David Nelson's Web Site
Steam Ferry Trillium
The Trillium is a very unique and historic ferry that was built in Toronto in 1910 by Polson Iron Works and used to carry passengers between the city of Toronto and the Toronto Islands. She was decommissioned in 1957 then restored to operating condition in 1974. Today she continues to operate as part of the Toronto ferry fleet and usually runs on weekends when passenger volumes are high.
The Trillium is 150 feet long, has a molded breadth of 30 feet, an extreme breadth of 47 feet and depth of 8 feet. She was designed to carry 1450 passengers. This was reduced to 955 later. She was powered by a double compound steam engine which had a stroke of 48", the high pressure cylinder had a 17.5" bore and the low pressure cylinder a bore of 34".
December 22, 2019
The model will be built at a scale of 1:48 which will give it dimensions of 37.25" long, 11.5" wide at it's extreme and 2" deep. The engine will have a stroke of 1.25", the bore of the high pressure cylinder will be 0.36" and the low pressure cylinder 0.71". My plan is the have the engine operate on compressed air using the same valves and links as is used on the full size vessel.
I considered the paddle wheels to be the most complex and demanding part of the model so decided to start there. This took three months to complete.
These paddle wheels are feathered which means the paddle boards do not follow the curvature of the wheel. They are near vertical when they enter the water then pivot so that they are vertical as they travel through the water. The round arms you see on the facing side of the wheel pictured above are what causes the boards to pivot back and forth.
To make all of this happen it required 98 pieces of metal, 8 paddle boards, 128 0.040" diameter bolts with nuts and 230 0.022" diameter rivets on each of the wheels.
July 9, 2020
Since completing the paddle wheel My focus has been on the cylinders, the crank shaft and their support beams.
Profile view of the cylinders, support beams and crank shaft.
The cylinders are turned from brass rod and lined with
cast iron sleeves. Pistons are turned in
View of the cylinders, support beams and crankshaft looking aft.
This is a compound engine. High pressure steam
from the boiler enters
December 7, 2020
Here we see the reversing gear. When the
reversing gear is in it's lower position, as seen here, the eccentric arm,
If the reversing gear of moved up it will be driven by
the lower eccentric arm which is 180 degrees out of phase
The position of the reversing gear is controlled by a lever on the operators platform.
There are 40 benches on the Trillium for passengers to
sit on during the crossing. For the model I had a friend
The two pipes facing you are the exhaust tubes.
They will be vented down through the ferry's hull into the
The pipe on the right, partially hidden by the exhaust
tube, is the input of high pressure air to the cylinders.
The ladder laying on the deck will, when installed, provide crew access to and from the hold and this deck.
The stained wood ramps on each side of the crank shaft provide safe passage for passengers over the drive shaft.
These levers are used by the ferry's engineer to control the engines. Their functions from left to right are:
Profile of the main deck of the model. All of the windows are glazed with acrylic.
Here we see the bow which is identical to the stern so
the ferry can go back and forth to the islands without
This is the operators area. The levers control
the the flow of steam and the engines. The dials to the right of
These stairs provide passenger access between the main
and middle decks. The benches shown here are not
A broader view of the operator's area.
View of the pressure and vacuum gauges used by the operator to monitor the status of the system.
The links below will take you to videos of the engines
and paddle wheels running. Once they stop you can
The brass units running parallel to the piston rods are
part of the Stevenson Reversing Gear which, controlled
The paddle wheels are feathered which means the paddle
boards will be near vertical when they enter the