Document ID: chunk:federal_register_of_legislation:F2023L01286:reg:2028:p3
Version: federal_register_of_legislation:F2023L01286
Segment Type: reg
Provision Reference: reg 2028 (pt 3/9)
Character Range: 151444–154146

as 'near Birmingham'. The business was absorbed into the Pilkington group of companies in 1951 and now ceases to exist.

Character – pattern of flashes of light emitted by a lighthouse, designed to identify that particular lighthouse.

Copper – a red malleable metal of low resistivity.

E
External catwalk – a landing around the external face of the tower, usually complete with handrail. Gabo Island's external catwalk is comprised of 1888 Chance Bros. cast iron lattice floor panels with no handrail.
I
Intermediate Floors – levels found mid-way up a building. Gabo Island has 6 intermediate half-floors of original iron plate. Some portions made of recent steel chequer plate.

Internal – an open landing inside the tower complete with handrail. Gabo Island internal catwalk is comprised of 1888 Chance Bros. cast iron lattice floor panels.

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 cane be made from steel, concrete, or timber. Gabo Island's lantern floor is of iron plate.
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 & curved trapezoidal panes and curved diamond/triangular panes. Gabo Island's lantern glazing is of flat trapezoidal glass.
Lantern Roof – the roof of the lantern. Usually made of copper sheeting over a framework of rafters.
Lens Assembly – a transparent optically refracting element of glass. The surface is usually spherical in form.
Light Source – electric bulbs now illuminate most lighthouses.
Lighthouse – the principal structure of a lightstation, generally made up of a lantern, balcony