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A panel timber door is constructed of stiles (vertical pieces of timber) and rails (horizontal pieces of timber) that frame around panels (thinner sheets of timber).
yes
They're called taff rails, especially at the stern of the ship
the stiles are vertical and the rails are horizontal, in other words, the stiles are the side pieces and the rails are the cross pieces
The inside rails inside of the main rails are called guard rails. They are there so that if there is a derailment the train will stay within the rails instead of off of the trestle.
alfred l cralle
2 running rails. There may be a power rail ("the third rail") There may be guard rails at places like bridges and curves (there always are short ones at turnouts ("switches").
In most areas it is 40 inches
they are there so when the sow rolls over, she doesn't accidentally squish the piglets
The danger and chance of off road collisions, amount of traffic, and the cost to put them in.