The futtocks are fastened to the side of the upper keel timber with 1 inch diameter iron bolts. At least two bolts are used per futtock. Although it was not possible to make an exact measurement of the angle at which the futtocks are attached to the keel, it is fairly acute. Where it could be measured, this planking was between 8 inches and 10 inches in width and 4 inches thick. Photographs of the Niagara show the hull planking up to the preserved cap rail to be significantly heavier than that used above it.
Photographs also show a heavy wale at the level of the lower deck.
At the places where it could be felt, the garboard strake appears to have been nailed to the keel near the joint between the two keel timbers. No rabbet was noted on the keel and the garboard was probably bevelled to fit flush against it. The Niagara's ceiling is as heavy as the outer hull planking. The measured widths of ceiling planks averaged around 8 inches. A few as narrow as 4 inches were present as were a number of stealers towards the bow.