Document ID: chunk:federal_register_of_legislation:F2020L01547:reg:2022:p11
Version: federal_register_of_legislation:F2020L01547
Segment Type: reg
Provision Reference: reg 2022 (pt 11/15)
Character Range: 156508–159333

Pattern of flashes of light emitted by a lighthouse,
 designed to identify that particular lighthouse.

Copper
 A red malleable metal of low resistivity.

 E

Entrance vestibule
 Enclosed passage or room between the outer door and the interior of the building.

External catwalk
 Landing around the external face of the tower complete with hand rail. Montague Island's is 1880 Chance Bros. cast iron lattice.

 G

Glazing
 Middle section of the lantern, circular or polygonal   in plan, between the lantern roof above and the lantern base below, made up of glass panes held in a framework of glazing bars and astragals.

 I

Intermediate floors
 Levels found mid-way up a building.  Montague
 Island has two intermediate floors of iron plate.

Internal catwalk
 Open landing inside the tower complete with

 handrail. Montague Island's original internal catwalk was removed and replaced with sheet flooring supported on the original openwork cast iron brackets.

Iron
 There were two common types of iron used in lighthouse construction: wrought and cast. Older lights will almost certainly contain these iron types. Wrought iron has been worked by hand and is an iron alloy with a very low carbon content in contrast to steel, it also has fibrous inclusions. Cast iron is iron which has been heated until it liquefies, and is then poured into a mould to solidify.

 L

Lantern
 The glazed enclosure, usually of cylindrical or polygonal shape, at the top of a lighthouse, which surrounds and protects the optical apparatus. It contains the optical apparatus, made up of the lantern roof, lantern glazing and lantern base sections.

Lantern floor
 The level in a lighthouse at which the lantern is installed, and by which access may be gained to the optical system and to the inside and outside of the lantern glazing. The lantern floor is generally at or near the same level as the catwalk and can be made from steel, concrete, or timber.

Lantern glazing
 The middle section of the lantern,  circular  or polygonal in plan, between the lantern  roof  above and the lantern base below, made up of glass panes held in a framework of glazing bars. On the landward side there may be blank panels in place of glass, or other opaque construction. Types of lantern glazing include: flat and curved trapezoidal panes and curved diamond/triangular panes. Montague Island  uses three tiers of flat trapezoidal glass.

Lantern roof
 Roof of the lantern. Usually made of copper sheeting over a framework of rafters. Montague Island houses an 1880 Chance Bros. part spherical dome.

Lens
 Assembly transparent optically refracting element of glass. The surface is usually spherical in form.

Light source
 Electric bulbs and LEDs now illuminate most
 lighthouses.

Lighthouse
 The principal structure of a lightstation, generally