N
Narrow Gauge	Track with a gauge less than 4 feet 8 1/2 inches.
National Transportation Safety Board	(NTSB) An independent federal agency that investigates serious railroad accidents as well as those in other modes of transportation, conducts special investigation and safety studies, and issues safety recommendations to prevent future accidents.
Navvy	RR construction workers who "navigated" (roamed) from job to job. (plural is navvies).
NEC	North-East Corridor. The Amtrak route with intensive passenger traffic that connects Washington, DC, Philadelphia, New York City, and Boston.
NEM Standard	A series of European Standards.
Net Ton Mile	Moving one ton of freight the distance of one mile.
News Butcher	Peddler who sells magazines, candy, fruit, 'etc., in trains. Usually employed nowadays by Union News Co.
Nickel Grabber	Streetcar conductor.
Nipping	Supporting the tie while another track worker drives spikes.
NMRA	National Model Railroad Association. The NMRA helps to promote the hobby, establish standards, reward modelers for their talents as Master Model Railroaders, and much more.
NMRA Standards	[MR] A model built using NMRA standards where applicable.
No Bill	Nonunion or nonbrotherhood railroad worker. Also called nonair.
NORAC	The Northeast Operating Rules Advisory Committee, whose rulebook is used by most railroads in the northeastern U.S.
Normal	Usual position of points or signals before action initiated by signalman to allow a train movement.
Normal Gradient	The condition that exists when the air brake system is fully charged and there is no difference in air pressure between the front and back ends the train.
Nose	Front end of locomotive.
Nose On	Couple on with head end of engine.
Nose Suspended Motor	A traction motor mounted on bearings on an axle that is driven via a flexible connection attached to a cross member on the truck. The gear on the axle is in constant mesh with the pinion on the armature shaft.
Nosebag	Lunch carried to work. Put on the nosebag means to eat a meal.
NRHS	National Railway Historical Society.
NTSB	See National Transportation Safety Board.
Number Dummy	Yard clerk or car clerk. Also called number grabber.
Nut Splitter or Nut Buster	Machinist.