extension ladder

Thân thiện

A firefighter uses an extension ladder to reach a high window.

Definition

Noun: A portable ladder consisting of two or more sections that slide or telescope within one another, allowing its total length to be adjusted and extended for reaching higher elevations. It is designed to be compact for storage and transport while providing variable working height.

Usage

An extension ladder is used when a fixed-length ladder is insufficient to safely reach the required height. The user extends the sections (typically called the fly section(s) and the base section) and locks them into place using a mechanical locking device (like rung locks or pawls) before climbing.

Examples

• Firefighters quickly raised the extension ladder to reach the third-floor window.
• For cleaning the gutters, you will need a sturdy extension ladder that can safely reach the roof's edge.
• Always ensure the locks are fully engaged on an extension ladder before you begin to climb.

Advanced Usage

• Professional Context: In construction and maintenance, an extension ladder is essential equipment. Proper setup involves following the "4-to-1 rule": for every four feet of ladder height, the base should be one foot away from the wall or supporting structure.
• Safety Protocols: A common instruction is to "foot" the ladder, meaning a second person steadies the base while another person is ascending, descending, or working from it.

Variants and Related Words

• Step Ladder (n): A self-supporting portable ladder with a hinged design and a platform, not designed for extension.
• Telescoping Ladder (n): A subtype of extension ladder where the sections slide smoothly within each other, often using a collapsible design.
• Rung Lock (n): The specific locking mechanism on an extension ladder that secures the extended section in place.

Synonyms

• Telescopic Ladder
• Extendable Ladder

Related Phrases

• To extend a ladder: The action of pulling the fly section(s) upward to increase the ladder's length.
• To retract a ladder: The action of lowering the fly section(s) to decrease the ladder's length for storage or transport.

Học thuật

Noun

1. a ladder whose length can be extended