steam engines and air lines?

[wisandsouthernkid]

do steam engines use an air compressor to pressurize the brakes as diesels do or they use steam pressure (i would assume not being water in the lines causes major problems). or is it run through an air dryer and then pumped into the lines?

[tdmidget]

There is a reason they are called "air brakes".

[marknewton]

That depends on what engines you're asking about, doesn't it?

Most US steam locos were fitted with air compressors to operate the loco and train brakes. Exceptions include the Maine 2-footers, which at one time used Eames vacuum brakes, and some logging and small industrial locos which were only fitted with a steam jamb or brake on the loco itself.

Elsewhere in the world you could find air brakes, vacuum brakes, hand brakes, and rope or cable operated brakes.

Cheers,

Mark.

[DSO17]

     The compressors on steam engines were usually called "air pumps". If you type air pump into the the search box you should come up with a lot of information.

[daveklepper]

They were stean driven, almost always reciprocating.   On some locomotives they were on the smokebox front.   Most often they were on one side, dirctly below the running board.

[dldance]

is it run through an air dryer and then pumped into the lines?

There is no air in steam (or at least there should not be any).  Dry steam is just steam at a sufficiently high tempurature (pressure) that there is not condensable water.  So if you ran steam through a dryer you would cool the steam and get water.

Now back to the point - the replicas at Golden Spike each have a one-lung air pump.  The brakes operate at 90 psi just like modern engines.  We do have to manually oil the air pumps each day of operation.

dd

[THE.RR]

  There were locomotives with steam brakes.  Some mountain railroads in the 1930's or so had some power equiped to put steam into the 'back' side of the cylinder.  The loco drifting down hill would then work against that pressure. Sort of a steam version of dymanic brakes. (Le Chandlier (sp) system).

  Prior to 1900, and air brakes being common on the rolling stock, locomotives could be equiped with a steam cylinder to operate the brake shoes on the drivers.

  Brakes on the cars were always air, lack of air, or Armstrong. 

Phil

[marknewton]

  There were locomotives with steam brakes.  Some mountain railroads in the 1930's or so had some power equiped to put steam into the 'back' side of the cylinder.  The loco drifting down hill would then work against that pressure. Sort of a steam version of dymanic brakes. (Le Chandlier (sp) system).

Le Chatelier. The principle of the Le Chatelier brake is to suck in air during the descent, and to pump it into the steam pipes, where it accumulates and its pressure acts as a brake. The discharge of the air is arranged by a pipe, the valve of which is in the engine cab. The driver regulates the speed of the descent by this valve, which controls the pressure of the compressed air. One problem with this arrangement was the passage of hot air and cinders from the smoke box through the cylinders. To remedy these, le Chatelier arranged that a jet of hot water from the boiler should be delivered into the exhaust pipe, so that steam and not the hot flue gases would be pumped back.

I've worked an engine with Le Chatelier brake - very interesting experience.

  Prior to 1900, and air brakes being common on the rolling stock, locomotives could be equiped with a steam cylinder to operate the brake shoes on the drivers.

  Brakes on the cars were always air, lack of air, or Armstrong. 

Or vacuum.

[erikem]

  Prior to 1900, and air brakes being common on the rolling stock, locomotives could be equiped with a steam cylinder to operate the brake shoes on the drivers.

  Brakes on the cars were always air, lack of air, or Armstrong. 

Or vacuum.

Or Creamer wind-up spring brakes.