David Nelson's Web Site






The Ship

The Canadian government Ship (CGS) Concretia was built in Montreal by Montreal Ship Builders Ltd. in 1917 for use as a buoy tender and lighthouse supply ship on the St Lawrence and the Eastern portion of Lake Ontario.  She was operated by a crew of 14.  Due to the lack of steel at the time she was build of  ferro-cement which is a mixture of cement and sand applied over a frame of rebar and wire mesh.  The hull was 132 feet long overall, 126 feet long at the waterline, a 22.2 foot beam and was 10.1 feet deep  The hull was 24  inches thick at the keel and 18 inches on the sides.

The Concretia operated as a lighthouse supply and buoy tender from 1917 to 1931 then sat idle until 1937.  For a period of time the empty hull was scuttled in Kingston harbour where it was used a wharf then in 1979 she was raised and converted to a private three masted barquentine and renamed Onaygorah.


The Model

One of the challenges in building a model of the Concretia was the lack of information about her.  All I was able to find were three photographs, her dimensions and a bit of historic text.

This photo gave me the shape of the hull, hawse holes for the anchor chain and openings in the hull for ropes to be passed through.


This photo was used for design of the superstructure, cranes and other fittings.


This photo is of the hull after it was raised from the bottom of the Kingston harbour.  It gave me another view of the hull and I used the height of the people standing on her deck to confirm the amount of the hull that was above the waterline.


Construction of the model

The hull of the model was built using bread-and-butter construction.  Layers of soft pine were pinned and glued together then carved into the hull's shape.  The top layer was recessed in from the hull's side to provide a solid base onto which the gunwales were glued after being steamed and shaped.  Hawse holes, scuppers and other openings in the hull were drilled and lined with brass tubing to provide a consistent, clean opening.

Hull, side profile.


The bow.


The stern.


Two views of the anchor windless, on the left, and the stern windless on the right.  The bevelled gears are there to connect with steam cylinders under the deck and are the drive mechanism for each windless. 

The parts of the anchor windless, from the center, are:  drive gears, cogged drums to pull in the anchor chain, levers to engage clutches. drum to pull in lines, clutch levers, and gypsy drums on the outside of the frames.  The stern windless has drums to pull in lines and a clutch on each one.  There is a guide pulley in front of each drum on this windless to route lines coming in from the side.


May 9, 2015


The model is very near completion at this point.  Items that remain to be done are:  Locks to secure the anchor chain, hatch cover, cleats, bollards on the deck.




Bow view showing anchors.

Forward windless.




Close up of crane base and it's windless.


Wheelhouse.  Compass and wheel are visible through the windows.


View of the cabins, davits and ship's boat.



Smoke stack and air intake.



Stern windless.


Stern of the model showing the propeller and rudder.


May 29, 2015

Foredeck now with cleats, bollard and anchor chain locks



Main deck with buoys on board for repair.


Close up of buoy.


Aft deck with bollards and cleats in place and flag.