Lightweight fatigue resistant railcar truck sideframe with tapering I-beam construction

An improved railcar truck sideframe of relatively light weight and open construction for carrying a railcar payload, said sideframe having a longitudinal axis, a front end, a back end and a midsection therebetween, comprising:

• a longitudinally elongate solid upper compression member having a first end and a second end, each of said ends including a downwardly projecting pedestal jaw depending therefrom;
• a longitudinally elongate solid lower tension member having a front section, a back section and a central section therebetween, said central section generally parallel to said upper compression member, said front section comprising an upwardly extending solid diagonal section and defining a first bend point, said back section comprising an upwardly extending solid diagonal section and defining a second bend point, each of said diagonal sections extending to and connecting with said respective upper compression member ends at a respective pedestal jaw;
• a substantially solid vertical web having a pair of sides, said web including an open portion at said sideframe midsection which defines a front vertical column and a rear vertical column and a bolster opening therebetween;
• wherein said entire sideframe is of a generally solid, I-beam cross-sectional shape, said I-beam cross-sectional shape defined by a solid, horizontally disposed top flange corresponding to said solid upper compression member, a solid, horizontally disposed bottom flange corresponding to said solid lower tension member, and said substantially solid vertical web interconnecting said upper flange to said lower flange such that an open, I-beam shaped, lightweight sideframe is formed, said top flange, said bottom flange, and said vertical web each having a constant cross sectional thickness between said front and rear vertical columns and a continuously tapering cross sectional thickness from a respective said vertical column to a respective said pedestal jaw, said cross sectional thickness of said vertical web and said bottom flange substantially equal, and said cross sectional thickness of said top flange relatively smaller than said cross sectional thickness of said bottom flange,
• said top and bottom flanges each having a respective dimensional width of substantially equal extent, wherein said width of each said flange is constant between said front and rear vertical columns and continuously tapers from a respective said vertical column to a respective said vertical jaw, said top and bottom flange width between said vertical columns about twice the width as at said pedestal jaws,
• said top and bottom flanges also including simple radii curves of fillet material where said respective flange joins said vertical web, said vertical web also includes simple radii curves of fillet material where each respective said vertical column joins said vertical web, said sideframe further including means for reinforcing said vertical web in order to prevent twisting of said web, said reinforcing means vertically attached to each said side of said web at each said pedestal jaw and between said first and second bend points,
• said vertical web including at least two spaced lightener openings, one of said openings longitudinally disposed an extent forward of said bolster opening and the other of said openings disposed a substantially equal longitudinal extent rearward of said bolster opening.