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The Boat

Tom Adams Boatbuilder

Our current project is the restoration of Miss Canada IV. 
It is not often you get the privilege to work on such a famous historic race boat.

Miss Canada IV in Ingersoll.

Tom & MC IV with her deteriorated frames.

Hull and frame removal.

The aluminium box. 


The rudder and trunnion bearing which held the end of the propeller shaft.  

Miss Canada IV (MCIV) is an iconic late 1940’s Unlimited class race boat whose estimated top speed was over 200 MPH, eclipsing the then current official world speed record of 160 MPH.  This boat, originally owned and driven by Harold & Lorna Wilson, was powered by a 3,000 HP Rolls Royce Griffon engine, the largest aero engine in the world at that time.  It was still on the British secrets list when British authorities permitted the Wilson team to bring it to Canada to challenge the Americans for the coveted Harmsworth Trophy, emblematic of world supremacy in powerboat racing. 

MCIV is a 34 foot long mahogany beauty with an 10 foot beam.  The hull, revolutionary at the time, is a Doug Van Patten-designed two-step “keel knuckle” hydroplane.  MCIV was retired from racing in 1953 and by 2011 dry rot had set in, requiring a complete restoration before repowering her with a Rolls Royce engine.  We focused on the challenges of restoring and rebuilding MCIV while Jamie Smith, Restoration Project Manager searched for and procured a Griffon engine.

MCIV hull’s condition required us to completely replace all of her frames and bottom while preserving the original decks.  While this may sound straight forward, it is actually the reverse sequence employed when building a boat.  Normally a hull is framed, the running surfaces attached, the hull rolled over and then the decks are added.  Here the old frames and bottom first had to be carefully separated from the deck and engine stringers; then new frames, gunwales and bottom would be designed, constructed and then carefully rebuilt into the preserved deck.  

The next challenge faced was the two massive cracks that were discovered on both sides of the 2nd step of the hull.  We could see how Greavette Boats had retrofitted the hull framing to repair the cracks in 1950.  The solution was to take their ideas and incorporate them into the new framing.  Along with the use of better glues and building processes, this resulted in a stronger, more durable hull without altering the structural design.

Miss Canada IV had always been hard to steer.  The Van Patten design was so successful at releasing surface tension of the water that along with the thrust of the powerful Rolls Royce Griffon engine, MCIV’s transom lifted right out of the water and she rode on her propeller…a first.  This left only 4” of rudder in the water to steer with.  The restoration team decided the new rudder would be designed with an additional 8” added to its length.  However, this created another problem:  as the longer rudder would cause a massive torque increase on the transom due to the tremendous thrust from the propeller, our team realized the transom would now need to be much stronger. An extension of Van Patten’s  original thinking solved this problem; working from the original aluminum “knee” braces, a complete aluminum box was built and tied into the boat’s transom and frame. The boat and transom is now stronger than ever, and still consistent with the original design.   

By Mid-May of 2012 our team was busy completing the restoration of Miss Canada IV.  The Griffon engine along with rebuild team from Flight Engineering, the UK company chosen to supply and modify the engine and build its transmission, would be arriving in June.  Experts from Seattle’s Hydroplane and Race Boat Museum would also help engineer the installation of this powerful engine and her running gear. 

This project has given us an opportunity to work with the best talent in the world, a truly international team. 

More...Return to Muskoka

Read the remarkable story of Harold & Lorna Wilson who developed and raced Miss Canada IV.  The Story…