Interview with the Cascade Bus Shelter's Engineer

Interview with the Cascade Bus Shelter’s Engineer

The “Cascade Series” Art Shelters represent the culmination of a successful collaboration between artist and engineer and are an innovative use of an unconventional material in the public works realm.

Walt Geiger, architect and artist, and John Marhoefer, Principle Engineer and CEO of Entech Creative Industrieswere part of the driving force behind the Art-in-Transit Initiative that introduced the functional art shelters.

The Cascade Series is composed of four separate works of art along International Drive around the Orlando Convention Center that are used as functional bus shelters for the local transit company.  Each is a compilation of two to five separate composite forms, each approximately three feet wide and fifteen to sixteen feet high, that together create shelter for bus riders from the intense heat and rain of central Florida.

Scale models to represent the possibilities for the series were constructed as part of the process before the final designs were selected. As with every project, cost was a consideration, and forms that proved too expensive to fabricate were eliminated.  Once the final designs were selected a laser scan was made, converting the forms into 3D CAD files. These were then scaled up and used to construct CNC’d molds into which spun fiberglass, resin, and honeycomb core would be laid.  Core thickness and lamination skin materials vary as needed on the various parts of the structures.  A main focus during construction was on perfecting the joining techniques.

In February of 2012, the Cascade Series civic functional art project was awarded the top prize by the ACMA in the category of Design: Most Creative Application.  The judges cited the projects accomplishments of advancing the use of composites into civil structures in a unique and creative manner.

I spoke with John recently about Cascade, and asked a few questions about the collaboration process and the issues in using composites for a public project like this:

Question:  Often when designers and fabricators collaborate on a project, issues arise due to the differences inherent in how these disciplines operate.  As your’s is a long-standing collaborative relationship, can you go into more detail on how you two work together?

John Marhoefer:  Walt and I have known each other for over almost 20 years now and met originally by our work in the theme park industry.  I think each of us recognized a similar ranging intellectual curiosity in each other and began an informal arrangement of idea sessions.  These sessions or meetings on many occasions consisted of each of us elucidating the other on our respective areas of expertise.  The ongoing commitment to the collaborative stemmed from an early recognition that together we were able to generate interesting ideas that we may never had come upon in isolation.  So while there are certainly differences in our disciplines, it was those differences that came to be the source of synergistic ideas.  The opportunities for cross-purposing means and methods common in one discipline or area to another in which those ideas were not being utilized seem to multiply at almost every occasion.

The art shelters are one example.  Walt has several theses in his vocation and avocations.  One is a commitment to art and another is community responsibility.  In our collaboration we were exploring the potential for use of a honeycomb core material for use in non-linear forms.  As the exploration developed Walt saw art forms in the structurally sound shapes that I came to know could be obtained.  Through a set of fortunate circumstances this work resulted in moving art into public spaces while simultaneously advancing the use of composites in civic structures.

Q:  Whenever a non-traditional material is proposed for a building or public space there can be a lot of additional work involved in order to convince those in charge of its viability.  Code issues make up a great deal of this struggle when it comes to building with FRP. What did Entech go through to get AHJ (authority having jurisdiction) approval for material choice?

JM:  There was a good deal of effort to accomplish this.  Composites are a relatively new building material in civil construction.  In fact as recently as 2006, the IBC (International Building Code) was entirely silent on the use of composites including FRP.  In this case a combination of analysis and full scale testing was employed to meet the requirements.  To the credit of building code groups and building officials and to the benefit of the public, the use of composites is slowly being accepted more and more.

Q:  Do you think it is being accepted too slowly?

No I don’t think so.  Civil construction is rightly approached from a very conservative view.  The standard of care is very high.  So while composites have been utilized in other industries with increasing prevalence for decades, as a building material for civil works, composites is still in the very early stages of adoption.  By contrast, take note of the fact that the ancient Romans utilized Portland cement, a now-centuries-old core building material widely used today.

The field of composites, along with being relatively young, is incredibly diverse so it will take many years of academic and industry testing and research before we can expect to see the parameters for composites use codified in the way we see, say, steel is today.  The frontier will get moved little by little- but it will get moved.  And it did in this project.

Q:  Entech Creative does a lot of the special forms found in amusement parks, many of which are made out of FRP, which caused me to realize that a great majority of what we see walking around a place like Disney World is made out of FRP.  Do you think these applications help in convincing people on the merits of FRP for other applications in the built environment?

JM:  I suppose so but I believe that the issue involving adoption into the building codes is one other than a belief that FRP is a useful material.  Theme parks are in effect special development areas with a foot so-to-speak in more than one camp.  Certainly there is the jurisdictional control of the local building officials but with respect to ride/attraction development in most states that falls within a separate purview – the department of agriculture in Florida for example.

I do believe it likely that building officials exposed to theme park development may be more likely to consider the merits of composites as they are necessarily very often integrated into the developments.  Still, in the parks, composites are almost exclusively cladding or components and are not part of the primary building structure.  The applicable standards for rides though, most often based upon ASTM requirements, are such that the use of composites is much more established.

 Q:  Any upcoming projects?

JM:  Lots and lots on the table.  The one I’m currently very excited about is the development of a disaster relief shelter that would be inexpensive, quick to make and install, and easy to ship.  I think what will make this be able to happen is the again the use of a composite.

We look forward to news of what will surely be many more groundbreaking projects from Entech Creative!

©2011 Walt Geiger Studios LLC, Raymond Martinot, photographer