Established in 1959, Stax Records is a label synonymous with “soul” music. In 15 years, Stax had nearly 250 songs chart in the R&B Top 100. A couple of Stax’ recording artists, William Bell and Otis Redding combined to give us an overpowering metaphor for “taking something for granted”; Bell’s 1961 signature song, later recorded by Redding… “You Don’t Miss Your Water (Until the Well Runs Dry)”. Anyone who has driven, piloted, captained, steered or otherwise… motivated a vehicle has probably done so under the soothing illusion that the song alludes to. When we roll up to the intersection in our car, we believe the brakes will work. And, Bell’s metaphorical warning notwithstanding, we are very rarely disappointed. Still, you don’t miss the brakes until….

On the Shiny Irons, this same confidence is warranted. Every day, literally millions of tons of freight roll along the rails, and when the brakes are applied, the train stops! This was not always the case. During the early days of the fledgling industry, the size, weight and speed of trains roared ahead of brake performance. When Peter Cooper tasked his 1830 steam locomotive Tom Thumb in a race against a horse-drawn wagon, both vehicles had very much the same braking technology… which was, more or less, a mixture of force, luck and hope. The technology was usually a mechanical lever connected to some form of friction shoe; when the operator needed to stop, the lever was pulled and the shoe brought into contact with a wheel. As the Iron Horse grew larger and stronger, more wagons could be drawn, which led to the need for increased braking power. The mechanics of the wagon brake were simply multiplied, with a manually operated brake installed on each car. To operate the brakes, workers called brakemen were stationed atop the cars. In common with most of the industries in the early days of mechanization, railroaders worked a very dangerous field. At a signal from the locomotive whistle, the brakemen would turn a hand wheel which applied the friction shoes to the wheels. Each brakeman was responsible for the brakes on two, sometimes three cars, which left the unfortunate operator running along the tops of bouncing, jerking railcars, applying and releasing brakes as required. Needless to say, accidents were common, and a fall from the top of a car was often fatal.

Brakeman on the Roof of a Railcar

Additionally, the systems were terribly inefficient, with limited braking force applied through the vagaries of judgment, speed and strength of the brakemen.

Early on, powered brake systems began to appear on the Irons, such as the steam powered locomotive brake. This system used the locomotive boiler steam to apply brakes to the wheels of the locomotive. While this was a definite improvement, it could only be applied to the locomotive itself. Some form of powered braking for the rest of the train was needed. In 1855, William Loughridge patented a chain brake which offered a continuous braking system running the length of the train. While this finally allowed the brakemen to climb down from their dangerous perch, it was very limited in power, difficult and time-consuming to adjust, and very sensitive to misalignment. The vacuum brake system, and a similar compressed air system, came into vogue next. These used vacuum or compressed air to operate a piston which applied the friction shoe to the wheel. Flexible hoses running between cars carried the vacuum the length of the train. While these systems did allow powered braking to all the cars in the consist, they had several drawbacks, the most serious being that neither system was “fail-safe.” If one of the hoses between cars failed, or was not coupled, the cars “downstream” had no brakes. More critically, in the event of a train break, where a between-car coupler fails, the cars which separated from the train would be free-rolling, with no brakes. Two serious accidents in the U.K. led to new, safer systems being developed.

A devil’s brew of failures in 1876 led to the deaths of 14 in a three-train crash at Abbots Ripton, England. A passenger train was involved in a collision with a coal train, and another passenger train collided with the wreckage. Several factors leading to the crash included signals rendered inoperative by snow, and inadequate braking power available to the trains. In 1889, several cars of a train carrying passengers on a Sunday School excursion was decoupled from its locomotive because the power available was insufficient for an encounter with a steep grade. Blocks were placed behind the wheels of the idle cars, but the weight crushed the blocks and the train rolled down the hill. The resulting crash killed 89 passengers.

These crashes led to the Regulation of Railways Act in Britain.  Some of the measures contained in the Act were;

  • Mandatory introduction of fixed block signalling;
  • Mandatory introduction of interlocking of points and signals;
  • Mandatory introduction of continuous brakes;
  • Creation of the means to finance such measures, by issuing debenture stock;

A stint in the Army during the Civil War impressed young inventor George Westinghouse with the importance of the Shiny Irons to the industrialization of the United States. So much that, in 1869 he developed and patented a compressed air braking system for use on trains. The design was improved in 1872 to become the now familiar triple-valve controlled fail-safe brake system. The innovative design was met with skepticism from railroad management, prompting a now-famous exclamation from Cornelius Vanderbilt, captain of the New York Central Railroad;

As Cornelius “Commodore” Vanderbilt told Westinghouse, “Do you pretend to tell me that you could stop trains with air?

Westinghouse proved his design with a demonstration, equipping a locomotive with an air pump and air tank, and fitting air cylinders and piping on all the cars. A jaunt from Pittsburgh, Pa. to Steubenville, Oh., using only the Westinghouse brake system convinced all concerned of the system’s workability and reliability… all concerned except the railroads. As it happened, the unconvinced parties at the railroads were mostly the “bean counters”, who did not want to spend the considerable sum of money needed to equip all the rolling stock with the new system. Soon, though, new regulations were enacted requiring the use of fail-safe braking systems. When Lorenzo Coffin became Iowa’s first railroad commissioner, he assisted in passing railroad safety mandates, including the first legal requirement for fail-safe train brakes. Following this lead, in 1893 the Railroad Safety Appliance Act was passed by the U.S. Congress and signed into law, mandating the use of fail-safe air brakes.

Though it seems complex, the Westinghouse brake is simple in operation.

Piping diagram for a 1909 Westinghouse 6-ET Air Brake system on a locomotive

The genius of Westinghouse’s system addresses the inherent problem with straight compressed air brakes – if the supply air is lost, Westinghouse’s system still works! The triple-valve is so called because it performs three functions: It charges the air tanks on each car, it applies the brakes, and it releases the brakes. In simple terms, the sequence of events is this;

The engineer applies the brakes by operating the locomotive brake valve. This causes a drop in pressure in the trainline (the trainline is the air line that runs the length of the train consist and carries air to all the cars’ brakes). The pressure drop in the trainline signals each car’s triple-valve to begin feeding air to the car’s brake cylinder from that car’s air reservoir. This will continue until maximum brake cylinder pressure is reached, or until the engineer releases the locomotive brake valve. When the engineer releases the locomotive brake valve, the pressure builds again in the trainline, signaling the triple valves to begin discharging the cars’ brake cylinder air pressure and at the same time begins recharging the cars’ air reservoirs.

The Westinghouse system operates the brakes when a DROP in line pressure is seen in the trainline, instead of operating them by pressurizing the trainline. With this approach, if the train breaks, isolating some of the cars from the locomotive, the trainline air pressure to those cars will quickly drop, and their brakes will automatically be applied by their triple-valves!

The modern application of the fail-safe also has an “emergency” air reservoir on each car which, in the event of a rapid application of brakes, will speed up the application of braking force to the cars’ brake cylinders. Other features allow the air brakes on a car to be manually released in order to to move the car, and allow modulation of the brake pressure if full braking is not needed. In addition to the air brakes, each car has a manually operated mechanical (usually chain-driven) hand brake which can be used when a car is disconnected from locomotive air pressure.

The Irons still see incidents and accidents caused by problems with train brakes, and these are overwhelmingly due to human error rather than mechanical failure. Train brakes today are more than adequate for the task, mechanically sound and simple to maintain, to set up, and to operate, and are extremely reliable. The days of brakemen running the tops of the cars are long gone, and no one misses them! Looking toward the future, the Irons see some new stopping technology on the horizon, including electronically controlled brakes which will eliminate the “lag time” it takes for changes in trainline pressure to make their way to the end of the consist. Also coming is positive train control, an industry-wide control technology which will locate and track all the trains at once, and coordinate their movements to greatly reduce the possibility of collision. This will allow the railroads to move more goods, faster, safer and with more precision.

… and this will keep the rails shiny!!


Little Toy Trains….
Scale model railroading is usually thought of as an aside to the larger railroad industry, however, one of the largest players on the Irons got its start building model trains. A jeweler and silversmith by trade, and an avid tinkerer by disposition, young Mathhias Baldwin would go on to found one of the largest industries of its time.

Baldwin Locomotive Works, circa. 1875

His original stationary engine survives in the Smithsonian Institution in Washington, D. C., and a replica

Replica model of “Old Ironsides” at the Franklin Institute

of his last “toy train” lives in the Franklin Institute Science Museum in Philly.


Play a Train Song….
“Stop That Train”…. Keith and Tex ask for an emergency application of the Westinghouse Air Brake…

from their 1967 album of the same name.

One comment

Leave a Reply

Your email address will not be published. Required fields are marked *