What are cable ducts?
The buried conduits that carry AGL cable across the airfield. They are laid with the civil works, so the route, depth and spare ways have to be agreed before the trench closes.
Cable ducts are buried conduits, usually plastic or concrete-encased, that carry AGL cable along its route. Cable is pulled through them between handholes, pits and cans, and can be replaced or added to without breaking the surface.
They are a civil interface because they are laid in trench or duct bank with the pavement and drainage works. The route, depth, bedding, encasement, crossings and spare ways must be agreed with the civil team before the trench is closed, and each duct end must line up with its chamber entry.
Protected way for pulling and replacing cable, usually in a duct bank.
Cable laid straight in the ground, harder to replace and more exposed to damage.
Frequently Asked Questions
Q1What are cable ducts in airfield ground lighting?
Buried conduits, usually plastic or concrete-encased, that carry AGL cables along a route. They protect cable from damage and allow it to be pulled in, replaced or added to without digging up the surface.
Q2Why are cable ducts a civil interface?
They are laid in trench or duct bank with the civil works, often under pavement, roads and drainage. Route, depth, bedding, encasement, crossings and spare ways must be agreed with the civil team before the trench is closed.
Q3Why include spare ducts?
Spare ways let cable be added or replaced later without breaking pavement again. Their number and size depend on the project and the owner's future plans.
Q4How do ducts relate to handholes?
Ducts run between handholes, pits and cans. Handholes sit at direction changes, crossings and long pulls so cable can be pulled and joined, and each duct end must line up with its chamber entry.
Q5How should ducts be protected?
By correct depth, bedding and backfill, concrete encasement where required, and warning tape above. Where ducts cross pavement or drains, the civil design sets the crossing method.
Q6Where are the requirements defined?
FAA AC 150/5370-10 and AC 150/5345-42 cover related items, and ICAO Aerodrome Design Manual Part 5 covers electrical systems. Confirm against the current edition and project specifications.
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