Ice Load Measurement on Molikpaq: Methodology and Accuracy

The Molikpaq deployment at Amauligak I-65 (ept/85-July/86) provides important data on icestructure interaction, for broad structures, because of the magnitude and type of interactions experienced. Although studied in depth twenty five years ago, the data has come into recent focus with further studies for development of the Amauligak discovery. But, what has become obscured and/or forgotten after twenty five years is the way ice loads on the Molikpaq were measured and recorded – there is both more detail and greater accuracy than apparently appreciated, but also limitations because of shortfalls in measurements during the first part of that winter. This paper describes the instrumentation and data acquisition systems installed in 1983-4, the upgrading of the instrumentation during 1986, and summarizes the extensive calibration work subsequently undertaken during 1986-9. An example of the measured ice loads is presented for a complete event (12 May 86) for which particularly simple conditions allow an independent assessment of ice load magnitude. The uncertainties in measured ice loads are discussed.