Abstract: A lifting mechanism having a base at least one upright mounted on the base and a pair of support arms mounted for vertical movement along the upright. A jack is provided for lifting and holding the support arms. The jack is supported on a stand which can be supported at various selected positions along the length of the upright.

Abstract: A railroad car roof panel and skylight assembly. The assembly includes a rectangular metal roof panel. A pair of corrugations are formed in the roof panel with the corrugations extending longitudinally of the roof panel and spaced apart from one another transversely across the roof panel. A pair of light holes are formed in the roof panel between the corrugations. The light holes are positioned longitudinally of each other with each of the light holes having an inner edge. A translucent plastic window is located above each light hole. Each transparent window has a shape similar to but larger than the shape of its light hole and is positioned to overlie the inner edge of its light hole. The transparent plastic window may be planar or dome shaped. A ring shaped gasket formed of an elastomer such as EPDM has an annulus of rectangular transverse cross section with a thickness greater than that of the translucent window. The gasket also has an integrally outwardly extending brim which is thinner than the annulus.