The short tie beam (C), near the apex, serves as the member to receive the thrust and stress of the curved ribs (D, D). It forms a most graceful type of roof, and is capable of the most exquisite ornamentation, but it is used for the high pitched roofs only.
Fig. 291½. Hammer Beam Truss.
The acme of all constructions, in which strength, beauty, and capacity for ornamentation are blended, is the Hammer Beam Truss. Here the hammer beam projects inwardly farther than in the preceding figure, and has a deeper bracket (B), and this also extends down the pendant post (C) a greater distance.
The curved supporting arch (D), on each side, is not ribbed, as in the Rib and Collar Truss, but instead, is provided with openwork (not shown herein), together with beadings and moldings, and other ornamental characteristics, and some of the most beautiful architectural forms in existence are in this type of roof.
What are called Flying Buttresses (E) are sometimes used in connection with the Hammer Beam Truss, which, with heavy roofs and wide spans, is found to be absolutely necessary.