Other Placement Methods

Purpose

Pick the right placement method when directional boring is not the best fit, and run it with the controls that keep the duct protected and the crew safe. Open trench, plowing and micro-trenching each have a place. Crews often place several ducts in one run: in one plow pass where the design and the plow maker allow it, or side by side in a trench per the design. Each method also has its own way to fail: trench cave-ins, plowing through an unpotholed crossing, or a micro-trench the city will not accept.

When to Do It

• Trigger: the design or field conditions call for a method other than boring on a segment.
• Prerequisites: the permit allows the method on that segment (UG-01), a valid locate ticket (UG-03), and crossings potholed (UG-04).
• Previous step: UG-07 Reaming and Pullback.
• Next step: UG-09 Handholes, Vaults and Pedestals.

Roles

• Design engineer: chooses the method per segment and confirms the permit allows it.
• Foreman: runs the work and checks cover, backfill and restoration against the permit.
• Equipment operator: runs the trencher, plow or saw.
• Competent person: inspects trenches and protective systems, as OSHA Subpart P requires.
• Laborers: place bedding, duct, warning tape and backfill.

Equipment and Materials

• Trencher or excavator for open trench.
• Vibratory or static plow for long rural runs, with a blade and feed for the duct count per the plow manufacturer.
• Micro-trenching saw with water or vacuum dust control for pavement.
• Trench protective system: sloping, shoring or a shield.
• Compaction equipment for backfill in lifts.
• Warning tape, bedding and backfill per spec.
• Microduct and fill or sealant for micro-trenching, per the municipality.

Safety

Procedure

Method Comparison

Typical uses only; the design engineer chooses the method, and the permit must allow it.

Method	Typical Use	Key Controls	Main Risks
Open trench	Short runs, many crossings, duct banks, or where boring is not practical	Cover per permit; bedding and backfill per spec; ducts arranged and spaced per design; warning tape at the specified depth above the duct; compaction in lifts; OSHA excavation rules for trenches	Cave-in; settling backfill; damage to crossing utilities
Vibratory or static plow	Long rural runs in suitable soil	Pothole crossings first; plow depth per permit; duct count per design and plow maker; avoid rocky ground	Unseen crossings; duct damage in rock
Micro-trenching	Pavement routes for microduct where the municipality allows it	Depth, fill and sealing per municipality; restoration quality	Shallow utilities in the pavement; silica dust; rejected restoration

Hold Points

Records to Keep

• Method used on each segment.
• Depth of cover with stationing or GPS.
• Duct count and size for each run.
• Photos of open trench before backfill, with a measuring rod in view.
• Compaction or density test results where required.
• Trench inspection records from the competent person.
• Damage reports and owner notifications for any facility damaged, however minor.

Common Mistakes

• Plowing through unpotholed crossings. The plow finds the gas line before you do.
• Backfilling in one lift. It settles, and the restoration fails.
• Forgetting the warning tape or placing it at the wrong depth.
• No silica controls on the saw. Dry cutting exposes the crew and can stop the job.
• Poor micro-trench restoration. The municipality’s acceptance depends on it.

Standards and References

• 29 CFR 1926 Subpart P: trenches and protective systems.
• 29 CFR 1926.1153: respirable crystalline silica in construction.
• MUTCD Part 6: temporary traffic control.
• CGA Best Practices: excavation practices.
• 49 CFR Part 196: excavation near gas and hazardous liquid pipelines, including reporting any pipeline damage to the operator and calling 911 on a release.
• State one-call law: tickets and tolerance zones before any mechanized digging.
• Municipal micro-trenching details and permit conditions.
• Plow manufacturer instructions.
• Plastics Pipe Institute (PPI): Handbook of PE Pipe, Ch. 14 (Duct and Conduit), trenching and direct plow placement.

On the Map

• Micro-Trench: narrow saw-cut trench in pavement for microduct.
• Warning Tape: marking tape buried above the duct in open trenches.
• Duct Bank: several ducts placed together, sometimes encased.
• HDPE Conduit: the duct placed by any of these methods.

Related Tools

Not applicable: no FAHMY tool covers method selection.