As part of a design upgrade for a series-built day racer, a racing yacht design studio asked us to investigate a recurring problem with the rudder mounting fittings. The studio wanted to understand why the original arrangement was malfunctioning before deciding what to change. We took the project from the initial investigation through structural analysis, redesign and delivery of the replacement fittings.
Following the loads through the rudder
We started by defining the load cases and calculating the forces acting on the rudder. We then traced how those forces were transferred through the rudder stock and into the mounting assembly.
Using finite element analysis (FEA), we modelled the rudder, stock and fittings to examine how the assembly behaved under the relevant loading conditions. We looked at how the loads were distributed, where stresses were concentrated and how the assembly behaved under the failure mode we were investigating. We also assessed fatigue to understand the effect of repeated loading over time.
Together, the calculations and simulations helped us identify the root cause and establish what the replacement fittings needed to withstand.
Redesigning and verifying the fittings
We proposed bespoke fittings that addressed the weaknesses in the original arrangement and revised how loads were transferred through the mounting assembly. The new fittings also had to work with the existing rudder and stock. We checked the revised design against the defined load cases and verified that it met the required factors of safety.
Once the design was finalised, we prepared the production drawings, coordinated manufacture and delivered the finished fittings to the client.
For yacht designers and boatbuilders, we can take responsibility for a specific engineering problem from the first investigation through to finished hardware. We work with your team to understand how the part fits into the wider design, develop and verify a proposal, and manage manufacture through to delivery.
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