THE STRESS POINT

April 2021 Volume 33, Issue 1

A Message from the Chief Engineer

Dear Friends,

As I write this note it has been over a year since the COVID-19 lockdown was initiated, subjecting all of us to personal, professional and financial burdens during the course of 2020. However, with the decline of cases toward the end of last year and mass vaccinations, 2021 is looking promising and I am optimistic that life will be somewhat back to “normal” in a few months.

Although we here in New England are in the midst of spring, the lingering effects of Old Man Winter remain as the Firm continues to receive investigations of freeze-up claims that took place a couple of months ago. Our neighbors to the south, who enjoy warmer climates, are not immune from the periodic “polar vortexes” that are sent down from the Arctic as we saw with the devastation experienced by Texas in February. HVAC systems are especially vulnerable to extreme ambient conditions that often result in extensive water damage to large commercial buildings. Tom Dombrowski provides insight as to the various reasons, some obvious and some not so obvious, for HVAC coil freezing, especially in locations where low ambient temperatures are expected.

In addition to HVAC systems, the mechanical engineers at the Firm have a wide range of expertise beyond mechanical systems. Although welding is a common means of joining metal items that we use every day such as cars and bridges, many people are not aware of how the welding process works or the different means used to weld metals. Jim Middleton provides an introduction into the welding process and the various techniques used to weld metals. Many times, our mechanical engineers are required to sort out equipment malfunctions that are alleged to be due to some prior repair effort, or a cause that appears to be obvious. To quote Mark Twain, "Truth is stranger than fiction, but it is because fiction is obliged to stick to possibilities; truth isn’t". As Wayne Maltry explains, there was plenty of “fiction” involving “possibilities” in a truck rollover case that he investigated. The truth, which was stranger than the possibilities, required physical observations, calculations and metallurgical data to get to the real reason that the accident took place.

Regards,

Thomas D. Traubert, P.E. | Chief Engineer, Vice President, and District Engineering Manager

FEATURED ARTICLE:

6-10 WHEEL SEPARATION

A left-rear wheel separated from a bucket truck while being driven on an interstate highway. The driver lost control and rolled the truck as a result.

IN THIS ISSUE

2 A MESSAGE FROM THE CHIEF ENGINEER | Thomas D. Traubert, P.E.

4-5 WELDING PROCESS | James I. Middleton Jr., M.E., P.E.

6-10 WHEEL SEPARATION | G. Wayne Maltry, AMT, BSAE, M.S.M.E., P.E.

11-13 FREEZE PROTECTION OF HVAC COILS | Thomas W. Dombrowski, P.E., CFEI

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