Horizontal/Subsurface Infrastructure & Transportation

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Coordinates for Layout

  • 1.  Coordinates for Layout

    Posted 02-16-2018 02:27 PM
    I have to ask if other folks are seeing a trend with horizontal layout sheets.

    I was trained to include ​control points along with bearings and distances. We used to also dimension the hell out of drawings. The Rule of Thumb I was given was to imagine having to be in the field to lay out the project and to provide information that an inspector could use to verify dimensions.

    I'm seeing that go the way of the dodo.

    Seems like engineers are providing points with coordinates now. That and they're providing CAD files, too.

    With GPS units being somewhat ubiquitous on construction sites, I also see contractors not hiring honest to goodness surveyors.

    I feel like I'm seeing more busts with layout than I ever did in the past. Anyone else seeing the same thing?

    ------------------------------
    Shelly Hattan P.E., M.ASCE
    Tarrant Regional Water District
    Fort Worth TX
    ------------------------------


  • 2.  RE: Coordinates for Layout

    Posted 02-17-2018 11:57 AM
    Edited by Tirza Austin 02-17-2018 11:56 AM
    ​The purpose of a set of plans is to provide the information necessary for a contractor to construct the intended facility. It is not likely that a designer woke up one morning with a set of coordinates in mind that expressed his/her intent. It is more likely they started with ideas like, the storm line should parallel the street or the sanitary should be more than 7 feet from the sanitary line. These intended results should be expressed on the plan sheet along with the dimensions and reference objects that a construction person could actually visualize and use to build the facility.

    The current and emerging practice of providing CAD files for office use and coordinate dumps for the field is very quick way to screw up a project. It provides very little help to visualize the designer's intent.

    Andrew L. Sikes PE RPLS
    Houston, TX

    ------------------------------
    Andrew Sikes P.E., P.L.S., M.ASCE
    Pres
    Andrew Lonnie Sikes Inc
    Houston TX
    ------------------------------



  • 3.  RE: Coordinates for Layout

    Posted 02-18-2018 11:00 AM
    In my experience there is a trend towards minimising the number of drawings produced in many disciplines in a misguided attempt to reduce engineering budgets. This not only results in the construction problems you refer to but commercial issues as well. It is not possible to fully convey the scope of work in an un-annotated CAD file. The money saved (if any) in the design office is written off many times over in paying for rework and contract variations once a project reaches the construction phase.
    Cheers
    Brian

    ------------------------------
    Brian Marshall P.E., CPEng, M.ASCE
    Civil engineer
    Bardon
    ------------------------------



  • 4.  RE: Coordinates for Layout

    Posted 02-19-2018 06:18 PM

    ​Agree that "minimising the number of drawings produced in many disciplines in a misguided attempt to reduce engineering budgets." 

    So, how do we convince clients, management, funding agencies, etc. of that simple concept?



    ------------------------------
    Denis O'Malley P.E., M.ASCE
    Principal
    Denis M. O'Malley, PE, PMP
    Concord CA
    ------------------------------



  • 5.  RE: Coordinates for Layout

    Posted 02-27-2018 10:10 AM
    To minimize dimensioning a drawing as a cost saving measure doesn't make sense. Having CAD files sent to the contractor is really a matter of convenience. It makes the drawings readily available and easy for the contractor to print as many as they want when they want. 

    With CAD available, it should even be easier to add as much detail as possible..

    ------------------------------
    Bryan Kalundu Aff.M.ASCE
    Assistant Civil Engineer
    Batoka Gorge Power Coorperation Ltd
    Lusaka
    ------------------------------



  • 6.  RE: Coordinates for Layout

    Posted 02-18-2018 11:01 AM
    I've noticed two different attitudes about providing CAD files - one is fear that providing them gives contractors a possible route for evidence in filing claims from potentially fudged designs, the other is that ever more technologically savvy contractors can make good use of them in cutting costs, therefore bids.  Electronically supplied spatial information with GPS data can be easily and accurately converted to station and offset.

    "That's not data, that's a piece of paper"

    ------------------------------
    Stephen Hemphill, P.E.
    Rio Rancho NM
    ------------------------------



  • 7.  RE: Coordinates for Layout

    Posted 02-19-2018 06:17 PM
    ​Just a few basic thoughts ... ASCE 38-02 is definitely the source for standard guidelines regarding Subsurface Utility Engineering (SUE). The FHWA, FAA and other entities have adopted similar language regarding utility information.

    SUE services are primarily intended to serve the engineering or "design" community; not contractors. Unfortunately, many project owners and some design firms want to pass off the responsibility for "the collection and depiction of subsurface utility information" to surveyors or worse yet, contractors; primarily in the interest of saving money.

    The bottom line here is that any project owner or design firm who does not recommend or accept as an element of their scopes of work, employment of the appropriate quality level(s) of SUE services, is leaving themselves wide open for the risk (liability) associated with utility related construction delays, engineering re-designs, utility relocations, etc.

    SUE has been around too long now for folks to be pleading ignorance. The good old days of disclaiming any responsibility for utility information by adding a "not my responsibility" stamp to engineering design or survey work products is over. RIP.

    ------------------------------
    Michael Rice Aff.M.ASCE
    V.P. - SUE Operations
    So-Deep, Inc. / SAM, LLC
    Austin TX
    ------------------------------



  • 8.  RE: Coordinates for Layout

    Posted 02-18-2018 10:59 AM
    Here in Nepal that is not a problem! Every owner must hire a registered architect/ engineer to get the house designed and plans prepared with seismic forces taken into account.
    Then the plans must include a site plan which shows the situation of the building in side the plot, and a location plan which clearly defines the exact location of the plot with reference to adjacent road, electric pole, drains if any and four side neighbors or structures.
    This makes the laying out of the proposed building easy.

    ------------------------------
    Peter Singh M.ASCE
    Managing Director
    Kingdom Designers
    Birganj
    ------------------------------



  • 9.  RE: Coordinates for Layout

    Posted 02-19-2018 05:55 PM

    We have been asking for the CADD drawings for over 20 years. We would rather have the electronic file than the paper drawing.

    Imagine how much more information is available electronically as opposed to the often cited "contractual" paper document. Many of the contracts we see today mention digital data instead of paper documents.

    How do you think the Designer updates his information?



    ------------------------------
    Michael Falk P.E., P.L.S., F.ASCE
    President/CEO
    Falk P.L.I.
    Portage IN
    ------------------------------



  • 10.  RE: Coordinates for Layout

    Posted 02-19-2018 05:57 PM
    There can be a problem converting a GPS survey to an existing system if the drawings you receive either give you the equations you need to convert the GPS information to the system you are using or furnish information that you can use to calculate the equations necessary to convert the information yourself.  I just recently had to convert a GPS survey to a plant grid system where plant north is not true north.  I was able to convert the GPS survey to plant survey using points the furnished GPS coordinates along a line that was parallel to plant north.  

    When you are requesting a GPS Survey, make sure you request the information you need, including point that you can use to coordinate the GPS survey with the system you are using.  Also, you should request the surveyor furnish survey drawings drawn to your coordinate system.

    ------------------------------
    Kenneth Clark P.E., M.ASCE
    Civil Engineer
    Oklahoma City OK
    ------------------------------



  • 11.  RE: Coordinates for Layout

    Posted 02-19-2018 06:00 PM
    ​Shelly's original point is right on.  The trend to using coordinates is built on the assumption of complete accuracy of survey and design dimensions.  The point of design intent and the need to fit the design to actual field conditions is lost when reliance is based solely on CAD coordinates for field layout.  Surveyors attempt to obtain coordinates for key features, but no survey is so complete that it includes every nook, chink and detail of a site that might affect the field layout.  Arguably, use of LiDAR can reduce this by collection millions of points, but this often just serves to cloud the issue. Too much data can make the resolution of surface details amongst the clutter of vegetation, passing birds, parked cars, and other superfluous items that appear in a laser scan, difficult and can introduce uncertainty into the interpretation of conditions.    Coordinates generated through computer applications such as CAD also typically compute to significant figures beyond what is reasonable based on the source data.  The use of designer's coordinates alone to justify change order's puts and unreasonable burden of accuracy and precision on the engineer, especially, where the designer is relying on a survey by others, and circumvents the contractor's responsibility to verify conditions during the construction process.  There may also be a false sense of economy on the part of engineers. in the over-reliance on technology, thinking that they do not have time to call out critical dimensions and define essential criteria for field checking where conditions are not as well defined as the CAD coordinates may imply. Regardless, the contractor's role in defining actual conditions is critical to proper construction.  In an ideal world, construction would be an extension of design as it was in the day of the master builder instead of the adversarial process it has become.

    ------------------------------
    Michael Byle P.E., D.GE, F.ASCE
    Tetra Tech Inc.,
    Langhorne PA
    ------------------------------



  • 12.  RE: Coordinates for Layout

    Posted 02-19-2018 05:56 PM
    In Canadian infrastructure, contract drawings should show design intent, but cannot be expected to show all details, including layout details. This differs from other jurisdictions I've seen, where it is expected that all details necessary for construction and layout are to be included in the contract drawings. 
    The trend we see more and more is that to supplement the contract drawings, Contractors are provided an electronic model, usually in Revit/Navisworks for buildings and .XML / 3D CAD for earthworks, sewers and other Civil works. From this model, the construction surveyors can obtain all the coordinate information necessary for building and civil layout, and can extract information for machine-guided earthworks equipment. 
    The driving force behind the trend is that this method has resulted in better coordination between the design and field units of the construction project, since the model provides one common language and one common frame of reference, and also makes survey QA/QC easier.

    Cheers.

    ------------------------------
    Sergio Fernandez P.Eng, M.ASCE
    Senior Transportation Engineer
    Calgary AB
    ------------------------------



  • 13.  RE: Coordinates for Layout

    Posted 02-20-2018 09:51 AM
    Edited by Tirza Austin 02-20-2018 09:50 AM
    In the Interest of profession providing soft editable files to the client is not good (specially in developing countries) because client (specially government client) doesn't make payments as per contract in time or as agreed in contract on the one hand and on the other hand once they get editable CAD files and coordinates they do not need you anymore because they copy it and make next phases of the project and use it for many things just altering it a little bit and may tell you that your work was not good or we have a new work (whereas in reality they just use your CAD files lets say alignment in case of road or rail project and do a little change using your CAD file and tell public its a new work) Also on Government client side they are not experts that is why we are appointed as engineering consultants but once they get editable soft copies and they know our methodology from our submissions they assume that now they can copy and assume themselves as experts so they not only use it for the same project but for other projects. So i am totally against giving soft editable files to the government client unless and until your services are not only up to the stage of concepts, design, estimation and project report but also for the project management and supervision.


    ------------------------------
    Rohit Gupta R.A., A.M.ASCE
    Rohit Associates Cities & Rails Private Limited
    Mumbai MH
    ------------------------------



  • 14.  RE: Coordinates for Layout

    Posted 02-21-2018 04:38 PM

    I really don't understand how we got here, but the level of detail shown on issued for construction drawings has become less over time.

    Meanwhile there has been tremendous advancements in technology for subsurface investigations as well as creation of drawings, such that we have better tools available to both identify and depict existing conditions and to define new items to be installed with 3D accuracy.

    However, there has been more of a trend to complete documents faster and at lower cost, thereby negating the generation of more information on construction documents to help avoid conflicts.

    When I was a design engineer, I was taught to provide a construction baseline and coordinates to facilitate constructability.  This has become a rarity today, I believe because project owners do not want to pay for that level of detail.

    This change is our industry which has essentially caused the commoditization of engineering services and reduced the engineering profession to that of Technician status, where the only metric that matters to project owners is low price, often veiled as best value or price leader.

    The result is less information available to contractors for construction, which translates to increased risk and ultimately higher costs for construction.

    This trend needs to be reversed, it simply makes more sense to apply more effort during design to produce more complete and accurate documents for construction, lowering the risks, and improving costs...ultimately having greater success in execution of projects, while providing better protection to existing underground assets.

     

    Gerald Donnelly, P.E., P.Eng, MASCE

    Executive Vice President

    STV Energy Services, Inc.

    205 West Welsh Drive,

    Douglassville, PA 19518

     

    Direct: (610) 385-8448

    Mobile: (610) 914-8174

    Email: gerald.donnelly@...

    http://www.stvinc.com/energy.aspx

     




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  • 15.  RE: Coordinates for Layout

    Posted 02-20-2018 09:52 AM
    I vote for not giving up on a paper set of drawing, no matter where they originated. Yes, I am "old school" and I realize CADD is a great tool. Give me a hard copy, please.

    ------------------------------
    John Hart EIT, M.ASCE
    Retired
    Columbia SC
    ------------------------------



  • 16.  RE: Coordinates for Layout

    Posted 02-20-2018 11:43 AM
    Edited by Tirza Austin 02-20-2018 11:42 AM

    Interesting discussion.  I believe that the challenge of providing AutoCAD files to contractors for layout is an understanding of the limitations of accuracy in the files and conveying those limitations.  With paper drawings the surveyor relies on written dimensions and cannot scale locations.  With AutoCAD files you by default scale locations. That is fine if the consultant knows from the beginning everything will be scaled and is given the time to accurately locate all the points. I dealt with a job where the locations of all the piles were changed 24 hours prior to the drawings needing to be issued.  All the large scale details were changed, and the dimensions were taken off the plans. The contractor was required to sign a sheet indicating that the drawing should not be scaled and used by only certain people. The contractor gave the release sheet to the surveyor to sign and all the files were located by scaling.  A big mess. 

    When releasing computer files remember locations used for layout will be done by scale. (It is faster)



    ------------------------------
    David Thompson P.E., M.ASCE
    Principal
    KTA Structural Engineers Ltd.
    Calgary AB
    ------------------------------



  • 17.  RE: Coordinates for Layout

    Posted 02-20-2018 01:38 PM

    While working for a general contractor on fairly complex construction projects, we always had competent surveyors perform basic layout and, that layout was then handed-off to various trades to complete the construction work.  The designer's CAD files provided a resource that raised the construction phase to a new level of technology not before available.  Our surveyors programmed design coordinates and elevations into their EDM equipment making for a smoother and more accurate method of transferring information from design to construction layout in the field.

    Sometimes our surveyors found busts in the design data comparing building coordinates to dimensional information on architectural, structural, mechanical, etc. drawings.  That led to producing RFI clarifications early on in the project eliminating costly changes later on.  Also, having the CAD files available for our use made exchange of information between GC, engineer, architect, owner and subcontractors easier, complete and accurate.

    If the designer has fear that providing CAD information might give evidence for claims, that's a moot point since that information would become available through discovery at some point in litigation.  If the designer is hiding something or knows of inadequate design details then there are other problems the designer needs to address other than worrying about providing electronic drawings.

    As far as budgetary concerns with design expense, I fully believe that the design should be provided in as complete and accurate a condition as reasonably possible and, I've had that argument with many owners in government positions as well as private industry.  For the typical projects we bid, the construction cost could be in the range of 90% of the total project cost while the design ran around 10% of the total project cost.  Wouldn't it benefit the owner to have as complete and accurate as possible a design that adds to the 10% figure rather than risk changes later in the project that increase the cost of the 90% and delayed completion?  That theory of course depends on the procurement method where a design-build contract would have a very different understanding of initial design status than a design-bid-build contract method.

    Just a few thoughts from a retired engineer who spent most of his career working for subcontractors and general contractors.



    ------------------------------
    Stanley Bujalski P.E., M.ASCE
    Retired
    Campton NH
    ------------------------------



  • 18.  RE: Coordinates for Layout

    Posted 02-21-2018 04:34 PM
    As a VP for a large NYC Construction firm, we do see a major shift in layout on projects based on the availability of data in many new, and accurate formats.  GPS in Surveying, along with BIM modeling have really shot the industry forward in terms of how we CAN coordinate on site, but there are limitations (as I am seeing here in this thread), based on who is ultimately responsible for dimensioning and coordination.  We normally sign agreements that relieve the designer of coordination mistakes, since to be honest, as a CM, that's what we are hired to do (although we usually don't like to admit it so freely).  Seeing that the technology is, and can be, SO GOOD for a project, we release the designers, and then bring them into any discussions we have regarding coordination.  We continue to make them part of the coordination process, and 9 out of 10 engineers / architects we deal with, have no problem spending a few hours on the jobsite with our surveyor, and our subcontractors to figure out any discrepancies.  As long as we preach the mentality of "all in the boat" together, it generally works out, and the client gets what they ultimately deserve, a fully coordinated process.

    ------------------------------
    Robert Cortiglia
    BSCE / MBA
    Garden City NY
    ------------------------------



  • 19.  RE: Coordinates for Layout

    Posted 02-28-2018 10:17 AM
    I appreciate Stanley's perspective.  In my experience, providing electronic files (or using coordinates to locate a specific point) has always been in ADDITION to the usual distance/bearing information (tied to known section corners) and station/offset.  The electronic files are also considered non-contractual, and only certain files are made available prior to bidding by a Contractor (say, an ASCII alignment or cross-section report).  The intent on the public client's behalf is to be able to provide opportunity for Contractors of all sizes to be able to bid a project.  Typically, the Contractors chasing large, complex projects are more technologically sophisticated and also don't always bid on smaller projects where the Contractors bidding may NOT be using GPS.  For critical elements (abutment pile locations, control points, benchmarks) of construction, verification/confirmation survey by a second surveyor (contracted with the OWNER or the owner's construction inspection consultant) can be beneficial regardless of whether the Contractor's surveyor is using GPS, a total station, a theodolite, or a transit and chains.  And yes, for some public clients, there are local Contractors who use surveyors without GPS capabilities.  

    The question of what information is protected by the Engineer's seal is somewhat difficult as not all data formats can be "sealed" and still remain portable.  Again, for client's I've worked with, the "paper" plan set (PDFs usually, sealed by digital certificate) is the contract document and any electronic data is usually released under a signed disclaimer that says as much.  What is it they say in the intelligence community? Trust, but verify?  QC practices don't start and end with the designer.

    ------------------------------
    Kensey Russell P.E., M.ASCE
    HNTB
    Oklahoma City OK
    ------------------------------



  • 20.  RE: Coordinates for Layout

    Posted 02-21-2018 05:16 PM

    The use of coordinates increased as CAD became common place. The question is generally whether their use is appropriate on a given project. Coordinates are a bit like schedules (tables) in plans and specifications. If thoroughly quality controlled they'd work perfectly without dimensions, that of course would only work in a perfect world. As Shelly alludes to it is the dimensions that allow the Owner and Contractor to confirm the design intent of the Engineer. The goal is after all a successful project. Proper dimensioning of a layout, with some coordinates to allow the Contractors surveyor to quickly complete initial staking or locate corners of individual components of the work is good practice.

    Transmittal of electronic files requires caution. Our product designs in most jurisdictions bear a seal. Laws typically place the responsibility for restricting access to the sealed editable design files on the Engineer. Thus, while we may allow distribution of the design or related model files after removal of the seals, paper (or PDF) designs aren't going away soon. It must remain the Contractor's responsibility interpret the electronic data and determine if it matches the sealed design he/she agreed to complete when signing the construction contract. We should resist the temptation to free distribute editable files, there must be a reason behind the Contractor's request. Hopefully one that clearly increases his/her efficiency such as their use in driving grading equipment.



    ------------------------------
    Rosser Standifer P.E., M.ASCE
    Senior Project Manager - Conveyance
    Alan Plummer Associates, Inc.
    Dallas TX
    ------------------------------



  • 21.  RE: Coordinates for Layout

    Posted 02-22-2018 08:37 PM
    ​I think there is a big difference between a green-field project and a project involving existing structures, where all details and dimensions may not be completely discoverable until during construction. Regardless, Denis O'Malley asked how we can convince our clients to pay for additional efforts to make drawings more complete.  The question is not how to convince our clients, but how to convince the design community that it is not acceptable practice to provide less comprehensive plan sets.  If we don't agree on the minimum acceptable level of work product, the one with the lowest standards is the one who wins the project and lowers owner expectations.  This devalues all engineering.

    ------------------------------
    Michael Byle P.E., D.GE, F.ASCE
    Tetra Tech Inc.,
    Langhorne PA
    ------------------------------



  • 22.  RE: Coordinates for Layout

    Posted 02-23-2018 11:31 AM
    Edited by Tirza Austin 02-23-2018 11:30 AM
    I run into this all the time. Owner has no money but expects contrat documents to be accurate within a foot! I agree that producing drawings with inaccurate information at a lower cost just means change orders down the road for the contractor.





  • 23.  RE: Coordinates for Layout

    Posted 02-23-2018 11:31 AM
    ​Recall that old Manual 45 advised that fees should be at least 35% higher for work involving existing structures.
    Although the courts erroneously ruled the curves relating engineering costs to construction costs to be unlawful price fixing, the information in 45 is still valuable.

    ------------------------------
    Karl Sieg P.E., M.ASCE
    Sieg & Associates Inc
    Wexford PA
    ------------------------------



  • 24.  RE: Coordinates for Layout

    Posted 02-26-2018 09:56 AM
    In my experience, there is a positive correlation between those who resist providing accurate (read CAD) plans and those who want to charge extra for fixing design problems during construction.  Although it can not always be expected in an atmosphere of Engineer selection by less than knowledgeable officials instead of the owner's (or truly independent) engineers to afford competent designers, at some point it will have to be acknowledged by upper management that cheapest is not always the best bang for the buck, as engineering costs are typically only 10% to 20% of construction costs. 
         It is not that rare for construction extras to exceed design costs.  Back-calculating station/offset from lat/long is just not that difficult.
        Of course it should always be mandated for the Contractor to confirm geometry by a Surveyor (and underground utility locations) prior to beginning Work, which should negate idle equipment time extra charges.

    ------------------------------
    Stephen Hemphill
    Rio Rancho NM
    ------------------------------



  • 25.  RE: Coordinates for Layout

    Posted 02-27-2018 10:09 AM
    Good work





  • 26.  RE: Coordinates for Layout

    Posted 02-27-2018 02:19 PM
    Edited by Tirza Austin 02-27-2018 02:18 PM
    The challenge in providing electronic documentation is the change in mind set all around.
    Using paper documents there is an established procedure where all the checking points for accuracy are accepted both during design and construction.  Within this qc frame work acceptable time lines for providing information are known.  With electronic information provided the checking that was done during construction is not as thorough,  The contract drawings are now expected to have the accuracy that was expected for large scale details to be carried to the plans.  For complex structures that means locations have to be drawn to the mm (0.04 in).  The computing power to tie all the details into the plans on large projects is not there.  Also the need to provide and pay for time to carry out all the impacts of a dimensional change is not recognized.   

    In the case I mentioned earlier, the information on the change would have taken 40 hours of work to revise the complete plans and details.  We were provided with it 24 hours prior to tender with the statement it should not be any extra design cost.  The large scale details could be fixed in that time but the pile locations could not be moved on the plans.  However the pile locations using the plans and large scale details could be located.

    The Construction Manager only gave the plans to the surveyor.

    The point I am trying to make, is that there has to be a change in Mindset of everyone involved (owners, consultants and both general and sub contractors) on how to work out the time lines and costs in doing electronic projects.

    ------------------------------
    David Thompson P.E., M.ASCE
    Principal
    KTA Structural Engineers Ltd.
    Calgary AB
    ------------------------------



  • 27.  RE: Coordinates for Layout

    Posted 02-28-2018 10:14 AM
    This is an old subject that I first dealt with back in the mid-80's when CAD was in it's infancy.  I am really surprised that ASCE hasn't seen fit to address the issue directly.

    The real issue here is, what did the Engineer of Record Certify as his design?  If the EOR actually prepared the CAD files, and is confident enough of his ability to do so, then he may decide to release his/her files for more detailed construction reference, such as stake-out.  But if he reviewed the paper plans generated by CAD staff, and approved only the visual representation of the proposed construction, with annotations as to layout, etc., then you have another situation.  Issuing the CAD files for stake-out means the CAD Technician is now the designer of the project.  If a feature is to be constructed 10 feet parallel to another feature or property line, and the notation says so, but the CAD Technician fudged his drawing such that the coordinates say that it will be 9.75 feet parallel, and the CAD file is used for stake-out, then the construction would not comply with the EOR's design, for example.  The EOR would never have known that the drawing was wrong.

    Design surveys have been containing errors since the dawn of engineering design.  It happens, and can't be avoided.  But the careful layout of a project based on the EOR's design will usually result in the identification of those errors, and provide an opportunity for correction.  The exclusive use of CAD files only serves to cover up those design survey flaws and result in a completed project that may not be what anyone wanted.

    Since the advent of computers in design, there has been a tendency to accept the computer output as defacto and correct.  I have had to send young engineers back to the drawing board many times when their results were obviously off by a significant amount, such as 3 decimal places in computing stormwater volume - something they never even looked at, because "The computer said so".  Computers must be used carefully as a tool for design.  We still aren't to a point where the computer can d the design.

    ------------------------------
    Joseph Brown P.E., M.ASCE
    Engineering Consultant, Retired
    Tallahassee FL
    ------------------------------



  • 28.  RE: Coordinates for Layout

    Posted 02-28-2018 10:16 AM
    ​Being on the Municipal side I review a lot of plans and I have seen the trend toward less and less annotation and dimensioning on plans. Having worked in construction I have always believed that an approved set of plans should have all the information necessary to build a project from start to finish. The fact of the matter for me has always been that the people who actually build things in the field are usually somewhat removed from the folks in the office/trailer that can use CAD, GPS, or a total station. It seems like the world comes to an end the day the field engineer, superintendent, or savvy foreman doesn't make it to work. I kick back a lot of plans that don't have sufficient information to construct to the designers intent and personally try to include as many notes, details, callouts, dimensions, and point tables as I can on my own work.

    ------------------------------
    Adam Leach P.E., M.ASCE
    City Engineer
    La Vergne TN
    ------------------------------