Figure 1

Figure 2

Figure 3

For most of my professional career, I have had the opportunity to serve on various code committees. For example, I became a member of the AWS D1 Structural Welding Committee in 1959 and now serve as an advisor.

It has been a privilege to serve on these committees with my colleagues, and I'm pleased to have contributed to the content of industry standards. Therefore, my subject this month is not a criticism of such standards, but rather reflects a reality of the code-writing process: Codes often lag practice.

Let me explain with a couple of real examples.

Many years ago, a major structural steel fabricator had a contract to fabricate some large steel box columns. The design called for partial joint penetration groove welds in the corners. This contractor decided that the lowest cost partial joint penetration PJP weld detail was a U-groove, and decided to prepare the cavity by automatic air arc gouging.

The typical practice was to prepare a J groove on the edge of each plate, and then to assemble the four pieces into a box. However, when this had been done in the past, the root was not always consistent (see Figure 1). This time, the fabricator decided to assemble the box first, and then to gouge the grooves. Not only would this approach reduce preparation time, but it would achieve a consistent root condition, as shown in Figure 2.

The contractor had just begun fabrication when the welding inspector objected to this practice, indicating that it was not permitted in the AWS D1.1 Structural Welding Code—Steel. The inspector, however, could not find any words in the code that prohibited the practice. He contacted AWS and suggested that the Structural Welding Committee incorporate into the code specific language that would prohibit such practices so that this situation would not happen again.

The committee considered the request, but came to the opposite conclusion: that the code should be modified to clearly permit this practice. The change was made many years ago, but the specific provision in D1.1:2006 is as follows:

3.12.3 Joint Dimensions
(3) J- and U-grooves may be prepared before or after assembly.

The welding inspector was incorrect in his application of the code: Failure of the code to permit something does not necessarily equal prohibition. The committee decided that this was actually a good practice, and one that should be specifically permitted, and thus changed D1.1 to make it clear that this practice was acceptable.

How and why did this code change come about? It happened because it was already being done in practice and with successful results. Thus, "codes often lag practice."

The second example involves an early example of welded bridge girders. It may seem strange today given the widespread acceptance of welded plate girders for bridge applications, but back in the 1940s, riveting was king and welding was a new fangled method that was viewed with jaundiced eyes by some state bridge engineers. This skepticism was reflected in the 1949 American Association of State Highway Transportation Officials (AASHTO) Specifications.

At the time, I knew that several states were already using all-welded plate girder bridges. I wrote to the bridge engineer of one of these states and asked him how it was that they had been welding their bridges for several years, although AASHTO apparently had not given a green light for welded girders. He replied by saying "You have to have the courage of your convictions and do what you think is right." By 1953, the AASHTO Specifications had been changed to reflect this practice. See Figure 3.

Most codes permit alternative practices when they are approved by the governing authority. In the case of the second example, the bridge engineer I contacted was a pioneer who was prepared to embrace an emerging technology before his colleagues who were writing the specifications were ready to include welded plate girders in their list of acceptable applications.

In reality, governing codes are likely to be one or two steps behind what is already in practice. This is not necessarily bad. A history of successful usage is often essential before the code writers will incorporate new materials or practices into the standards. In the interim, those with the authority and responsibility to approve or disapprove code alternatives must carefully scrutinize and fully evaluate new practices before officially accepting or rejecting them. Great caution should be exercised, and irresponsible ideas must be disallowed. However, new approaches should not be rejected out of hand simply because they "are not in the code".

Perhaps there is a new technology that you would like to use, even though it isn't "in the code." Today, we have new steels, new filler metals, new power supplies, new wire feeder controls, digital communication between welding machines and computers, robots, new weld inspection technology—the list could go on.

Unsurprisingly, many of these innovations have yet to be incorporated into codes. Don't let the lack of code coverage be the only barrier to implementation of your ideas. Appeal to the governing authority, armed with the data needed for a complete analysis of the alternative. If the material or practice is embraced by the code writers, you will have made a valuable contribution.

Omer W. Blodgett, Sc.D., P.E., senior design consultant with The Lincoln Electric Co., struck his first arc on his grandfather's welder at the age of ten. He is the author of Design of Welded Structures and Design of Weldments, and an internationally recognized expert in the field of weld design. In 1999, Blodgett was named one of the "Top 125 People of the Past 125 Years" by Engineering News Record. Blodgett may be reached at (216) 383-2225.