Design and install a robust 10m flagpoles

Harrisons were invited by Trinity College, Cambridge to design and engineer a new replacement flagpole for the Great Gate. This is the main entrance to the College and was built between 1519 and 1539. It is one of the most photographed parts of Trinity.

The 10m flagpole stands prominently on the top of the Great Gate. It is mounted on a tabernacle and has a uniquely designed finial at the top. The college flag is regularly flown. It is also a requirement for the flagpole to be robust enough to take the wind loads of the Royal Standard.

Harrisons surveyed the original pole and tabernacle detail to determine the most effective means to remove the existing pole and the correct design limitations for the new replacement. Generating site specific wind load calculations we designed a 10 metre stainless steel tapered flagpole. It was designed to fit into the existing tabernacle with the correct wall thickness to withstand the wind loadings required. Taking measurements from the original finial, we recreated a copy of the original but added a more robust double pulley system.

To safely remove the original pole and install the new flagpole, a crane was engaged to raise the poles above the tower. It was important to protect the Grade 1 listed Gate House and cobbled area in front. We worked closely with the College to ensure the design met the operating requirements. We also ensured the installation complied with the conservation orders to protect the 16^th Century cobbles in front of the Great Gate.