Lever force F at a point "A" located by the coordinate vector r on the bar. The lever then exerts an output force F at the point "B" located by r. The rotation of the lever about the fulcrum "P" is defined by the rotation angle "θ" in radians. Let the coordinate vector of the point "P" that defines the fulcrum be r, and introduce the lengths which are the distances from the fulcrum to the input point "A" and to the output point "B", respectively. Now introduce the unit vectors e and e from the fulcrum to the point "A"
Darcy Lever railway station Darcy Lever railway station Darcy Lever railway station served the Darcy Lever area of eastern Bolton between 1848 and 1951. The station opened on 20 November 1848. It was on the Bury– section of the Liverpool & Bury Railway, which opened on the same day. To the east of the station, the valley of the River Tonge is crossed by Darcy Lever viaduct, which is high. It has eight spans supported by stone piers: two spans are long, and six are long. Each consists of six lattice girders: two , which also form the parapets, flanking four which are deep.