A counterweight arbor is a sturdy mechanical assembly that serves as a carriage for counterweights. The standard crankshaft is cast iron with eight counterweights. V8s with crossplane crankshaft can be easily balanced with the use of counterweights only. His technique uses simple machines such as levers aided by counterweights and pivots. This arrangement also reduces the requirement for counterweights, reducing the mass of the crankshaft. FCW cranks have 2 counterweights on each crank throw. Examples include sailboat keels, as counterweights and as shielding in industrial radiography cameras. At that time, bascule bridges were built with expensive iron counterweights. Add-ons include handlebar weights, isolated foot pegs, and engine counterweights. Sometimes, however, crank-balanced units can become prohibitively heavy due to the need for counterweights. The counterweights, housed inside the two piers, weigh . It's also used by counterweights for lifting up an elevator, crane, or sash window. The loading bridge is used to add or remove counterweights from arbors. Counterweights and balances were also used to increase the lifting power of the apparatus. Meanwhile, a set of wedge-shaped counterweights weighing 3,700 pounds total was designed by Fisher.