(under subclass 235) Water tube boilers having water tubes extending over the bridge wall and a plurality of fireboxes, the products of combustion from one firebox meeting those from the other firebox and the fuel grate of at least one firebox being of the water grate type. The firebox with the water grate is generally located above the other firebox and the draft is down through the water grate.
SEE OR SEARCH THIS CLASS, SUBCLASS:
67, and 204, for other types of boilers having intermediate draft water grates.
