How a train maintains balance on track and not creating noise when the wheels move over the iron rail?

Question

How a train maintains balance on track and not creating noise when the wheels move over the iron rail?

Answer 1

A great and informative answer by HOGHEAD! He covered it all.

I will add the reason rail was manufactured at one time in 39' sections so it would fit in railroad's 40' gondolas, believe it or not. It was easy to transport that way for maintenance forces. Also, it wasn't uncommon to find it re-used, cut in 33' sections. The first 3 feet on each end of jointed rail received the most wear, but the center could be re-used - workers would cut 3 feet off each end, leaving a suitable 33 foot section for reuse (on less-used tracks).

Also harmonic rocking is a problem on jointed rail. It has caused derailments - at around 15mph as HOGHEAD stated it gets to a breaking point where trains would rock themselves off the rail. As I recall, the instruction was to keep it 12 and under or 20 and above to avoid this problem on jointed rail. I've felt it before and it starts to get a little scarey when you feel the harmonic rocking going until you gain more speed. A tourist line/small time carrier I volunteer for moves along at about 20+mph over jointed rail...

Answer 2

I could not have said it better than what HOGHEAD did.  I work for a railroad now but he said better than I could have ever told you.  Listen to what he says.

Answer 3

if you examine a train's wheels they have a flange that goes down the side of the rail. that is why they stay on track.Have a look at a childs trainset and you will see it clearly

Answer 4

The answer above is correct.  The flanges on the insides of the wheels keep the equipment on the rail as well as "steering" the trucks of the car or engine.

The old "clickety-clack" of the equipment is absent due to advances in technology.

At one time, railroad rail was manufactured in 39' lengths (and later in 78' lengths) and when laid were joined together with an "angle bar", which is a coupling device that fits into the "web" of the rail, which is the thinner upright portion of the rail between the base of the rail and the top, or "head" of the rail.

These were bolted in place.  There was always a gap between the two sections of the rail that had been joined, and when the wheels passed over the joint, presto!  Clickety-clack.

These days, except for sidings, secondary main and yard tracks, almost all main line track is ribbon rail.  Ribbon rail is manufactured in 1320' (1/4 mile) sections and loaded on to a special train designed for the purpose of transporting and distributing the rail where needed.

When installed, the joints between the sections are welded together, and form what is now called CWR, or continuous welded rail.  This was done because where the joints exist, additional wear and tear occurs over time, requiring grinding or other maintenance.

Your choice of the word "balance" in your question is interesting, because jointed rail did cause balance problems in the form of a phenomenon called "harmonic roll".  Where the joints in the rail existed there was "give" in the structure, even when the joints were directly over a cross tie.  As the car moves along, each time it passes over a joint, it will dip to that side, then to the opposite side at the next joint, setting up a roll to the equipment.  This interaction was most severe at a speed of 15 miles per hour, a speed that engineer's were instructed to avoid, if possible.

Since these improvements to track and structure, unless the wheels of the equipment have flat spots, they move along in near silence.  Which is what makes them even more dangerous.  They can sneak up on someone walking along the tracks, so, the best advice is to not walk along the tracks.  If you must, then keep an eye out for that which may be right behind you.  Sometimes, when ribbon rail is worn out, it is re-laid as part of a secondary or yard track.  Again, this is an area where one can expect a single car to be rolling on its own, silently creeping up behind you.  Stay alert and stay alive.

Addendum:  For alvassar 1980, "Da Ace" and Sergie l.  Thank you for your kind words.  I must defer to "Da Ace" here, because I was educated by his answer.  Long had I wondered, "Why 39 feet?"  I now have an answer.  Thanks "Ace", and you get the vote for best answer!!

Answer 5

Hoghead is perfectly correct. Hm M.O.W. guy? Must be. Also most in city rail lines we are now building w/o joints. Seamless rail, people who live close to in-city rail lines do hate that clickety-clack.