Steel detailer
From Wikipedia, the free encyclopedia
A steel detailer is a person who produces detailed drawings for steel fabricators and steel erectors. The detailer prepares detailed plans, drawings and other documents for the manufacture and erection of steel members (columns, beams, braces, trusses, stairs, handrails, joists, metal decking, etc.) used in the construction of buildings, bridges, industrial plants, and nonbuilding structures. A steel detailer's projects are usually commercial, industrial or municipal; residential projects are rarely large enough to require significant amounts of structural steel.
Steel detailers (usually simply called detailers within their field) work closely with architects, engineers, general contractors and steel fabricators. They usually find employment with steel fabricators, engineering firms, or independent steel detailing companies. Steel detailing companies and self-employed detailers subcontract primarily to steel fabricators and sometimes to general contractors and engineers.
Contents |
[edit] Training and certification
[edit] USA
Collegiate degree programs specific to structural steel detailing are rare to nonexistent in the U.S., but more general degree and certification programs may be found with curricula pertaining to design, manual or computer-aided drafting in general, or specific computer-aided drafting software. A college degree is not required to become a steel detailer in the U.S. Training is usually provided on the job, with a new trainee usually needing about five years of practice under an experienced detailer to become proficient with all of the requirements of the trade. Practitioners of this occupation in the U.S. may range from degreed, and possibly licensed, civil/structural engineers to those with little or no formal academic training who nevertheless possess extensive industry experience.
Certification of structural steel detailers is not required in the United States. The National Institute of Steel Detailing (NISD) offers a selection of certification programs for steel detailers and detailing companies, but these are strictly voluntary.
[edit] Responsibilities
All steel members required to build the structure are fabricated and erected from shop and erection drawings created by the structural steel detailer.
The steel detailer creates his drawings based on information presented on design drawings created by a structural engineer (structural design drawings) and/or architect (architectural design drawings). The design drawings may also include information related to mechanical systems which is relevant to the fabrication of structural members, and which must necessarily be incorporated by the steel detailer. In the case of buildings, this information is typically related to HVAC design, but in the case of industrial projects may generally include information relating to the ultimate industrial purpose, such as pumps, piping, material handling equipment, and other types of industrial machinery and equipment. The total package of design drawings contains information relevant to all trades, and the detailer must coordinate and extract the information required to generate detailed shop drawings usable by the steel fabricator. The design drawings show information in a general way, such as material sizes and connection requirements, and it is the detailer's responsibility to translate these general requirements (the "design intent") into detailed drawings for each specific steel member in the structure. In this way the detailer acts as an interpreter of the design drawings for the fabricator.
A steel detailer prepares two primary types of drawings: erection drawings and shop drawings.
Erection drawings are used to guide the steel erector on the construction site ("in the field") as to where and how to erect the fabricated steel members. These drawings usually show dimensioned plans to locate the steel members, and they often also show details with specific information and requirements, including all work that must be done in the field (such as bolting, welding or installing wedge anchors). Since the erection drawings are intended for use in the field, they contain very little specific information about the fabrication of any individual steel member; members should already be completed by the time the erection drawings are used.
Shop drawings, also called detail drawings, are used to specify the exact requirements for fabricating each individual member (or "piece") of a structure, and are used by the steel fabricator to fabricate these members. Complete shop drawings show material specifications, member sizes, all required dimensions, welding, bolting, surface preparation and painting requirements, and any other information required to describe each completed member. The shop drawings are intended for use by the fabrication shop, and thus contain little or no information about the erection and installation of the steel members they depict; this information belongs in the erection drawings.
The detailer must comply with the requirements of the design drawings and with all industry standards and protocols, such as those established by the American Institute of Steel Construction (AISC) and the American Welding Society (AWS). The detailer is not usually responsible for design, including structural strength and integrity (which are the responsibility of the structural engineer), major dimensions of the structure and compliance with relevant building codes (which are the responsibility of the architect). A detailer is generally required to submit his drawings to the structural engineer and/or architect for review prior to the release of drawings for fabrication. In the case of non-building projects there is typically no architect, and detail drawings are reviewed exclusively by the structural engineer of record. This design review ideally assures engineering accuracy and compliance with the design intent.
[edit] Techniques
Traditionally, steel detailing was accomplished via manual drafting methods, using pencils, paper, and drafting tools such as a parallel bar or drafting machine, triangles, templates of circles and other useful shapes, and mathematical tables, such as tables of logarithms and other useful calculational aids. Eventually, hand held calculators were incorporated into the traditional practice.
Today, manual drafting has been largely replaced by computer-aided drafting (CAD). A steel detailer using computer-aided methods creates his drawings on a computer, using software specifically designed for the purpose, and printing out his drawings on paper only when they are complete. Many detailers would add another classification for those using 3-D Modeling applications specifically designed for steel detailing, as the process for the production of drawings using these applications is markedly different from a 2-D drafting approach.
Structural steel detailing requires skills in drafting, mathematics (including geometry and trigonometry), logic, reasoning, spatial visualization, and communication. A basic knowledge of general engineering principles and the methods of structural and miscellaneous steel fabrication, however acquired, is essential to the practice of this discipline. A computer-aided detailer also requires skills in using computers and an understanding of the specific CAD software he is to use.
A detailer's drawings generally go through several phases. Following creation of the drawing, the detailer must usually (as described above) submit a copy of the drawing to the architect and engineer for review ("approval"). Copies of the drawing may be sent to other recipients at this time as well, such as the general contractor, for informational purposes only. The drawing must also be checked for accuracy and completeness by another detailer (for this purpose, the "checker"). Comments arising from approval and corrections made during checking must be resolved, and the original drawing must be updated accordingly (or "scrubbed"). After this, the drawing may be released to the fabricator and/or erector for use in construction.
