SUBC
The Beagle, SUBC's 2023 submarine
Overview
SUBC is UBC's human-powered submarine design team. Every two years the team designs and builds a submarine from scratch and races it internationally against other teams. The one hard rule is that nothing electric can drive the sub, so the pilot pedals it like an underwater bike and anything that wastes power between the pedals and the propeller slows the whole submarine down.
I was on the team from September 2023 to August 2025:
- Drivetrain and propulsion member, September 2023 to August 2024
- Propulsion lead and team captain, August 2024 to August 2025
My main contributions were:
- Replacing the chain drive with gears
- Helping design a toroidal propeller
- Building a jig to test propellers outside of the submarine
- Leading the propulsion team on the propeller for our 2024-2025 submarine, Mari
- Running the team as captain
Implementation
Drivetrain
Our chain drive kept skipping, so in my first year I replaced it with a gear drive.
Toroidal propeller
In my first year I helped design a toroidal propeller in SolidWorks. A toroidal propeller has blades that loop back onto themselves instead of ending in a tip, which cuts down on the vortices that come off the blade tips and waste power.
I ran flow simulations on the candidate designs so we could pick the best one. We then 3D printed it, since the looped blade shape would be extremely difficult to make any other way, and coated it in epoxy resin to seal and smooth the printed surface.
Flow simulation of one of the propeller designs
I also built a test jig so we could measure a propeller's performance on its own, instead of having to mount every new propeller in the submarine to try it.
Propulsion lead
As propulsion lead I ran a team of eight people designing the propeller for Mari and the mechanical supports that hold it and its duct onto the hull. We designed the propeller using SolidWorks and Ansys flow simulations, and printed each blade in PETG with half of the hub built in, so two blades bolt together around the shaft.
One of the 2024-2025 propeller blades
Team captain
I was also team captain over the same year, which meant managing a team of over 60 people and a budget of $40,000 while we designed and built Mari.
The SUBC team
