rail to the inner rail of the other track, the thing whether it was a true 6 foot or not is not known by me.
As for operating should something happen to a train on double track the fireman was always required to walk on the drivers side of the track for any problems owing to the short space between the two down & up main lines. If, the walkway on the drivers side was narrow or littered with debri, usually sleepers or fallen trees, rock etc, to walk in the 6 foot was a last resort.
If a train was heard coming in the opposite direction we were to go flat on the ground in the middle of the 6ft, this was deemed sufficient space for safety, it also fitted in with loading gauges.
As for modelling, how many will have the same distances as others?