CFHT Dome Ventilation

Sitting atop the summit of Mauna Kea at a 13,800-foot elevation on the big island of Hawai’i, the CFHT (Canada-France-Hawaii Telescope) Observatory is an astronomical facility that houses a 3.6 meter optical / infrared telescope. Scientific research and wind-flow studies generated by CFHT led to their pursuit of a dome ventilation system that minimizes dome seeing and fully exploits the potential of Mauna Kea and telescope capabilities.

M3’s scope of work was to design a ventilation unit that fit within the existing dome structure without impacting the structural integrity. Installation requirements mandated that CFHT needed to remain in operation during on-site fit up and integration.

M3’S design successfully delivered a product that worked well with the fabrication and installation requirements and challenges. M3 as part of a design-build team worked closely with the fabricator, erector and CFHT providing an economical and practical approach to the fabrication and erection of all units on-site.

As it was necessary to cut into the existing dome skin, extensive research and analysis of the steel structure was performed to validate the introduction of ventilation assembly units. A finite element analysis was completed to validate the design and provide a feasible approach to the new steel elements as well as verification of all the developed stresses in the existing structure.

Due to the remoteness and severe weather conditions, all 12 ventilation units were designed to ship and arrive on-site ready for fit-up. M3’s design allowed the contractor to cut the existing dome skin, lift the ventilation units in place at a rate of one per day minimizing the risk of inclement weather issues.

The project benefited from the collaboration between CFHT, contractors and M3, and was commended on how well the ventilation units fit to the existing dome appearance.