Advancing Technology

As a new school year begins, it makes me think back to my first year at Virginia Tech (which by the way was called Virginia Polytechnic Institute and State University at the time).  It was the first year that the slide rule was not used anymore and it was required to have an electronic calculator.  I had an approved Rockwell that could do amazing things like sine, cosine, and tangent without the use of a CRC table of values.  I’m sure some of the professors were grumbling about the introduction of calculators.  

We were exposed to that new-fangled machine, the computer.  We had to type out key punch cards to develop our exciting program that would count from 1 to 10.  In order to do this we had to find a key punch machine on campus, type our program in Fortran, and hand the cards to our professor.  He would then take the cards to a compiler to get our results. Usually on the first pass there was a card punch error, a hanging chad, and we would have to retype the card.  Later in my college career we befriended some physics students who had a compiler in their building, this allowed us to bypass the crowded compiler in the computer center.  

As I reflect back on those days, it amazes me how far technology has come throughout my career. Now there is a computer on every desk and my phone has more computing capacity than all the computers combined in my days at Tech.  It has sped up the design process and allowed us to be more efficient in our work.  The models we create are far beyond anything we dreamed of in school.  Some people miss the good old days, but I am glad to be where we are and to have this technology at our fingertips.  Engineering has benefited greatly from the advances and I wonder what the next generation will have at their disposal for producing exciting designs.

Building in Belize

Imagine what it’s like for a structural engineer to go to a Central American country to help construct a classroom where there’s no real enforcement of building codes or standards. That’s what I just did!

I have been to Holy Cross Anglican School many times in the past, but this was the first time I have actually been involved in the erection of structural components. Our team set a 2 x 4 rafter that was 26 feet long with a splice point at 16 feet from the ridge. It was a hardwood 2 x 4, but it’s remarkable to me that it could span that far and still support the roof and a couple of people. This is standard practice for the area and does not affect life safety, so I jumped in to help build and erect it. The density of the hardwood makes nailing and cutting the wood interesting since most pieces required pre-drilling before nails could be set.

It was definitely a hard week of work, but it keeps me grounded and reminds me of how rough the workers in the field have it (especially those who do not use nail guns!). It is good practice for all engineers to swing a hammer and cut some wood from time to time; it gives us an appreciation that putting things down on paper (or on the computer) is much easier than putting it together in the field.

Atypical Engineering

I recently returned from Structural Specialist Training in California for the USACE and FEMA USAR system (there’s a lot of abbreviations for you!).  I am on the VA Task Force 2, USAR team and we respond to large scale disasters.  Having an engineer on the team keeps the Task Force members safe.

When responding, we often deal with structures that are in very unstable condition; this is a difficult mindset for engineers to operate in.  We are trained to make sure that the structures we design are able to withstand the design loads set forth in code, but in situations like these structures have severe damage and could fall down at any second.  The Task Force members do not need us to tell them that the building is unsafe, anyone could see that; they need us to explain to them the risks involved for potential further collapse and/or the safest way to enter and exit the building.  Additionally, we might have to develop a shoring plan to access any people that may be trapped in the building.

It is a very challenging, but rewarding form of engineering and I am very proud to be able to call myself a member of a very select group of engineers in the FEMA USAR and USACE system.

Real World Issues with Lateral Loads

One of the hardest things we have to do as structural engineers is explain to builders/contractors why something that they know they can build in the field will not work when we design it on paper.  The following is a typical situation, we size a ridge beam for a cathedral ceiling and the framer tells me that he has never needed to do this before, either followed or preceded by, I have been doing this for at least 20 to 30 years. So here is the simplest explanation for why it seems that at times we make life difficult for contractors.

One main reason is the fact that we have to design for lateral loads, such as wind events and earthquakes. Gravity is present 100 percent of the time so a contractor is used to building for that force.  Design lateral events however, may span years between events or may never occur during a building’s life, so there is no intuitive development of what is needed to resist those forces.  One look at the devastation in Nepal shows that structures can withstand gravity loading for years, yet crumble under lateral loading.

The other variable we have to deal with is the actual connection of material; we model connections using either a pinned or a fixed condition.  In the field there is really no such thing as a pure pin, there is always some type of rotational restraint.  For example, with a nailed wood connection we can’t model a fixed connection until someone develops a way to weld wood together; I don’t think a pine tar welding rod is in our future.  

So when a structural engineer tells you something won’t work it is usually because the total lateral and gravity loads over-stress the structure or our model of the structure does not work.  We are here to prevent things from falling down and to remain usable even after design loading occurs.  The end goal is to work with builders and contractors to make sure that the buildings we create are usable and safe for years to come.

The Good Old Days or The Day of Yore

I was talking with a fellow silver-haired, or more correctly, grey-haired fellow the other day about the good old days.  It seems that structural engineering, like life in general, gets more complex year by year.  When I started out in the business the thought of reinforcing masonry was a new concept, wind design was applied only to tall buildings, and a computer was something that the giant firms and universities had access to.  Most contractors did the majority of the work themselves, requiring only a few subcontractors.  My engineering class was the first class to require a hand held calculator, costing upwards of $200; who knows what that would mean in today’s dollars.  It was a different time and so much has changed.

There have been a lot of positives in the time since I have begun the practice of engineering.  The computers have revolutionized economies in design and drafting and communication avenues are better and faster, but are we building better structures?  In some ways yes and in some ways no, but I am sure each generation will look back to the days of yore.  I wonder what the next generation will have to say about the good old days.

Carter Sinclair, April 1987

Palapa Structure

I have just returned from Mexico, escaping the snow and the cold for a 10 day stay. My wife and I took a side trip to a small island on the Gulf Coast called Holbox. While there we stayed in a palapa that was totally constructed using local materials. The palapa is a native structure that is usually round with a peaked roof. The basic frame consisted of wood posts sunk into the ground with a raised wooden platform. The walls were infilled with adobe. The roof system consisted of probably 5 inch diameter wood poles running to the peak with lateral purlins of wood only 1 inch in diameter, spaced at around 16 inches on center. The roofing material was a grass material laced into the purlins with twine. I am sure that no licensed engineer was involved in the project. However the structure and others like it have survived at least two major hurricanes in the past 20 years that have struck the Yucatan Peninsula. I am sure there was some repair to be done, however the structures are still standing.

This all made me think of how structural engineering has evolved through the millennia. We would build something and if it fell down, we would try again with either more materials or stronger materials. Structures evolved over time. In this modern age we can build wonderfully complex structures, but I wonder if sometimes we have lost the art and craft of building. The computers and codes tell us what we have to use, but at times we have lost sense of why things work and sometimes common sense seems to have gone out the proverbial window. I guess that is a sign of getting older and ruing about the olden days. As John Waller once told me he could produce a set of drawings for an Elementary School for Virginia Beach on 8 sheets and they were all still standing. I am thankful for all the design aids we have these days, but sometimes we need to remember exactly how we have reached this point in design and try to retain some of the art and craftsmanship.

2015: A Time of Change

Today’s blog has nothing to do with engineering, it is all about transition.  It is a time of transition here at Sinclair Pratt Cameron, as I say goodbye to two partners and welcome in four new partners.  It is amazing to me how time has passed by since the inception of this company. It was almost 30 years ago that Dan Cameron, Dave Pratt, and I ventured out in the formation of a new company.  I say goodbye to two wonderful partners, but I do not have to say goodbye to their friendship; that will continue on into the future.  I welcome in the partnership of Chris Sterne, Marla Godwin, Shawn Maslaney, and Kevin Rainey.  They have been valuable employees and now they put on ownership hats.  It is a time of transition and a time of excitement.  I myself am looking forward to a very exciting 2015.

- Carter Sinclair

Left to right: Chris Sterne, Marla Godwin, Kevin Rainey, Shawn Maslaney, Carter Sinclair.