About Roger L. Martinez

Assistant Professor of History University of Colorado at Colorado Springs

9 November 2012 Update

This week the HES met to:

  • review the results of the stress testing of oak and douglas fir wood samples,
  • evaluate the latest design of the release mechanism,
  • discuss fundraising priorities, and
  • determine the timing of ordering building materials.

Images from the stress testing of the wood samples:

Laser cutting wood samples

Wood sample ready for stress testing.

Wood sample under stress testing

The results of from our stress testing of actual wood samples are as follows:

Specimen and orientation AKI’s Researched Values Material Tests Done by Ben
Pine Parallel to grain in Tension 107.6 MPa(114.5,16.89 63.5 MPa(67.57,9.96)
Pine Parallel to grain in Shear Tension 7.8 MPa(43.8,1.22) 21.5 MPa(120.7,3.36)
Pine Perpendicular to grain Tension 1.92 MPa
Pine Parallel to grain compression 49.9 MPa (42.3,7.38) 41.25 MPa(34.9,6.1)
Pine Perpendicular to grain compression 7.29 MPa
Pine Parallel to grain shear compression 24.41MPa
Pine Perpendicular to grain shear compression 5.67 MPa
Oak Parallel Tension 77.9 MPa(82.8,12.23) 43.6 MPa(46.43,6.84)
Oak Perpendicular Tension 6.35 MPa
Oak Shear Parallel 12.5 MPa(70.2,1.96) 37.39 MPa(209.98,5.86)
Oak Parallel Compression 41.8 MPa(35.4,6.56) 55.03 MPa(46.6,8.63)
Oak Perpendicular Compression 16.22 MPa

Safety Factor ≈ (Static, Dynamic)


UCCS History Department

Sean Potter, an undergraduate history student who is enrolled in HIST 4150: Astrolabes, Arms, and Azulejos: Medieval Science, Technology, and Material Culture, located a web posting relating to a modern LEGO reproduction of the Antikythera mechanism. This posting is particularly intriguing as several students in HIST 4150 will be creating reproductions of medieval devices and technologies this semester. Hopefully, they will be inspired by this LEGO model.

So, what is the Antikythera mechanism?

According to Encyclopedia Britannica,

[It was an] ancient Greek mechanical device used to calculate and display information about astronomical phenomena. The remains of this ancient “computer,” now on display in the National Archaeological Museum in Athens, were recovered in 1901 from the wreck of a trading ship that sank in the first half of the 1st century bce, near the island of Antikythera in the Mediterranean Sea. Its manufacture is currently dated to 100 bce, give…

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Goal: Build a Medieval Trebuchet

The UCCS Historical Engineering Society (HES), an official UCCS student-driven organization with faculty advisers, endeavors to build a 20-percent scale model “Conrad Kyeser Trebuchet” as a demonstration project to inform the public on the engineering feats of the medieval world. A trebuchet is a medieval siege weapon, similar to a catapult, which uses a counterweight to launch projectiles to destroy castle walls and fortifications. Trebuchets were the “super” weapons of the Middle Ages, especially from the 12th through 15th centuries. During this time period, trebuchets were developed via cultural exchange between Christian European kingdoms and Islamic caliphates in the Mediterranean world.

The goals of “The Trebuchet Challenge” project are to promote and enhance students’ historical research, design, engineering, and leadership skills. In the interest of fulfilling these goals, and others, we hope to complete construction of the trebuchet by September 2012. Now in the process of completing a five-stage research-to-demonstration work process, the HES has already completed its historical research, developed detailed computer-aided design (CAD) drawings, and evaluated the safety of the design using a design review panel composed of three UCCS engineering professors.

However, in order to construct and demonstrate the trebuchet (Stages 4 and 5 of the project) we require approximately $3,745 in financial and material donations. Over 50 percent of our budget is dedicated to purchasing an expensive oak beam that will serve as the machine’s 12-foot throwing arm.  For historic, strength, and safety reasons, it is absolutely essential that a hardwood such as oak be employed for the throwing arm.

The HES seeks funding from private, small business, and corporate donors in the Colorado Springs region. Funders are encouraged to contribute at varying sponsorship levels ranging from $25 to $1,000.  The sponsorship levels are tied to medieval social and political stations, i.e. king, prince, duke, knight, and squire sponsorships. Those businesses that choose to donate will receive recognition at every event at which the trebuchet is present.  Forms of recognition include, but are not limited to, donor name on display at every event, donor name on flyers advertising upcoming events, and donor name on display beside the trebuchet at the UCCS Heller Center for the Humanities, where the trebuchet will be kept when not in use. The two future stages of the project can only be made possible by generous donations from our community and without their help the realization of our goals and efforts will be impossible.