G'Day,
I found a very interesting video on Track gauge. It is Canadian, & follows NMRA HO standards. See Track Video.
This is something I urge everyone to watch. It graphically shows the relationship between the critical parts of a set of points & wheels.
Apart from Modelers, I believe manufacturers staff should look at this too.
The video is produced by Tim Warris; who proved derailments can be a thing of the past - See Tilt Table.
He only stopped after 50,000 perfect cycles because the Train show staff wanted to close the show & go home. :)
Track Video
http://www.handlaidtrack.com/nmra-online.php
Tilt Table Video
http://www.bronx-terminal.com/index.php?s=tilt+table
Mark,
Yes, that is a great reference and good info. One of the modelers in our group has and uses the fast tracks system and I had seen the video some time ago. As a long time modeler who has handlaid quite a bit of track, I was already familiar with this info and have discussed it on this board in the past.
The principles explained in the video are why I do not use any of these new semi scale wheels on my equipment. Anyone who understands how a turnout frog works knows that semi scale narrow wheel treads are a invitation to problems on track built to NMRA standards.
I am sure someone will respond that they have lots of semi scale wheel sets and have no problems - but if they watch/listen as their rolling stock goes through turnouts, every piece with semi scale wheels rocks sidways and "clicks" as the wheel falls into the frog. Not the kind of operation I want.
For me this is an operating hobby - operation comes first - detail second. So I will stay with the proven standards and not try to fix something that is not broke - as the tilt table deminstation shows.
Sheldon
More specifically, the 4-6-0 low boiler is prototypical to the Maryland & Pennsylvania's #27. The high-boilered models are the same basis, with larger drivers and a larger tender.
Phil