• Uncategorized 30.08.2012

    In Paul Newman’s movie “Cool Hand Luke,” the warden famously tells the prisoner, Luke: “What we’ve got here is failure to communicate.” Do you ever feel like that? Whether in words or drawings, meanings sometimes get muddled. Here are some observations on communicating clearly, especially in shop drawings.

    Recently, when writing about what I thought were basic industry terms, it became apparent that to the uninitiated, understanding the lingo is sometimes not as easy as one might think. While terms like “screw-spline connections,” “shear block construction,” “moment splice,” etc., are common in glazing, have you ever tried to explain to someone what they mean? In writing, especially writing that will be translated to another language?

    When it comes to jargon, I remember when I first heard the term “shop drawings.” It was in a construction management class at architecture school in which we were discussing how various subcontractors have to submit their interpretation of the contract documents, including for the drawings and specifications, and put down in drawing form exactly what they plan to build, supply and/or install on a given project.

    It wasn’t until I got my first job in the glazing industry that I learned just how that applied to glass curtainwalls and windows. To me, lockstrip neoprene gasketed curtainwalls are like mother’s milk: they were what I was raised on, and what that company did for a living. To execute the work we drew every detail. The philosophy was that the field crews shouldn’t need to have any drills or saws in their tool buckets since every piece could be more easily fabricated in the shop. So we spent a lot of time on shop drawings, detailing every aspect of a given curtainwall. My first project had an extruded lighting track, with big, glass-jar lites spaced out along every corner, across every parapet, soffit and coping. I got to detail a lot of that.

    I admit to being somewhat anal about what constitutes a good set of shop drawings. In their simplest form, the primary purpose of shop drawings is to facilitate the manufacturing and installation of the window or wall system by the glazing subcontractor and their supplier(s). So, much of what is detailed is strictly for those functions. Once approved, the drawings convey a message on how the wall will look when the installation is complete.

    This is where the rubber first hits the road (or the glass hits the gasket, as the case may be): in many instances, the first “product” shipped by a curtainwall supplier or installer is the set of shop drawings produced for the job. And the reason they’re submitted and reviewed is that other parties to the project need and use them, and therefore the drawings become communication tools to those other parties.

    Those other parties are by no means small potatoes to a project. The shop drawings are used by:

    1. The architect and their consultants, to primarily check for compliance for design and technical adequacy of the proposed systems with the contract documents.

    2. The general contractor to coordinate the curtainwall and/or window wall work with adjacent trades and scheduling or coordinating who does what, when.

    3. Those affected other trades.

    4. A structural engineer to confirm the loads imposed on the building frame at anchor points are not overloading those components.

    5. The fabricators as the basis for completing:

    a. Material take offs;

    b. Fabrication drawings;

    c. Which parts are “shop applied” to other parts before shipping, and which parts are “shipped loose” directly to the job;

    d. How those parts are bundled (e.g., by floor? by area?), and when are they shipped to the site; and

    e. The actual cutting, notching, drilling, general machining and partial assembly (as necessary) for any/all of the parts.

    6. The installing contractor, who must use them for:

    a. Layout dimensions, datum elevations, opening dimensions, etc., specifically identifying where the material is to be installed;

    b. Field requirements: what equipment is needed to install the material;

    c. How to staff the job: how many crews, how fast can material be set, etc., that determines the schedule;

    d. Layout and storage needs: when will material be delivered, how often, where it’s going to be stored on site, etc.;

    e. If/when will a crane be required; and

    f. And, most importantly, specific instructions for installations NOT covered in the typical “installation manual.”

    The point: shop drawings are communication tools. While many of the details in them might be completely for internal use, there are a lot of other operations/individuals that will use them for their own purposes. Thus, clarity is essential in order for the shops to be effective communication tools.

    The Glass Association of North America (GANA) is about to issue a bulletin that addresses what should be included in a good set of shop drawings. Start with that. Look at how your organization prepares and uses shop drawings, and see if there are things that would have been smoother on the last job had some aspect of the drawings been better. And, ask yourself if that change would be worth making an “SOP” for the next time?

    My first employer, Bill Swango, never wanted the field guys standing around scratching their heads about something that wasn’t covered in the shops. If the guys doing the installation have questions, they usually try to reason it out. Then if they can’t, they call their supervisor, who will call the office if he can’t straighten it out himself. Think of all the time and money that takes. Then the guy in the office has to figure it out anyway. Bill’s point was all of that could have been avoided if the guy in the office (often it’s the guy who did the shop drawings) figured it out, and put it on the shops in the first place).

    Good communication tools pay for themselves. Always have, always will. Shops are just another part of the equation each of us deals with on a regular basis.

    Posted by Blogger @ 12:27 pm

  • 3 Responses

    • Bill Lingnell says:

      Chuck,

      You have learned well and now you are advising and teaching in a similar manner. Keep up the good work. Yes,I remember those Swango days as he was definitely an advocate of the “attention to detail” concept, and we all know that without it things will not go as well.

      Bill

    • chuckk@tgpamerica.com says:

      Bill:

      Ah, the good old days… Thanks for the kind comments, knew there’d be some folks out there that get it.

    • Phil Kight says:

      Thank you for a great posting. I wondered how long this has been on the web, now I know. Anyway, your points concerning how so much time is wasted when even a good set of drawings would/could are the reasons I want to break away from installation and move to the drawing phase.

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