Q On the front of a typical diesel locomotive are six “hoses.” Please define their purpose. Further, above the coupler is what appears to be a shorting hose. What is that? – Howard Beard, New Port Richey, Fla. A What you’re seeing is two sets of three hoses that are part of a train’s air-brake […]
Train Topic: Railroad Operations
Ask Trains from May 2008
Q As a boy, I used to watch the magnificent Southern Pacific cab-forward steam locomotives on their way to Donner Summit in Northern California. Someone referred to them as Mallets. What’s the true definition of a Mallet? — C.W. Haffey, Bakersfield, Calif. A By definition, a Mallet (mal-LAY) is an articulated, meaning the two engine […]
CTC: Remotely directing the movement of trains
Who controls the movement of the trains after the tower is closed? The train dispatcher is the most common heir to the towerman’s duties, but not always. The type of control used depends on the nature and density of the rail traffic handled at the location. Ways to preventing trains from colliding when railroad lines […]
Defect detectors
An Amtrak train en route from Milwaukee to Chicago on Canadian Pacific’s double-track main line hurtles by a metal cabin and some trackside apparatus. Over the radio, a stilted voice intones “CP detector, milepost five seven point six. Main track: two. Total axles: one six. No defects. Temperature: five three degrees. Detector out.” A moment […]
Introducing the horn section
Leslie and Nathan may sound like a dull couple from the ‘burbs, but they’re actually the first chairs in railroading’s horn section. The diesel locomotive horn section, that is. Many of today’s train-watchers recognize a railroad by the sound of its diesels’ horns. It’s only natural since sound is a strong memory-jogging sense, second only […]
Mountain railroading terminology
Ruling Grade: The maximum meaningful grade on a line; the grade that limits train tonnage. Traditionally, a ruling grade was the grade up which the standard road locomotive assigned to that division could just stagger with a maximum-tonnage train. This grade may not have been the steepest on the division, however. There may have been […]
Rack and cable railways
Virtually all the railways in the world employ the same system for moving the vehicles that travel over them: Power is applied to some or all of the wheels that support and guide the vehicle along the rails. Adhesion between the wheels and running rails then allows the vehicle to move along the track, often […]
Railroad’s traffic control systems
Traffic control systems Running a safe operation is not as simple as you might think. Every train must have authority to occupy the main track before it can begin moving. There are several types of authorities, but usually only one type is in effect on any given piece of track. Maintenance people must also have […]
Trackage and haulage rights
Because shippers’ distribution patterns are rarely congruent with any one rail carrier, railroads have developed two traditional methods of extending their reach over each others’ lines. The first is the joint rate and route. Two railroads, by agreement, establish one rate from an origin on the first to a destination on the second. One of […]
Selling the service
In the days before airlines and interstates began siphoning off rail freight and passenger business – and big railroads merged to form today’s even bigger mega-systems – virtually every large city and town was served by multiple railroads. Shippers had their choice of carriers to move goods between Points A and B. Passengers, too, had […]
