Why does a steam locomotive chug

At the end of the piston stroke, an exhaust port opens, allowing the steam to escape. Then the process is reversed and repeated in the opposite direction. Steam is admitted to either side of the piston so that it is always under power. A lever in the cab allows the engineer to control the action of the piston valves direction of locomotive movement, and timing. The pistons push or pull the rods connected to the drive wheels, providing the force needed to move the locomotive. The steam is exhausted through a nozzle and up through the smokebox into the stack.

A draft or vacuum results, pulling air through the firebox grates to induce combustion of the coal. Both exhausted steam and coal smoke travel up through the stack. Pull the lever to into the piece and for a couple of minutes in a "truckin' shot" from a car on the adjacent highway, you see one of these mikes doing what it was built for and operated in the manner that kept the railroads running back in the day.

No steam is even seen! The smoke is just dark and thin until they realize this is a for the camera run they lightly choke off the draft and the smoke goes dark, but still not voluminous.

Too much of this carried on for too long while on the move and the fire suffers as does steaming pressure. Of course the fireman is stuffing in fresh coal and that explains a bit too. The coal dust and "fines" thrown in with the lumps, flash burn and even with the same draft, the smoke goes dark.

Can't tell here for sure. A steam locomotive engineer had two controls over engine speed - the throttle and the cutoff. The cutoff, or valve timing, is part of the reverse control generally poser assisted in more modern engines. When this happens, there is very high pressure as the valve opens for the exhaust, producing a barking sound. Once a train was in motion, the engineer could lower the cutoff.

This gave the steam more time to expand, gaining efficiency, and produced a gentler exhaust noise - more a chuff than a bark. Climbing a grade could result in the need to raise the cutoff back and also produce the barking exhaust of a steam engine under load. The cylinder exhausts came together in a blast tube inside the smokebox, some distance below the stack opening. The venturi effect provides the necessary draft for the fire. When the locomotive stops, there are no more exhaust pulses to supply the draft, and the fireman would have to activate the "blower", a smaller jet pipe fed by the boiler.

The figure I heard for a ruptured crown sheet in a psi boiler with degree water at that pressure was to 1 - each cubic foot of water released to atmosphere would instantly become cubic feet of steam with disastrous results for locomotive and crew.

Every so often someone mentions it in a post, but I can't find hide nor hair of it on my cable system as an offering. Is it only available in certain areas, or only on satellite or?? Home » Model Railroader » Forums » Prototype information for the modeler » steam engine "chugs". Order Ascending Order Descending. Member since March From: wisconsin rapids, wi posts. Posted by ratdogsoo on Monday, May 14, PM.

Member since February From: Northview, Missouri posts. To break your question into pieces: "Chugs" - each one is the exhaust event from one end of one cylinder. Chuck Modeling Central Japan in September, - where steam locos burned poor quality coal. Paul 12, posts. Posted by wjstix on Monday, May 14, PM. Member since July From: somerset, nj 3, posts. Posted by gregc on Monday, May 14, PM. Posted by wjstix on Tuesday, May 15, AM. Train Modeler.

Member since March From: South Carolina 1, posts. Sometimes they seem to bark. Posted by selector on Tuesday, May 15, AM. Member since May From: Dunlap, Tn. Thanks to the rest of the group for the information.

Posted by ratdogsoo on Tuesday, May 15, PM. Posted by gregc on Wednesday, May 16, PM. Member since July 3, posts. Posted by locoi1sa on Wednesday, May 16, PM. I pray every day I break even, Cause I can really use the money! I started with nothing and still have most of it left!

Member since August posts. Posted by narrow gauge nuclear on Friday, May 18, PM. Richard If I can't fix it, I can fix it so it can't be fixed. Excessive use of cylinder petcocks "Three or four turns of the drivers should be sufficient to clear cylinders of condensation.

Chuck Modeling Central Japan in September, Member since July posts. Posted by wjstix on Friday, May 25, AM. Member since December posts. Users Online There are no community member online. Search the Community. Model Railroader Newsletter See all. Sign up for our FREE e-newsletter and get model railroad news in your inbox!

Sign up. The water that makes the steam either comes from tanks mounted on the side of the locomotive or from a separate wagon called a tender, pulled behind the locomotive. The tender also carries the locomotive's supply of coal. What color is coal smoke? Re: Color of smoke Black and grey indicates unspent fuel such as coal or oil.

Brown is poor grade coal or oil or is wood smoke. White is simply steam condensing in the cooler air. Blue smoke indicates the fire is out. When were steam locomotives phased? Steam wasn't systematically phased out in the U. Today, there is still one steam locomotive operating on a Class I railroad in the U.

For the most part, though, the U. How hot is a steam engine firebox? What is the front of a steam engine called? In railroading, the pilot also known as a cowcatcher, cattle catcher or cow plow is the device mounted at the front of a locomotive to deflect obstacles on the track that might otherwise derail the train.

Instead of a pilot, trams use a device called a fender. What are train parts called? A train can consist of a combination of one or more locomotives and attached railroad cars, or a self-propelled multiple unit, or occasionally a single or articulated powered coach called a railcar.

A passenger train consists of one or more locomotives and usually several coaches. Did steam engines cause pollution? The most direct pollution problem created by the locomotive was the carbon dioxide emitted into the atmosphere.