We are reconstructing a stretch of highway with copies of old sets of plans from the original design. I am looking at a set that has a vertical profile for surfacing with an aerial view of the road surface. It has PC, PI and P.O.T. locations but, I was wondering if there is any abbreviation or something indicating a superelevation transition approaching a curve on a set of plans like this? I see P.O.S.T locations but, I don't know what that means. We have a survey crew taking shots as we go along but I would like to know in advance where we will have to change our underdrain from one side of the road to the other. Any help or input would be much appreciated.
First, P.O.S.T. around here means "Point On Straight Tangent" and can be almost nearly anything..up to and including a point on a hill that was convenient to set the instrument upon.
Super transitions lengths are a function of the design speed. If you can't dig up the specs that were applicable when and where the roadway was designed you can just look at the field shots for a spot where the crown disappears and the roadbed approaches 'flat' on the outside of the super.
I always thought P.O.S.T. meant Point on Semi-Tangent, but, that is essentially the same thing, ... carry on ..
There may be a superelevation diagram in the plans somewhere. It is usually found sandwiched between the profiles and plan sheets here in Colorado.
Mark Rhodes, post: 324110, member: 10105 wrote: We are reconstructing a stretch of highway with copies of old sets of plans from the original design. I am looking at a set that has a vertical profile for surfacing with an aerial view of the road surface. It has PC, PI and P.O.T. locations but, I was wondering if there is any abbreviation or something indicating a superelevation transition approaching a curve on a set of plans like this? I see P.O.S.T locations but, I don't know what that means. We have a survey crew taking shots as we go along but I would like to know in advance where we will have to change our underdrain from one side of the road to the other. Any help or input would be much appreciated.
Mark Rhodes, post: 324110, member: 10105 wrote: We are reconstructing a stretch of highway with copies of old sets of plans from the original design. I am looking at a set that has a vertical profile for surfacing with an aerial view of the road surface. It has PC, PI and P.O.T. locations but, I was wondering if there is any abbreviation or something indicating a superelevation transition approaching a curve on a set of plans like this? I see P.O.S.T locations but, I don't know what that means. We have a survey crew taking shots as we go along but I would like to know in advance where we will have to change our underdrain from one side of the road to the other. Any help or
Mark Rhodes, post: 324110, member: 10105 wrote: We are reconstructing a stretch of highway with copies of old sets of plans from the original design. I am looking at a set that has a vertical profile for surfacing with an aerial view of the road surface. It has PC, PI and P.O.T. locations but, I was wondering if there is any abbreviation or something indicating a superelevation transition approaching a curve on a set of plans like this? I see P.O.S.T locations but, I don't know what that means. We have a survey crew taking shots as we go along but I would like to know in advance where we will have to change our underdrain from one side of the road to the other. Any help or input would be much appreciated.
That could stand for, "point of super elevation transition"....normally you will see "E.N.C.(end normal crown)", or "E.S.E.(end super elevation)", or "E.F.S.E.(end full super elevation) or a variant of these(e.g.: B.F.S.E., B.N.C., R.C., B.S.E.). If you have the original cross-sections showing the cross-slopes of the paving, you can calculate the approximate, or exact, transition stations by using the transition rate from station to station.
vern, post: 324135, member: 3436 wrote: There may be a superelevation diagram in the plans somewhere. It is usually found sandwiched between the profiles and plan sheets here in Colorado.
There SHOULD be a superelevation diagram in the original drawings. Sometimes it is a graphical representation of the edge of pavement as referenced to the centerline.
Andy
I noticed that some of the P.O.S.T notes on the plans have a station number and some simply have a distance and say something like P.O.S.T. 375.303' and PI. BK. (1/2" Iron Pin). This may have nothing to do with what I'm looking for but I am curious. I don't see anything that says ENC, ESE, or anything like that. These plans are from the 80's but from what I understand these vertical and horizontal profiles are something that should be established in the design phase. I guess Ill just have to swallow my pride and ask the state inspector.
I think P.O.T. would mean point on tangent. Here in NY State super elevation diagrams are often shown under the profile. We use terms like:
Normal Crown
Run Off
Full Bank
If youre looking at a set of plans from the 80's you might just look for cross slopes drawn in the plan sheets with station call out. Youll have to calc them long handed
Do the drawings include spiral transitions in and out of the curves or are they all simple arcs?
Does "super elevation" simply mean "banking"?
I was watching a couple of my railroad buddies' videos one day several months ago and noticed some had banking in their curves so I asked about that.
All the replies mentioned "super elevations". At the scales most of us model in (HO mostly and some N), banking the curves introduces more track problems than it does provide coolness which is usually only noticeable through POV cameras mounted on board. Therefore, only the most serious modelers mess with it.
Ironically, that same day was a post over here regarding railroad layout and super elevations.
But this thread is regarding highway construction so now I would like some clarification if'n you'ns wouldn't mind.
E.
BigE, post: 324259, member: 435 wrote: Does "super elevation" simply mean "banking"?
I was watching a couple of my railroad buddies' videos one day several months ago and noticed some had banking in their curves so I asked about that.
All the replies mentioned "super elevations". At the scales most of us model in (HO mostly and some N), banking the curves introduces more track problems than it does provide coolness which is usually only noticeable through POV cameras mounted on board. Therefore, only the most serious modelers mess with it.Ironically, that same day was a post over here regarding railroad layout and super elevations.
But this thread is regarding highway construction so now I would like some clarification if'n you'ns wouldn't mind.
E.
Yes. and FYI when a railroad banks it is called cant
Roadhand, post: 324260, member: 61 wrote: Yes. and FYI when a railroad banks it is called cant
Interesting. I looked it up. It says "a lean; slope" but doesn't mention specific to railroads.
Good, I learned my new "something" for the day.
Thanks Roadie.
Roadhand, post: 324192, member: 61 wrote: If youre looking at a set of plans from the 80's you might just look for cross slopes drawn in the plan sheets with station call out. Youll have to calc them long handed
about 1/2 of the plans for texas highways are still that way... lol Or at least they are in the Beaumont district..
