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 Post subject: Re: rails in concrete
PostPosted: Wed Jul 11, 2007 4:56 pm 

Joined: Thu Aug 26, 2004 2:50 pm
Posts: 2815
Location: Northern Illinois
Bill,

Please don't take my comments as criticisms, I was just raising the points because others might be planning floors around track expected to be used by 4-8-4's or whatever. Also from the additional photos it appears that there are more rail "cross ties" than were apparent in the original photo, the riser blocks place more concrete under that rail, and anyway, the whole thing sits on a foundation wall.

However, what about the typical railway museum "greenfield" scenario where the group wants to scrape the grass off a former beanfield, throw down some gravel and some track, and pour a concrete floor? One thing that hasn't been mentioned here is that perhaps some engineering is in order.

I have seen some pretty big engines stored, and moved over, some pretty marginal track; 60# rail skeleton track laid on 6" of gravel, but it is also quite evident that this track has a lot of deflection under the weight. If the track isn't tied solidly to the floor, and the floor slab designed to distribute the weight, it is very likely that the track will go down, but the floor won't.

In addition, the first thing that members are going to want to do with that nice flat concrete floor is place jacks on it. A six inch thick non-reinforced floor slab does not a jacking pad make, unless all we are jacking is limited to trolley cars, freight cars, and small narrow gauge steam locos.

Some forethought really needs to be given to determine both the loads on the rail and the maximum point loads that will be generated by jacks, and the floor designed with those in mind. I realize that concrete is expensive, but the thickness of the slab is rather easy to vary by simply sculpting the grade it is poured on, and reinforcing rod needs to only be placed where the expected loads dictate. Most jacking is done with the jacks within 30" or so of the outside of the rail, and thickening the floor in this area will also benefit the load the track itself can accommodate. The key is identifying the design loads, then getting someone to run the numbers and design an adequate slab.

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 Post subject: Re: rails in concrete
PostPosted: Thu Jul 12, 2007 12:49 pm 

Joined: Tue Aug 24, 2004 2:35 pm
Posts: 419
Location: NJ
I would also consider adding fiber mesh to the concrete mix prior to placing it as a floor. This is nothing more than little fiberglass strands mixed in the conrete batch that will also aid in reinforcing the floor once cured. Its an extra measure worth adding IMHO.

Chris, another civil E that can design any traffic signal you want but has limited floor slab and concrete work experience.


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 Post subject: Re: rails in concrete
PostPosted: Sun Jul 15, 2007 1:45 am 

Thanks. I appreciate the information. The rail as the crosstie and encasing the who mess looks cleanest.


  
 
 Post subject: Re: rails in concrete
PostPosted: Tue Jul 17, 2007 12:16 pm 

Joined: Sun Aug 22, 2004 2:46 pm
Posts: 659
Location: St. Louis, MO
In making plans for a new visitor center which will include an exhibit hall with one track for railroad items we were asked questions that suggest that the firm doing the plans were intending to just put crossties and rail on the concrete floor. Several items in this thread suggest this is a very bad idea. Any specific warnings or experiences that we can have to pass on to these folks would be appreciated, as they seem intent on re-inventing the wheel instead of asking others with real experience how to proceed with the project.


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 Post subject: Re: rails in concrete
PostPosted: Tue Jul 17, 2007 1:31 pm 

Joined: Thu Aug 26, 2004 2:50 pm
Posts: 2815
Location: Northern Illinois
On the concrete floor? And they will deal with the tripping hazard by...?

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 Post subject: Re: rails in concrete
PostPosted: Tue Jul 17, 2007 2:50 pm 

Joined: Sun Aug 22, 2004 10:52 pm
Posts: 337
Location: Las Vegas, NV
Ron Goldfeder wrote:
In making plans for a new visitor center which will include an exhibit hall with one track for railroad items we were asked questions that suggest that the firm doing the plans were intending to just put crossties and rail on the concrete floor. ...


Do you mean to put the completed track panel with the ties resting on the top surface of the concrete? If so, that actually works out OK as long as all the ties are in good condition and are uniform thickness so you distribute the load out evenly. You still have to mitigate the tripping hazards, but if you are using short panels under your equipment, that can be dealt with.

If you are saying that they want to use wood ties and rail and then pour concrete over that, there is noting "wrong" with that. It has been done for ages in all sorts of shops, and other buildings. But there are better ways.

But if you do go with rail and ties (wood, concrete, eteel, etc) under poured concrete, make sure it is tamped really well, there is a path for water to drain out from the ballast and either put a expansion joint or a saw cut parallel to the rail near the end of the ties so when the track settles, you have control of the cracking.

If the display is relatively static, then things are simpler, but if the track will be under regular traffic, please try and eliminate or minimize bolted joints in poured concrete. They will eventually pump and the concrete will crack.

Greg


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 Post subject: Re: rails in concrete
PostPosted: Wed Jul 18, 2007 12:37 am 

Joined: Thu Aug 26, 2004 2:50 pm
Posts: 2815
Location: Northern Illinois
Not being privy to the details of the building or its purpose (other than it’s not a shop) I really can’t comment on the wisdom of putting the track on the floor. After all, if these are to be permanent displays, having the full track structure visible under the equipment might be a plus, esthetically. I seem to recall several of the display “scenes” at the California State Railroad Museum are done like this. If the track is intended for rotating displays, however, the fixed length of the panels might be a bit limiting, and reconnecting the track to the rest of the world, or clearing the floor off the track, sounds like a hassle.

One thing we might be missing is that full size flangeways in the display floor may cause a problem with ADA compliance. They would definitely be a hazard to someone in a wheelchair. There is a flexible rubber flangeway filler made, Steamtown uses it, that is probably compliant, but be forwarned to look closely the details of installation. At Steamtown they cut the material to clear the joint bars, and the walking surface has collapsed at each joint as a result. I believe this material was developed for transit loading platforms in pavement, and most transit track is welded rail these days.

One other thing to check on. Be especially sure that the project architect / engineer understands what grade (elevation) the approach track will be at; steam locomotives can’t deal with the kinds of vertical curves they typically put in driveways, but they might not even realize this is an issue until after a lot of work is done, and needs to be redone. As I recall, there was some problem of this sort at the Henry Ford Museum; the building contractor for the roundhouse took his grades from the proposed rail HEAD, while the contractor for the turntable took his from the BASE of the rail. It cost someone a lot of money to get the situation straightened out.

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 Post subject: Re: rails in concrete
PostPosted: Wed Jul 18, 2007 1:18 pm 

Joined: Tue Aug 24, 2004 2:35 pm
Posts: 419
Location: NJ
Another thought came to me on this subject while discussing a railroad crossing upgrade I will be working on at my place of employment.

You can purchase pre-made concrete track panels for grade crossing replacements. These panels are placed on a graded surface and contain all the components neccessary to install the rail. They also provide a very long lasting crossing structure. This would be ideal for a static display or minor maintenance facility. I would be leary of using it for heavy duty restoration or overhaul work, but I am sure you could work with the manufacturer on getting the product you need.

Although expensive, it may be the most cost effective way to go instead of having an Architect / Engineering firm re-invent the wheel.

Look at the TraCast product here;

http://www.southeastrrsupply.com/RailroadCrossings.html

Or the Hanson Product;

http://www.hansonpipeandprecast.com/products_pgc.htm

CV the Civil E


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 Post subject: Thank you
PostPosted: Wed Jul 18, 2007 1:33 pm 

Many excellent ideas and comments in this thread.

Thank you for sharing your experiences and knowledge.


  
 
 Post subject: Re: rails in concrete
PostPosted: Wed Jul 18, 2007 5:12 pm 

Joined: Fri Dec 03, 2004 9:42 pm
Posts: 3013
cjvrr wrote:
Another thought came to me on this subject while discussing a railroad crossing upgrade I will be working on at my place of employment.

You can purchase pre-made concrete track panels for grade crossing replacements. These panels are placed on a graded surface and contain all the components neccessary to install the rail.


Yes, they are nice, and work quite well. I hadn't mentioned them previously since the installed cost is typically about $500 to $600 per track foot.

The other methods suggested can usually be done a lot more economically.


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 Post subject: Re: rails in concrete
PostPosted: Wed Jul 18, 2007 5:21 pm 

Joined: Fri Dec 03, 2004 9:42 pm
Posts: 3013
> One thing we might be missing is that full size flangeways in the
> display floor may cause a problem with ADA compliance. They
> would definitely be a hazard to someone in a wheelchair. There
> is a flexible rubber flangeway filler made, Steamtown uses it, that
> is probably compliant...

Yes, it's compliant, that's exactly what it's designed for. They're quite common on streetcar and mass transit installations. They eliminate the tripping hazard that would otherwise be there. The flangeway material will eventually wear out under heavy traffic and/or high speeds, but for a shop or other indoor installation it should work just fine. There are a couple different styles and types.


> but be forwarned to look closely the details of installation.

Always a good idea... :)

> At Steamtown they cut the material to clear the joint bars

Ideally, there shouldn't be any joint bars... They're the weakest point, and the most common source of problems. If you're putting track in concrete, or evern in asphalt, do yourself a favor and weld the rails!

Thermite field welds will work just fine, you don't need to haul in CWR, but if at all possible eliminate any joint bars in the paving and within 10 feet of the paved areas. It will create a much more uniform structure and you'll be glad you did in the long run.

A rail contractor can do the welds for you at a cost of about $500 each, depending on location and how many you need done, etc. It's a very good investment in the longevity of your structure.

BTW - If you choose to use the pre-fabricated concrete crossing method discussed above, you'll have no choice, they cannot accomodate joint bars.


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 Post subject: Re: rails in concrete
PostPosted: Wed Jul 18, 2007 5:26 pm 

Joined: Thu Aug 26, 2004 2:50 pm
Posts: 2815
Location: Northern Illinois
Exploring the Southeast Railroad Supply web site that CV the Civil E was nice enough to post a link to, I found the rubber flangeway fill I had seen at Steamtown, or at least something similar. It is at:

http://www.southeastrrsupply.com/RailroadRubberProducts.html

At the bottom right corner of the page. This is a hollow extruded tube that is expected to deflect under the wheel flange, then spring back up. I would suspect it would be useful to mitigate any ADA issues with flamgeways in a display hall floor.

The problem I noticed at Steamtown was that the contractor cut a notch in the bottom corner of the profile to clear the joint bars, With part of the tube gone, the top eventually sagged down into the void, reopening the depressions the rubber was meant to fill. So be forewarned.

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