Accumulator Sizing and Hydraulic Architecture Challenges in Salter’s Duck

Accumulator Sizing and Buoyancy Constraints in Salter’s Duck: Engineering Analysis of the Edinburgh Wave Power Project’s Hydraulics

Abstract

The Edinburgh Wave Power Project, centered on Salter’s Duck, remains a landmark in wave energy converter (WEC) research. Despite its exceptional hydrodynamic efficiency, the project encountered a critical engineering barrier: the hydraulic power take-off (PTO) system’s accumulator sizing requirements for smoothing power in random seas would overburden the device’s buoyancy envelope. This paper presents a comprehensive analysis of this finding, including a numerical example of accumulator sizing for a Duck, an exploration of why random seas necessitate vast smoothing volumes, a comparison of hydraulic versus direct-drive PTO feasibility, and a reconstruction of the coronet hydraulic architecture with reference to later knuckle-joint designs. The discussion contextualizes these technical results within the historical narrative, showing how news articles claiming “they sank Salter’s Duck” were, in light of these engineering findings, accurate. The report draws on archival technical reports, academic literature, and contemporary engineering analyses to provide a rigorous, evidence-based account suitable for engrXiv.