Although it may well be that gravel is used here and there, the typical ballast and base for paving is crushed stone. The crushing produces sharp breaks and edges which encourage the stone to interlock and provide a stable base.
Dante
fwright All the handbooks I have seen on 20th Century track construction want a gravel bed in place before the ties are laid.
All the handbooks I have seen on 20th Century track construction want a gravel bed in place before the ties are laid.
Gravel is not ballast. It would seem to me (not having seen the process or owning a book) that this would be a much finer gravel such as is used in regular road building. The only tracks that I have watched being laid were in industrial sidings. The trackways were graded and built up as needed. Perhaps they used gravel, sometimes they do not. Then they stretch out the tracks, and then ballast them using all sorts of machinery.
Here is the BNSF mainline:
Here are the Red Trail Energy sidings:
And here is a project in action. They are replacing the ties and ballast on the track that the machine is running on.
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
With handlaid track, it's quite possible and practical to ballast before putting the rails down. When hand laying, I prepare the roadbed, glue the ties and put the ballast in while the glue for the ties is drying. I then sand the tops of the ties, which also takes out spots where the ballast is above tie top level. Then the rails are spiked in place. Dragging out the sequence approximates prototype track under construction stages if you have some surrounding scenery in place.
As for prototype practice, I see some misinformation here. All the handbooks I have seen on 20th Century track construction want a gravel bed in place before the ties are laid. If you are going to put the ties directly on the dirt, there is no real need for ballast. The gravel roadbed (ballast) provides drainage, and prevents the ties from "pumping" in the mud. Ballast is cleaned on a regular basis on main lines so that it maintains its draining properties - dust and dirt otherwise clogs it up. After the ties are laid, more ballast is added and tamped to lock the ties in place. Rails were the last pieces to be added before the days specialized track laying machinery.
just my observations
Fred W
Ballast on a real railroad has a structural function, namely helping to hold everything in place.
Ballast on your model railroad is decorative -- adding to the realistic appearance, but it shouldn't be adding structure to your road. And as others have pointed out, it's much easier to correct a trackwork problem if there is no ballast laid down.
While I'm sure you can find someone who's done it in the reverse order, I'd stick with the way most of us do it and lay the track first. And this also means you don't have to go back over everything to add ballast between the ties.
Connecticut Valley Railroad A Branch of the New York, New Haven, and Hartford
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Boris G BroadwayLion: Real Railroad Construction is not done this way. ... It might depend on local habits, climate etc, but in Sweden when they build yards and mainline they first go down to stable foundation, then fill up with different materials and then a layer of macadam that they will pack with a road roller. Then they lay the ties, the rail etc. /Boris
BroadwayLion: Real Railroad Construction is not done this way. ...
Real Railroad Construction is not done this way. ...
It might depend on local habits, climate etc, but in Sweden when they build yards and mainline they first go down to stable foundation, then fill up with different materials and then a layer of macadam that they will pack with a road roller. Then they lay the ties, the rail etc.
/Boris
Oops - I didn't finish:
After laying the rails on the flat rolled macadam ballast foundation they top off with more macadam and put the machines to work with alignment etc.
Although seen that in real life, I've started my small switching layout with cork on plywodd, I will add the ballast when I have the rail and wiring working.
I think that the advice you have received so far is excellent.
In my experience, it always makes sense to do things in the order that the real railroad does things. In the real world, track is laid first and ballast is added later.
It is also a lot easier and a whole lot more effective to ballast only after the track is laid and tested so that the ballast can be groomed and manicured to remove debris from the ties.
As Wayne asked, why would you even want to do this, that is, add ballast before laying track?
Rich
Alton Junction
onrfanatic Hello, I was wondering if anyone has ever tried to ballast and form the road bed on their layout first and then put the track down, and then added another layer in between the ties. I am pondering trying this on my new layout. If anyone has done this could you pass on any issues you had and any tricks to doing this. Or is it better to do the contours with ballast first around the cork and then add the track-like by doing one strip of HO cork with an N scals on top-ballast till it is even with the Nscale, then apply track and ballast again Cheers,
Hello,
I was wondering if anyone has ever tried to ballast and form the road bed on their layout first and then put the track down, and then added another layer in between the ties. I am pondering trying this on my new layout.
If anyone has done this could you pass on any issues you had and any tricks to doing this. Or is it better to do the contours with ballast first around the cork and then add the track-like by doing one strip of HO cork with an N scals on top-ballast till it is even with the Nscale, then apply track and ballast again
Cheers,
I'm curious as to why you'd even want to do this. Ballasting is one of the simpler modelling tasks if done after your track is in place and functioning properly. There's often a good reason for doing things in a particular order. While I find ballasting to be both relaxing and enjoyable (plus it offers great "bang for your buck"), many folks seem to struggle with it. It's perplexing that you'd want to do the operation twice, with what might be a long interval in between for track laying and fine tuning.
Of course, it's your railroad, so feel free to experiment. I have a premonition of a "Help!" post or two as a follow-up, though.
Wayne
BroadwayLion Real Railroad Construction is not done this way. ...
Thanks for the info, This is generally how I do it, i just read somewhere in a MR years back that some pre-ballasting was done first then the track added
Nathan
Cambridge, Ont
B & B Railways - "Connecting the North, one rail at a time"
Real Railroad Construction is not done this way. If new track is being laid, they lay the ties, then the rails, and then they ballast and perfect the alignment of the tracks. Working with existing track they can lift and move the tracks and re-pack the ballast all with one or two machines sitting right on top of the track they are working on. LIRR recently moved some of its tracks closer to the platforms to help eliminate the gaps. Did the work on weekends with the railroad running.
Unless you're talking about ballasting wooden crossties before hand-laying the rail, you might be able to get by with this, but for flextrack I think you will find it extremely difficult, if not impossible, to lay track on ballasted roadbed, because pieces of ballast under the crossties will make the track very unsteady and uneven.