[N.S. Rob]

I thought they were 4'. I was wondering if that is too tight for the sd70's or dash 9's. I want to add a siding to my layout and was wondering what switch to buy?  I am currently using all USA brass.

 

[Trains]

They look to be two foot radius, witch is way to small for those engines.

 

[Paul Burch]

Rib,
If you want to run those big modern locos I would go with a minimum #6 turnout.