evenfall
Banned-
Posts
788 -
Joined
-
Last visited
Everything posted by evenfall
-
Moose&Mickey, This has really been discussed at great length here on the forum, so rather than have another go at it, I would like to invite you to try looking at both the FAQ page Here: http://www.geocaching.com/mark/ And please read this entire thread which is a pinned topic started by the 2oldfarts: http://forums.Groundspeak.com/GC/index.php?showtopic=79709 Unfortunately there is no quick and dirty answer, but between those two you should come away with a well rounded set of answers for your questions and we all would be more than happy to help any other questions you have going forth from there... Thanks for your interest, I am sure we will have you off and hunting like a pro in no time! Rob
-
Well, I am not sure where we are with this, but one need only look at Jeremy's Bio to get where you need to go on Groundspeak... As excerpted from Jeremy's Bio: <snip> Jeremy is now the President and Co-founder of Groundspeak, Inc., the company that owns and operates Geocaching.com. Jeremy lives in the Seattle, Washington Area (aka The Emerald City) with his wife, and two beagles <snip> And returning us to the regularly scheduled program on this channel: SUN engineer in scheduled to be here at 8:30am tomorrow to replace disk. So we'll look for more info then! :-)
-
Art Man, I know they have a back up system for Disaster Recovery in Colorado, I am guessing since they just replaced a Hard drive over Thanksgiving and having this result so soon, perhaps they feel the problem may be beyond the scope of their Sys Admins and DBA's to handle. Sun Boxes are their own animal too. It could be that it is administrated by contractors now so as to control costs. IT is full of contractors these days as you know... Rob
-
Hi Dave, I am familiar with some of DeLorme's products. I have their Washington State Atlas and Gazetteer. It does not show the location of Survey marks in that offering. You know, I really do not consult it too often, but it covers topo mapping gaps I have in some areas... Sort of. It is not of intense detail. As to the Value of the map you are asking about, I cannot say, but I have a couple thoughts which I hope will give you some guidance. First, though you may already be aware, The game of benchmark hunting as we know it here on geocaching is played on the survey stations which are part of the NSRS, or National spatial Reference System, and administered by the US Government agency known as the National Geodetic Survey. Now as a rule, they do not publish any map, nor have they commissioned any other party to develop a map which would show where all of their Survey Markers are, or were located. So in a very big way your choice of map will not really get you where you want to go as far as the game of benchmark hunting will be concerned. However, there is more to the story. The USGS or U.S. Geological Survey set many Survey markers as well. Some, but no where near all were submitted to the NGS over the years for inclusion in the NSRS, so some of the USGS stations which are on the USGS Maps will be included as loggable finds for Geocaching. The only way to predetermine if the station you are looking for will be on a map, and playable for benchmark hunting as a game, is to look on the NGS Datasheet, available from the NGS website, or an older out of date copy from the Geocaching website. The Datasheet will tell you who monumented the station, and if it was monumented by the USGS, and included in the NGS NSRS, then it should for the most part be both on a USGS Map and Playable at Geocaching. Planning accordingly will be the only way you will really know if you have a good geocaching benchmark find or not. Going back to the DeLorme Question, is it a good value? It is hard to say, but my feeling is that it is hard to beat the source for mapping data. The USGS TOPO Maps on CD-ROM are the best value, and you can even work waypoints to and from your GPS with these computer based maps. then you can print the maps with your waypoints shown. If your waypoints are uploaded NGS Data, then you will have mapping for use with NGS-Geocaching based Marks. The point is , if you want maps like this, you will have to create them yourself and this is (basically) how. Followed next by topozone.com, a membership there would be of higher value although I have found everything I ever wanted on topozone for free. If I had to have something on paper, I would just go buy the actual Quads from a USGS Reseller, this way I can include the use of UTM grid for navigation. I know a lot of search and rescue types use UTM grids for searching, so the Quads are indispensable to them. For the GPS itself, I own Garmin's, and I would highly recommend owning the proprietary software for the respective brands and versions of the GPS units owned. My work has taken me out into the sticks on very remote logging roads, yet interestingly I have found that even those old dirt roads have shown up on my GPS Maps... As an aside, I was once in San Diego on business and was hungry for Mexican food. I had loaded the mapping for San Diego into my GPS prior to going. I looked up where I could find mexican food in my GPS and it showed me all the places in town starting with the nearest, including the Phone Number. So I phoned and got a table as the GPS showed me the way there. How cool was that? :-) It was a good meal too, by the way. It's your budget, but I think you get what you pay for. Rob
-
It would appear we are not out of the woods yet. NGS Database Status 12/06/04 5:37am - Disk containing master database failed. (master database controls everything) Disk mirroring kicked in. 9:30am - Databases put into 'read only' mode. (A couple running processes had to be killed.) Unix Sys administrator notified. 9:40am - Dump of master database failed. Sybase Support contacted. Still accessing the situation. 12:30pm - Unix Sys administrator waiting for phone call from SUN engineer to arrange disk replacement. He predicts it will not be replaced until tomorrow. 2:50pm - SUN engineer in scheduled to be here at 8:30am tomorrow to replace disk. Please continue monitoring http://www.ngs.noaa.gov/cgi-bin/db_status.prl For the latest updates. Rob
-
Mike, Thanks for checking in on that and keep asking the great questions! That is what the forum is all about! Rob
-
Very cool Kewaneh, :-) Rob
-
mrh, 446 ft is the elevation which was stamped on the disc, however the Topo seems to show EL=447 and you somehow got your consumer grade GPS to give you EL=446, which was a very good day for consumer grade GPS derived elevation... It could be a typo... I would tend to trust the leveled stamping myself, at least from the armchair. That would be USGS TT 12D 1938 In Indiana, I assume. DaveD may be able to research the original leveling for this station. So, N39 19.044 W087 33.225 Elevation 446 feet (your GPS derived elevation) shows a Datum shift of (NAVD 88 minus NGVD 29): -0.111 meter or 4.37 inches less, for those coordinates. So the 446 (NGVD 29 based on the original date of the leveling) is now a little more than 4 and 1/3rd inches lower than it was due to datum shift to NAVD 88 or 445.63 FT. That bench was placed and stamped during NGVD 29 Datum times due to the elevation stamping, which is a convention that stopped in the 60's, and they stamped the year on it besides. What ever the disc was stamped as, if accurate (since the topo does not seem to agree), is now 4.37 inches lower than the stamped elevation for latest, Datum shift adjusted, orthometric height. Just remember, that datum shift only applies to that set of coordinates. Geoid heights differ everywhere and the datum shift is geoid derived. As an aside, and FYI to all, this thread took me 6 minutes and 25 seconds to load due to the file sizes of the photos. Your milage may vary. I love the photos as much as anyone but can we try to limit the file sizes to around 100k each? If they cannot be resized, is it feasible to link to the photos somewhere off site so they will open in a new window? That is so much faster. When a thread gets this long, although there is no reason why a thread cannot be any length, or as long as is needed, all the photos just kill the load up... My hope is we can speed them up a bit somehow is all. Thanks! :-) Rob
-
Paul, I think that water tower is too "fare" from my Firehouse for me to "clam" too :-D Um, But who am I to argue with a four legged water tank found to be good in 1995?!? I wonder if a police report has been filed regarding the stolen tower legs... Ya think? Yeah! Most peculiar... I am calling CSI... Rob
-
John, Thanks, That makes sense. That was the sort of answer I was looking for. I know how it is, Here in the Puget Sound area, being a coastal area and pretty mountainous, the amount of Leveling and Triangulation is cumulatively enormous. Further, a lot of the Stations are gone. So in that frame of reference the PQ would make total sense, in that you can pare it down to a manageable size. I hate to keep falling back to work around scenarios, as I try to find a way to help, somehow. For now, in lieu of a better solution, would the county file in a pocket pc still seem doable? It is really just txt file so it would not be a memory problem. One could feasibly have all the data in there. I suppose it would not be as easy to be sure, but one could add way points to the GPS if need be. I only fly stations in by hand which were triangulation type into my GPS, and only if I arrive on scene and find them to be super obscure or buried. I never add Leveling (vertical stations) in as a waypoint as it is all scaled data, since my finding it and making a waypoint of that station on location will always improve the quality of the data. A GPS Fix on a Horizontally scaled station is an improvement any day. But again I digress, The PQ would narrow it down. On the other hand, the GPS is not necessary to find every benchmark either, so one could just use the data in the pocket PC to hunt. Will one of the popular programs allow people to select only the horizontal stations for waypoints? Meaning can the end user determine how they want to parse the data? That would narrow the field by half. There is no good reason to make a waypoint of a scaled station, so those would be seemingly easiest to hunt right from the narrative data. If one could choose accuracy orders. Another way would be to choose only Station disc types, landmarks of various types, or only hydrants, rivets or bolts. If you are seeking the very old, you could search for drill holes and as you know, cairns are always a very cool find. Nails and wooden object would almost always be a bad hunt. Third order horizontal would include all landmarks, but would rarely include stations with established azimuth marks. In fact in my area, Third order disc stations will more rarely have RM's when compared to First and Second order stations, however this may not be so in every locale. So if we could sort this way, all First and Second order Horizontal stations will always be ground stations, not landmarks, and may often have RM's and sometimes Azimuths. Bench Marks, meaning Vertical Stations of any order will rarely if ever have RM's and never an Azimuth Mark, but will often be on bridges, near water, and can be rivets or fire hydrants and other sorts of objects that Triangulation will never be. As a common naming convention they will most usually have a letter followed by three numbers and are often sequentially because leveling is most commonly done in lines of sequential numbers. This practice is used because optical leveling is path dependent and so the numbering kept track of the path. In some cases I have found RM's which have been leveled and so contain Vertical Data, they will have their own PID. Those are generally not always part of a level line. A and B order stations of horizontal or vertical data are GPS derived Data. Some may be old stations which have been updated, or newly monumented. First order stations were the most highly triangulated and are most often found in high places, or on view property as such. Another point you made once is that many PID's starting with A, AA-AI most commonly, but not in all cases, may have an affiliation with airports and are known as Primary or Secondary Airport Control Station PACS or SACS. One could parse those out if they didn't want to bother hunting on an airport. CORS and HARN stations will most often be realtime GPS stations. Maybe the most important way to parse the data for those who wanna play the game is to sort for those that are GOOD and POOR, while not fooling with the MARK NOT FOUND field... Going on and on, there are many ways to sort if you wanna, and I hope this helps to sort out what is what. Ok, so my idea is not a perfect fix, but it is a way to sort or narrow things down if you know what you want to hunt. It is just an effort to help. I would have to agree with you though, PQ's in the way you would have them function would help narrow the data into usable chunks. I just wonder if there isn't a private sector way of doing it, like a Radial search or Rectangular search of a given area. There is a website that gives latitude and longitude of any zip code, as in the post office's location as starting point, so that coordinate could be used to begin any given search. Another way to search is to download all the stations in a USGS Quad which is a method available on the NGS website, so theoretically you have a map and all the stations that should reside within it. I guess at this point I would ask, who wants to write the next cool program to do all this? It's all on the NGS Datasheet, you just have to parse out what you really want. :-) Thanks again John, that was the direction I was hoping for. Rob
-
Ok, I think I see where you are going but you nearly have it that easy now. Google the city you will be in to learn which county it is in, (unless you already know) and then download that county's data from the NGS website, They are set up for county by county data drops. Then covert it to the preferred format you like using BMGPX for your pocket PC then use EasyGPS for your GPS. It is still a 15 minute task and you have total control as well as all the candy. You don't even need the Geocaching website to accomplish this. It works 24/7. Like Caches are to geocaching, it is proprietary information from NGS so why not use the source? To have geocaching do it for us would be redundant and the info would be dated. To be sure, you could archive your entire state in the background while you were surfing in a different browser window so see, if you plan it out ahead it would not be a bother. Beyond that, you would have the latest data from NGS, the data that resides here in geocaching is almost 3-4 years old and would not show all the new stuff or the many recoveries that geocachers have accomplished already. This will help you know where the FTF action is as well. Maybe you still want the PQ's but the way I just outlined gets you the freshest meat at the market, and probably just as fast. More than that if you know how to read a datasheet! Rob
-
Flask, I am just trying to get my mind around the PQ concept for benchmarks. Perhaps you can help. In Caching, as I understand it, there are always new Caches being introduced in any given area, so as a paying member you will always be getting new PQ's to hunt. The PQ is the membership way of getting the new stuff. But the Benchmarks are all old, everything is public domain data, all laid out for free, even for the newest monumentation. There is nothing new in the way of Benchmarks coming to add to the cumulative total. Most are either Cooperative CORS stations or part of a HARN network and are basically owned and operated privately on a 24/7 realtime basis. Further, there are already programs and methods for re-parsing the NGS data so that it can be used by other programs, loaded in a GPSr or palm device, and you can do as much or as little of this as you like, all for yourself in house. So how would PQ's for benchmark hunting be of benefit? Just Curious. Rob
-
Graveyard Mom, Congrats on your find, That is very cool! You made a great discovery too in that the NGS datasheets are all you really need. Just a simple as printing out a few sheets of paper. Old school, but they never crash and always have the correct formatting. They come with the correct Datum and with the highest accuracy. There are many other clues as to what is going on with the survey mark you seek and others as well when you learn to read them, and this is something that is not available to you in any other format. Sometimes we find a few errors in the data, and this is easy enough to have corrected as it is a human system, yet they remain the best source for all the information and the cheapest way to go. In the simplest terms, you don't need a GPS to find a Benchmark, All you should really need is a simple paper datasheet. If it were not for the work done by the geodetic surveyors in the last 200 years, that these datasheets represent, a lot of things would be very different today. I just wanted to reiterate the lesson you learned today. I have made light of this in several prior posts. I will do it again because you have highlighted an excellent example. It kinda brings it home. When Geocaching.com created the game of benchmark hunting, they converted the NGS standard DDD.MM.SSSSS (degrees minutes seconds) format to DD.MM.MMM (degrees minutes decimal minutes) format, thinking that the convenience of using the default format the GPS is set to would be easiest. Well it is easier in not having to play with the GPS settings as long as you use the geocaching.com rendered data, but unfortunately the easy ends right there. When you move to the NGS datasheet, the bets are off. It is at that point your eyes will begin to play tricks. A couple problems arise from this. Let me explain. The NGS method of DDD.MM.SS format actually is age old and standard practice in surveying. An important thing to watch carefully is the .SS part of the format. that decimal point can and often does contain data 5-7 places to the right of the decimal point, and the further to the right it gets, the more accurate it is. So we would typically see something on a datasheet that could look like DDD.MM.SSSSSS . In the format change on the geocaching website, all data is format changed, and truncated to 3 places to the right of the last decimal. This means no matter how much data there originally was to the right of the decimal. The logic behind this is that this is all the accuracy the GPSr has in the first place, and in most cases is adequate to get us where we want to go. To the eyes in the field, the two formats, though they describe a similar location, the numbers look different and bring us doubt. For stations set close together, they can bring even more doubt. While we have all the options available, I recommend when hunting Benchmarks, to verify that the GPS is set to the NAD 83 Datum, which is the NGS owned Datum and used with these stations, (in fact these stations are in part and parcel the basis for that datum) Then affirm that your display format is set to DDD.MM.SSS format. This would be especially important if you intend to submit your recoveries to the NGS for inclusion in the Database, which the NGS encourages the geocachers to do. Conversely, when you want to geocache, the proper conventions for doing so would be to set your GPS to the WGS 84 Datum, and to the DDD.MM.MMM display format, which by the way, are most usually the default settings on most GPSr units. One more note of interest, you may notice that Many GPSr have the capability of using many many different datum, there is quite a list in there. Depending on where in the world you are, and the map you are using, that GPS likely can help you find your way. Good hunting Mom, :-) Rob
-
Weighing in, I would have to come down on Kewaneh's side with this, yet Blackdog has a good point on the marker type. Some marker types are better choices than others. We use the NGS survey Markers with NGS blessings, they are very hardy and sturdy survey markers. and to be sure, 680,996 in the geocaching database have not yet been found. The blessing to use the NGS markers is an important part of playing a game with these survey markers. By the numbers there is still plenty of challenge and adventure going forth with the geocaching database as it is. I can assure you as can many others, if you are looking for challenge, the NGS markers offer plenty, yet many are super easy no brainers. You never know. The USGS Markers not included in the NGS/geocaching database would be feasible to add as game pieces, but the USGS does not manage the survey they have in the field like the NGS does. Most are not in a computerized database which the public can use as such. Survey markers, when taken on the whole are pretty sensitive things. BLM PLSS Markers are used to describe real property in the field and many are much more fragile than an NGS or USGS "style" marker. Some in fact are not all that nailed down at all. They all are very important to legal property descriptions and are used to support legal matters in courts of law. Many surveyors, myself included are torn between the lucrative option of having updated information about older PLSS survey markers, especially in obscure areas, and at the same time don't really want the general public knowing too much about them for obvious reasons. What people don't know, they cannot affect adversely. Many other kinds of Survey Markers are privately owned and placed often temporarily at a cost to some party that needed them. The temporary nature of the Hub and Lath or Rebar and Cap makes them a poor choice in that they are of low stability, fragile, expensive (based on the work done to place them) and not meant with permission to become part of a game, which also makes them a poor choice. Worse yet, some temporary markers are placed in environmentally sensitive areas which are either ecologically fragile or filthy with hazmat waste. As a pedestrian citizen on any outing, I cannot always know what all survey markers are intended to signify, despite my training. So you see, a survey marker is not always just a survey marker, nor a good game piece in all cases. Some would be outright bad to use overall. The permissive nature and ready to use data of the NGS markers makes them the best bet yet. Rob
-
Just for the record for those who may wonder, there is no obligation on anyones part, but for those who may be interested in knowing as an example here, all 1000+ of seven's recoveries would be happily received by the NGS as a recovery, on the basis of a recently recovered survey marker alone. You could think of it like bumping up an old topic in the forum. It freshens up the last time the station was known to exist, and that adds value to the data in the database. This includes landmarks found or not found, any kind of station disc, bolt, rivet, drill hole etc... Found, not found or damaged, they like one report per year and are happy for the updates of any kind. Even if the description is adequate and the adjusted Coordinates are fine, (meaning it is triangulation and not leveling in most cases) every submission that anyone chooses to make with the care taken to do so accurately is a valuable submission to the data they use. They are also interested in the photos too if you would like to send them. Criteria is located in the Deb Brown pinned topic. I do not mean to say that anyone needs to do this, but they can choose to if they like. If there is not time in your life or you don't feel like doing it, that is as legitimate as any reason not to. It is strictly a volunteer effort. There need not be a personal criteria for submitting recovery to the NGS or not, but it always helps out if you choose to. Many people may already realize this, but for those who may not, now they do. Thanks, Rob
-
Geodetic Interactive Spatial Referencing Devices
evenfall replied to 2oldfarts (the rockhounders)'s topic in Benchmarking
Hi Rescue, As a Surveyor, I use the NGS database often and I also use the Stations in the field as well. More often, I use data that is based upon, or tied into this NGS database in many ways. Everything has a place and an elevation, and the records are kept. What you may not realize is that every city and town, county and state, Many government agencies including the armed services use the data in this database every day. They check to see how and where rivers flood, and if they can control this or maybe minimize it, and help the inertial navigation on an aircraft locate an airport as well as how a space shuttle flies home. They help ships navigate hazardous waters, and are the basis for how we measure the tides of the oceans and their effect upon our shores. Many are the frame of references for maps, and are also why when we flush our toilets or when rain falls on our streets, we no longer worry where the waste and water goes. They are at the basis for much of all engineered design. They helped us determine where to build hydro electric dams, are why the bridges line up from shore to shore and how insurance companies know whether you need flood insurance where you live, or not. These stations form the basis for something known as NSRS or the National Spatial Reference System. If you look in any phone book in America, seek out the Engineering Firms and Surveyors, the County and City Planners, GIS Managers and Departments of Transportation, the Railroads and the trucking firms who track freight with GPS, And finally ask any geocacher how important it is to them to use the mapping functions on their GPS, if the map matches the territory, and their way was never lost. Going back nearly 200 years now, if it were not for the work of the geodetic surveyors, there is a great deal we could not take for granted, as many things we know about our world and how we relate to it are thanks to them. :-) Does the NGS Notice? You bet! And they appreciate every time a Geocacher logs a recovery with their agency. Just because some are old and hard to find does not mean that the data that they represent was not and is not helpful, it all still very much is, in ways we might not know or realize. Currently, on average the NGS servers see about 200,000 NGS Datasheet downloads a month, to the general public, nationally from the NGS website. That adds up to 2,400,000 NGS datasheet downloads a year, so thank you for submitting your recoveries! Rob -
Congratulations Will! An excellent milestone! I hope we will still continue to enjoy your company here in the forums while you relax. You are in some pretty rare company whether they cache or not. As to why no Geocaches? Well, it could so easily be asked why have so many geocachers declined to benchmark hunt? I am sure the reasons are many and personal, but not all that important to the rest of us. People follow their inspirations and intentions, then they take action. Whether it is an exclusive thing or not, people remember us for what we achieve, not what we don't. It's really as simple as that. Again, Way to go Will! Rob
-
Goldfishy, This has really been discussed at great length here on the forum, so rather than have another go at it, I would like to invite you to try looking at both the FAQ page Here: http://www.geocaching.com/mark/ And please read this entire thread which is a pinned topic started by the 2oldfarts: http://forums.Groundspeak.com/GC/index.php?showtopic=79709 Unfortunately there is no quick and dirty answer, but between those two you should come away with a well rounded set of answers for your questions and we all would be more than happy to help any other questions you have going forth from there... Thanks for your interest, I am sure we will have you off and hunting like a pro in no time! Rob
-
Hi Ted, Yes that will work fine. The underscore is an optional unix file naming convention. I just use the underscore because it aids this particular human user in reading the filename better and faster when I am looking through my files. In other words, it wont matter to them, but it is a helpful aid for me and my eyes. Helps me find what I want with less squint and think. I can parse what "I" am looking for easier that way. After a few hours of dealing with data the eyes and mind tend to like the little things like that. Feel free to use either method as it applies to your way of dealing with your data, as long as it works for both you and Deb at NGS. Rob
-
Hi Patty, As a continuation of what Mike has said, in construction surveying, we will often seek a safe place to set a semi-permanent station so that throughout the course of the job, we have a couple places like this that will "see" the entire job site, and not get wiped out during the course of construction. After we have set these locations, our instrument, often a Total Station, which is basically a Theodolite with an EDM, (Electronic Distance Measurement) and sometimes a built in computer (some have external ones), is set over these stations and we turn the angles to and determine the distances to points that need to be built during the job. This is basically a form of open traverse from these points. We may locate property lines and rights of way, where a building is to be built, underground utilities and vaults, man holes, curbs, sidewalks, even where the lines will be painted on a road when it is all done, so proper lane widths match design etc. Any thing that needs to be located on the site plan is physically located this way. When the job is done the point is abandoned and it is likely a landscaper will be charged with removing the traces of ever having been there. On really large jobs that are hurry up jobs, sometimes more than one survey and engineering firm is working in ensemble, so part of the paint job and labeling may stand for who's control point that is. Sometimes, and Mike can confirm this, A private contractor will perform the work and may use their own surveyors. During and after, the respective State's DOT will perform a follow up survey to confirm things have been built to spec and verify as-built items, as well as perform any tweeks which signify the difference between what was planned and the actual build, because in the process of building, often changes are made on the fly. As for the bench mark station you are looking for, depending on the plan, it may be lost during construction. However you could contact your State's Geodetic Advisor and inform her, Marti Ikehara , of the situation and she may instruct the DOT inspector on the project of it's presence and to be mindful of it, if it can be preserved. For all we know they may know of it and are using it for vertical control on the project. It may say so on the metadata page of the plan. Happy Thanksgiving, Rob
-
fkrol, Have a look at this post Here. Hopefully it will bring you up to speed on why you are having trouble finding that marker in the database. Happy Thanksgiving, Rob
-
fkrol, Have a look at this post Here. Hopefully it will bring you up to speed on why you are having trouble finding that marker in the database. Happy Thanksgiving, Rob
-
n0wae, Heres a link to a to a thread I posted in while back that was written to address stations like the one you found. You can have a look at it Here. In addition to all the other great info on this thread, I hope it helps! Happy Thanksgiving, Rob
-
Hi Tayjam The rivet will likely appear like the one in the photo submitted by holograph. (thanks Holograph, :-) ) The PID is a term coined by the National Geodetic Survey. They are the agency which owns and supplies the data for the benchmarks... PID stands for Point ID. ID as in identification. The one you linked to leads to a page titled Details for Benchmark: NK0390. The Number, NK0390 is the PID. The rivet as I suspected is in an old steel bridge and was set by the railroad that built the bridge. It will look like the other rivets in the bridge only set into the concrete abutment, so as to mark a place of known elevation. Since this is on a railroad bridge I would like to caution you. Railroad property is an inherently dangerous place. To add, I do not know if this bridge is still in active use or not, but I can tell you that railroads are severely not a good place to trespass post 9/11. They do not take kindly, their railroad security officers have federal authority and they can arrest and deal with you harshly. You are a terrorist until determined not to be. Permission must be obtained to access their properties and all railroad personnel are trained to be the eyes of security for the officers. The best plan to have when dealing with the railroads is to just hunt the other ones. Rob