flanging, however, is done usually by hand, the plates being heated and hammered down over shaped blocks with wooden mallets. The firehole, the circumference of which has to be flanged outwards to join the doorplate of the firebox shell, is however dished in a hydraulic press. (In Fig. 2 the older form of firehole ring is used instead of the flanged construction.) The flanges are then cut level by placing the plates on the table of a large horizontal band saw, and setting them level for the saw to cut off the ragged edges and leave the flanges of the correct width.
The holes for the tubes in the copper firebox tubeplate, and also in the steel smokebox tubeplate, are marked off either by drawing them out in detail on the plates when an isolated engine is being made, or by marking their positions from a template when several engines are being built.
The firebox plates are fitted to the foundation ring, and are put together in a similar manner to those of the firebox shell. Rivets of very soft iron or steel are generally used for copper fireboxes, though copper rivets have been used in this country and are still used on some French railways. The riveting is done with a hydraulic riveter having a very long gap or jaws, but the pressure used on copper plates is considerably less than that used on the steel plates of the boiler. If the roof stays are of the girder or bar pattern (as at O, Fig. 2), they have to be marked off and fitted to the firebox before the
