Frame components are rigid cast gray iron frame, heavily ribbed and reinforced with integrally cast crosshead extensions; open frame top construction with steel tie rods, cast iron spacers and an individual cover over each section; forged alloy steel crankshaft with passages for pressure lubrication, counterweighted
to reduce horizontal moments; and forged allow steel connecting rods, rifle-drilled for pressure lubrication.
In the current paper two articles were used, both very thorough but unpublished and available only on the Internet: Trebuchet Mechanics by Donald Siano and The Counterweighted
Trebuchet--an Excellent Example of Applied Retromechanics by W.
Other features include counterweighted
flappers, elastomer throat gaskets, stainless-steel pellet deflectors, and lid-mounted sequence valves.
binocular bar allows a range of vertical motion, from just above the horizon to directly overhead.
The stairway is held within the form of a double ellipse and, counterweighted
, is suspended from the cat's cradle of steel cabling which supports a new and extended glass roof.