What's the purpose of the rails in the middle?

They are called "Guard Rails."

 

They are placed at locations like bridges so that if a wheel derails, the guard rails will keep the car on the right of way and prevent it from crashing into the side of the bridge.

I thought I saw this picture a bit ago... Was it two narrow gauge tracks that merge with each other for bridge clearance?

No...just guard rails. Note how rusty the guard rails are. There have not been any wheels on those rails for years...just the way it is supposed to be!

There was a double track system usually on bridges that used a single, center, common rail for both sets tracks. I believe it was called a gauntlet or gantlet. 

Recently I posted some information about the New Haven RR bridge over the Hudson River, Poughkeepsie, NY.  At one time it had a gauntlet to allow better weight distribution on the bridge.   

Thanks Rich. This bridge is near San Luis Obispo, CA and was scouting it last night for adding a bridge on my layout and saw these rails. The guard rails make sense as they are bent in to a point just past the ends of the bridge..

This is NOT a Gauntlet Track. That is a totally different setup and would have four rails. Again, note that the guard rails are all rusty. Rusty rails = no wheels rolling over them.

 

They are just guard rails.

 

A gauntlet track has nothing to do with weight distribution.  I's all about getting two tracks through where there's only room for one.

 

Rusty

 

From the Wikipedia Poughkeepsie Bridge  link. "The bridge was strengthened in 1912 by engineer Ralph Modjeski, of famed bridge civil engineering firm Modjeski and Masters, by adding a third line of trusses down the middle and by adding a central girder and additional interleaved columns, to safely handle the increased weight of freight trains crossing it, as can be seen in this illustration from the Poughkeepsie Journal story archive. In 1917-18, the double tracks on the bridge were converted to gauntlet track operation to center the weight of new, far-heavier New York, New Haven and Hartford Railroad 2-10-2 steam locomotives. The gantlet tracks were replaced by a centered single track in 1959"

 

 

I ask a railroad engineer, not the one who operates the power units, about the additional rails laid on bridges, thinking, as has been mentioned that they were guard or guide rails as a safety feature for de-rail.  He told me the additional rail is to help inhibit lateral force (side ways motion) on the bridges.  Most of a bridge strength is designed end to end with forces transferred to the footings piers.  Sideways motion to a lesser degree is incidental, but as weight and sized increased it becomes an issue also.  IMO.  I would need some verification on this.  Mike. 

 

That would be four lines there (first rail and third, second rail and fourth, thrird rail and fifth, fourth rail and sixth).

Fellas! Fellas!

 

The OP asked about the extra rails in the middle! Let's not go off on a tangent about other things that have absolutely nothing to do with the OP's original question!

Every bridge and even some culverts use to have guard rails.  I note that guard rails have disappeared in recent times.  Do railroads now have the confidence that trains will not derail on bridges?

Kent,

Sometimes if you do not see guard rails, you will see ties bolted lengthwise along the ends of the bridge ties (the bridge ties being longer than a normal tie). During bridge tie replacement, a slow order will be in effect from the time these guard ties (so to speak) are removed until they are replaced.

Rich, this question may strike you as completely foolish, but it's something that has bothered me for a long time.  I have heard this explanation of guard rails, but I just don't get HOW it actually accomplishes that.  

 

Are you saying that, in the photo that Roman provided, if the wheel running on the outside (leftmost) rail derails to the inside of the rail, the inside (flange) side of the wheel will rub up against the guard rail thus limiting the train's ability to drift further to the right?  Don't the wheels on the other side of the train already serve that function?

 

Same thing about the "guard rails" on my tinplate switches:  I don't see how they help, seems like the thing would work just as well without them.

 

When I was a kid I asked my parents why highway guardrails were called that, when they were really fences, not rails at all.  They looked at me the way you look at a kid who is asking too many "why?" questions.  Since trains predated cars, and since the purpose seems to be the same (to keep the vehicle on the right-of-way), were highway guardrails named after real (railroad) guard rails?

 

The answers to life's most persistent questions...

 

perhaps being in CA they are merely there to strengthen the bridge.

those inside rails are much too widely spaced from the active rails to be effective as guardrails.

For clarification: The wide guard rails on bridges were merely to prevent bridge damage from cars that had ALREADY derailed.  The close-up guard rails on curves and switches are intended to act on the inside of wheel flanges and PREVENT derailments.

I believe it is Gantlet.  I don't know what a Gauntlet is, but that is what you throw down when you want to fight somebody.

Actually GANTLET is the original spelling of the word.  GAUNTLET came later and has several of its own definitions.  Remember what's his name in that movie "The Gauntlet".

 

Rick

Good grief!

So about them guard rails.........

 

Chris

"guard rails" are designed to keep derailed cars from wandering askew and striking the bridge's vertical members. They also serve to keep derailed trains from falling off deck bridges and such. They are an imperfect safeguard, but it probably considered better than nothing.

   A gantlet track is, as has been said, where two tracks are overlapped to save side-to-side space in narrow ROW situations (tunnels, narrow corridors, bridges, etc). They are often accompanied by signals at each end to guard against two trains occupying the gantlet sections.

   A "gauntlet" is a large heavy glove worn as protection in jousting or battles involving swords and such (hence the phrase "throwing down the gauntlet" meaning a challenge). Also refers to heavy gloves worn to protect hands when working with fire, fireplaces, molten metals, etc.

 

"Guide rails" (often called guard rails) are those on switch tracks which help guide the wheel flanges through frogs to keep them from "pecking" and hitching on the frog point or other sharp part, thus helping eliminating the wheel from lifting up and derailing.

 

~Andy

 

RIP, Joe G

From Model Railroader magazine, April 1948.  Looks like gauntlet to me:

Image: c Kalmbach Publishing Co.

 

Rusty

And you think no one reads this stuff.  Who Knew???  I was riding my bike across the Hudson, rainy day, on the Poughkeepsee bridge thinking this a bit narrow for two tracks.  Please enjoy the Walkway over the Hudson if in the area, we spent 26 million on the project.  New York State Park. 

http://grammarist.com/usage/gantlet-gauntlet/

Originally posted by hojack:

Are you saying that, in the photo that Roman provided, if the wheel running on the outside (leftmost) rail derails to the inside of the rail, the inside (flange) side of the wheel will rub up against the guard rail thus limiting the train's ability to drift further to the right?  Don't the wheels on the other side of the train already serve that function?

NO because the wheels are on a fixed point on the axle. The "other wheel" derailed on the outside of the track guage will have nothing to stop it for continuously moving sideways until one of the wheels hit something. Thus the purpose of the Guardrail where the wheel derailed inbetween the rails will hit and preventing the derailed car from moving furthur sideways.

I added O scale Guardrails to my Atlas O bridge. Makes a unique and nice detail to an already detailed bridge.

Guys

 

I think we all know it is to provide power to the pick up rollers under the locomotive.  Geeze get it right!

 

[VBG] = Very Big Grin.  OK, my tongue is out of my cheek!

its prototypical to Lionel track,

its the center pick up rail for power.