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Use Civil 3D to set up rail alignment and calculate rail cant, including for tangent sections.
Transcript
00:00
In this video, we will set up our alignment and calculate rail cant.
00:08
We'll also look at some of the new features and tools where we can add cant to specific locations on our alignment,
00:16
including tangent sections.
00:18
To begin, we need to set up our alignment prior to calculating the cant.
00:22
So, let's select the eastbound track and go to Alignment Properties.
00:26
We need to verify the alignment is a rail alignment.
00:30
In this case it is, and we can change that here if needed.
00:33
Under the design criteria, we can specify our design criteria, and it tells us we need to set our alignment speed first.
00:41
So, let's set that up now.
00:43
Based on this alignment, we need to set up a few design speed areas.
00:47
We have our first limit, and then we can set additional limits based on the station location and the speed.
00:55
When we use the selection tool, we can pick those station limits in plan view.
00:59
We can adjust the speed as needed, and we'll do this for the rest of our alignment.
01:05
Once we select OK, our label styles will show the speed locations.
01:10
We can review those if needed.
01:12
We can also move these labels if we have any conflicts using the grips.
01:16
And then we'll add the design speed locations for the westbound track as well with the same process.
01:22
And if we have overlapping labels, we can hold control, then select the label, then right-click to flip the label.
01:31
At this location, we can actually see that the eastbound limit is not in the right location, it's in the spiral.
01:36
So, we can easily edit this value and update it once we apply the new limit.
01:41
So once that's set, we'll do some last clean-up, and then we should be set for our design speeds.
01:49
Looking at a few items in alignment properties, we can look at the track width.
01:53
The default value gives the center-to-center spacing, but we can change that to the gauge width,
01:58
or we can adjust it, depending on our rail size. In this case, we're using 50-kilogram rail.
02:04
For now, we'll leave the default values.
02:07
Since we have our speed set, we can determine the criteria we're using.
02:10
Again, we'll stay with the default metric criteria.
02:14
We can review some of the other tabs.
02:15
We don't really need to change anything.
02:17
We'll stay with the defaults.
02:19
And if we're using freight rail, we could set this to cord definition under the Station Control tab.
02:24
The default setting is for ARC definition, so we'll leave this as it is for now.
02:28
Everything else looks okay.
02:31
So, under the Rail tab, we'll choose Calculate.
02:34
Then we'll pick our alignment, and we'll choose to Calculate now.
02:37
The track width is based on the value that we set in our alignment properties,
02:40
and we'll determine the method of super elevation, whether it's the low rail, high rail, or center.
02:47
We'll stay with the low rail setting.
02:49
The criteria is based on our design speed, but we could adjust those values here as well.
02:53
Once we select finish, we will see the calculated values and the station locations with the applied cant
02:58
and we can see the other values in the table.
03:01
If needed, we can adjust any of those values in this table.
03:06
In this example, we've already calculated the applied cant and the spiral links in a spreadsheet, and I want to match those values.
03:14
So, I can compare the values and adjust the table by picking the cells and revising them.
03:19
When I select the cell, the corresponding alignment element will highlight in Plan view.
03:25
So, once I'm happy with those calculations, I can close the window.
03:30
We'll do the same thing on the westbound side.
03:33
Now if we need to go back and make any revisions to the cant, we can run the same command, the Calculate command.
03:38
This time, we'll see a different window come up.
03:40
This will display the alignment geometry and the criteria.
03:43
In the Cant wizard, I can actually specify the entire alignment or specific curves that need to be recalculated.
03:52
Then, we'll see the same window and the table to indicate the values.
03:59
Then we can view the Cant diagram by selecting Create Cant View,
04:04
and I can pick the alignment, then choose the location of where I want my diagram.
04:10
And this will show us the stations, the transition lengths, the low and the high rail, as well as the equilibrium cant.
04:17
This is valuable information, particularly when we're creating track charts or plan sheets.
04:24
So now, let's look at creating custom cant in tangent sections.
04:29
We have a section of tangent where we want to add cant.
04:32
It could be for a conflict or a platform, really any reason.
04:35
And we can zoom into that area, and we'll choose calculate cant.
04:40
And we'll specify our alignment, in this case, the eastbound.
04:43
And in the cant window, we have the option to choose Create User Defined Curve.
04:49
And when we select this, it will ask for a segment of our alignment.
04:52
So, we will pick this tangent section.
04:55
Zooming out a little bit, we can see that this has highlighted our tangent.
04:59
And as a guide, let's add a line that will show us where we want to add our cant.
05:05
For this, we'll just place a polyline near our track, and then we'll have a transition on either side of this section.
05:11
We'll add a radius to provide a basis for the calculation.
05:15
And so here, we'll add a fairly large value.
05:18
And we can determine the direction of the curve.
05:21
This is going to dictate the rotation of our track, so we'll stay with a left curve, and this will rotate toward our westbound track.
05:30
And we could also revise the speed for this transition as well.
05:34
And we'll keep it as it currently stands.
05:36
Now, once we're set, we'll choose Cant Wizard and the calculation window comes up.
05:41
We only want to redefine this new curve.
05:44
We don't need to change anything else.
05:46
So, we'll select OK, and we'll stay with most of the defaults.
05:49
Again, we're using the metric calculation.
05:52
Once we select Finish, we can see our cant table and we have a number of alerts.
05:57
And this is telling us that we have overlap between areas that we need to correct.
06:03
So, we can define the stations for the transition locations.
06:07
And we'll do that now.
06:08
So, we'll begin by identifying the transition location.
06:11
Next, we'll set the full cant station.
06:15
Then we'll define the end full cant location.
06:19
And again, these are loosely based on our polyline.
06:23
And then finally, the begin level track station.
06:26
And this gives us about 60 meters on each side for transition.
06:31
And we want to redefine those cant values, and we'll set this to 50mm.
06:36
So, as we select each location, we can see a marker in plan view to give us an idea of where these transition locations are.
06:45
This is a really great sanity check.
06:47
The rest of our alignment will remain as we set earlier and then we'll go back to our cant view diagram,
06:54
and we can see the new user defined information: where the transition locations are, as well as the full cant values.
07:03
The final thing we'll look at is how we can use the cant view chart to edit the cant values graphically.
07:10
So, when I select the table, several different grips will appear.
07:14
Here, I'll edit the applied cant value, and I can also input the exact amount that I want, and the chart will update.
07:21
In many cases, we may have very complex cant requirements where we need to change the transition length and rate.
07:28
We can select the chart again using the grips and I can manually adjust the transition location.
07:34
When I hover over the grip, I can add a station to create an inflection point in the transition rate.
07:42
This is extremely helpful when we need to include rate variations or when we have complex geometric situations,
07:49
particularly when it comes to applied can't.
07:52
And I can add as many of these as needed.
07:53
And the tabular editor will also show the station values, and we can edit these as needed.
08:01
So, some tools that really give us complete control over how we want to identify and define the cant for our rail.
00:00
In this video, we will set up our alignment and calculate rail cant.
00:08
We'll also look at some of the new features and tools where we can add cant to specific locations on our alignment,
00:16
including tangent sections.
00:18
To begin, we need to set up our alignment prior to calculating the cant.
00:22
So, let's select the eastbound track and go to Alignment Properties.
00:26
We need to verify the alignment is a rail alignment.
00:30
In this case it is, and we can change that here if needed.
00:33
Under the design criteria, we can specify our design criteria, and it tells us we need to set our alignment speed first.
00:41
So, let's set that up now.
00:43
Based on this alignment, we need to set up a few design speed areas.
00:47
We have our first limit, and then we can set additional limits based on the station location and the speed.
00:55
When we use the selection tool, we can pick those station limits in plan view.
00:59
We can adjust the speed as needed, and we'll do this for the rest of our alignment.
01:05
Once we select OK, our label styles will show the speed locations.
01:10
We can review those if needed.
01:12
We can also move these labels if we have any conflicts using the grips.
01:16
And then we'll add the design speed locations for the westbound track as well with the same process.
01:22
And if we have overlapping labels, we can hold control, then select the label, then right-click to flip the label.
01:31
At this location, we can actually see that the eastbound limit is not in the right location, it's in the spiral.
01:36
So, we can easily edit this value and update it once we apply the new limit.
01:41
So once that's set, we'll do some last clean-up, and then we should be set for our design speeds.
01:49
Looking at a few items in alignment properties, we can look at the track width.
01:53
The default value gives the center-to-center spacing, but we can change that to the gauge width,
01:58
or we can adjust it, depending on our rail size. In this case, we're using 50-kilogram rail.
02:04
For now, we'll leave the default values.
02:07
Since we have our speed set, we can determine the criteria we're using.
02:10
Again, we'll stay with the default metric criteria.
02:14
We can review some of the other tabs.
02:15
We don't really need to change anything.
02:17
We'll stay with the defaults.
02:19
And if we're using freight rail, we could set this to cord definition under the Station Control tab.
02:24
The default setting is for ARC definition, so we'll leave this as it is for now.
02:28
Everything else looks okay.
02:31
So, under the Rail tab, we'll choose Calculate.
02:34
Then we'll pick our alignment, and we'll choose to Calculate now.
02:37
The track width is based on the value that we set in our alignment properties,
02:40
and we'll determine the method of super elevation, whether it's the low rail, high rail, or center.
02:47
We'll stay with the low rail setting.
02:49
The criteria is based on our design speed, but we could adjust those values here as well.
02:53
Once we select finish, we will see the calculated values and the station locations with the applied cant
02:58
and we can see the other values in the table.
03:01
If needed, we can adjust any of those values in this table.
03:06
In this example, we've already calculated the applied cant and the spiral links in a spreadsheet, and I want to match those values.
03:14
So, I can compare the values and adjust the table by picking the cells and revising them.
03:19
When I select the cell, the corresponding alignment element will highlight in Plan view.
03:25
So, once I'm happy with those calculations, I can close the window.
03:30
We'll do the same thing on the westbound side.
03:33
Now if we need to go back and make any revisions to the cant, we can run the same command, the Calculate command.
03:38
This time, we'll see a different window come up.
03:40
This will display the alignment geometry and the criteria.
03:43
In the Cant wizard, I can actually specify the entire alignment or specific curves that need to be recalculated.
03:52
Then, we'll see the same window and the table to indicate the values.
03:59
Then we can view the Cant diagram by selecting Create Cant View,
04:04
and I can pick the alignment, then choose the location of where I want my diagram.
04:10
And this will show us the stations, the transition lengths, the low and the high rail, as well as the equilibrium cant.
04:17
This is valuable information, particularly when we're creating track charts or plan sheets.
04:24
So now, let's look at creating custom cant in tangent sections.
04:29
We have a section of tangent where we want to add cant.
04:32
It could be for a conflict or a platform, really any reason.
04:35
And we can zoom into that area, and we'll choose calculate cant.
04:40
And we'll specify our alignment, in this case, the eastbound.
04:43
And in the cant window, we have the option to choose Create User Defined Curve.
04:49
And when we select this, it will ask for a segment of our alignment.
04:52
So, we will pick this tangent section.
04:55
Zooming out a little bit, we can see that this has highlighted our tangent.
04:59
And as a guide, let's add a line that will show us where we want to add our cant.
05:05
For this, we'll just place a polyline near our track, and then we'll have a transition on either side of this section.
05:11
We'll add a radius to provide a basis for the calculation.
05:15
And so here, we'll add a fairly large value.
05:18
And we can determine the direction of the curve.
05:21
This is going to dictate the rotation of our track, so we'll stay with a left curve, and this will rotate toward our westbound track.
05:30
And we could also revise the speed for this transition as well.
05:34
And we'll keep it as it currently stands.
05:36
Now, once we're set, we'll choose Cant Wizard and the calculation window comes up.
05:41
We only want to redefine this new curve.
05:44
We don't need to change anything else.
05:46
So, we'll select OK, and we'll stay with most of the defaults.
05:49
Again, we're using the metric calculation.
05:52
Once we select Finish, we can see our cant table and we have a number of alerts.
05:57
And this is telling us that we have overlap between areas that we need to correct.
06:03
So, we can define the stations for the transition locations.
06:07
And we'll do that now.
06:08
So, we'll begin by identifying the transition location.
06:11
Next, we'll set the full cant station.
06:15
Then we'll define the end full cant location.
06:19
And again, these are loosely based on our polyline.
06:23
And then finally, the begin level track station.
06:26
And this gives us about 60 meters on each side for transition.
06:31
And we want to redefine those cant values, and we'll set this to 50mm.
06:36
So, as we select each location, we can see a marker in plan view to give us an idea of where these transition locations are.
06:45
This is a really great sanity check.
06:47
The rest of our alignment will remain as we set earlier and then we'll go back to our cant view diagram,
06:54
and we can see the new user defined information: where the transition locations are, as well as the full cant values.
07:03
The final thing we'll look at is how we can use the cant view chart to edit the cant values graphically.
07:10
So, when I select the table, several different grips will appear.
07:14
Here, I'll edit the applied cant value, and I can also input the exact amount that I want, and the chart will update.
07:21
In many cases, we may have very complex cant requirements where we need to change the transition length and rate.
07:28
We can select the chart again using the grips and I can manually adjust the transition location.
07:34
When I hover over the grip, I can add a station to create an inflection point in the transition rate.
07:42
This is extremely helpful when we need to include rate variations or when we have complex geometric situations,
07:49
particularly when it comes to applied can't.
07:52
And I can add as many of these as needed.
07:53
And the tabular editor will also show the station values, and we can edit these as needed.
08:01
So, some tools that really give us complete control over how we want to identify and define the cant for our rail.