Chapter XCII: Section 106: Doors, Manholes and Covers

=1927. Application of a single crosshead and bolt= to close two covers, as in a pump clack-box.

=1928. Cone seated cover,= with hand-lifting crossbar and recess.

=1929. Crosshead and man- or mud-hole,= as commonly used for boilers, &c.

=1930. Cast-iron manhole and block;= ~T~-head bolts are generally used, but also eye-bolts, as in No. 937.

=1931. Wrought-iron plate lid,= or cover for a tank.

=1932. Wrought-iron dished cover,= with hinged crossbar and ~T~-screw used largely for gas retorts.

=1933. Furnace door;= hinged, with inside plate to protect the door from the heat.

=1934. Manhole door with water seal,= or packed recess to keep back gases, smell, &c.

=1935. Screwed plug handhole.=

=1936. Wrought-iron boiler manhole cover, and block,= a special manufacture.

=1937. Type of sliding door;= can be made airtight by planing the seatings.

Hinged doors are well-known. For hinging, see Section 50. For
fastenings, see Locking Devices, Section 49.

See also Nos. 931, 937, 940, 962.