The tool you're likely thinking of is called a conduit brush or conduit swab. There are variations on the design including: Wire brush

A metal brush with stiff wires to scrub the inside of the conduit.

Nylon brush

A more gentle option for conduits where you want to avoid scratching the interior surface.

Swab

A tool with foam or rags attached to a flexible rod or chain to wipe out debris.Given your situation with decades-old underground conduits, especially those under a lock structure, you absolutely should raise an issue. Here's a breakdown of why and what to recommend:

Why it's critical to raise an issue



Insulation Damage

Rust, scale, sharp edges, and accumulated debris inside old conduits can severely damage the insulation of the 300 kcmil conductors during the pull. This could lead to:

Premature insulation failure

The conductors might initially pass testing, but the compromised insulation will degrade over time, leading to shorts, ground faults, and potential fire hazards.

Difficult Pull

Rough surfaces will significantly increase the pulling tension and friction, potentially exceeding the conductor's pulling strength and damaging the conductors as the conductors are pulled through the conduit.

Accessibility and Repair Costs

Since the conduits are under the foundation of a lock, repairs would be incredibly difficult and expensive. A conductor failure would necessitate excavation, potentially disrupting lock operations, and incurring very high costs.

Safety

Electrical failures can create serious safety risks for personnel and equipment.

Code Compliance

NEC (National Electrical Code) Article 300.4(G) addresses protection against damage. While not explicitly stating cleaning of existing conduit, the intent is to ensure conductors are properly protected. Using obviously degraded or obstructed conduit would be a code violation.

Long-Term Reliability

The entire purpose of a proper electrical installation is long-term reliability. Neglecting the condition of the conduit before pulling conductors jeopardizes that goal.

Recommendations to include in your issue


Conduit Inspection and Cleaning

Require the contractor to inspect and clean the existing conduits before conductor installation. The contractor should do the following:

Video Inspection

A video inspection is highly recommended. This will allow you to view the inside of the conduits and determine the extent of the corrosion and debris.

Mandatory Cleaning

Specify that the conduits must be thoroughly cleaned using appropriate methods, which should include (but not be limited to): Using a conduit brush or swab. Applying a rust inhibitor or cleaner (if appropriate for the conduit material). Flushing the conduit with water (if possible and appropriate) after cleaning to remove residual debris.

Re-Inspection

After cleaning, the contractor should reinspect the conduits to verify that the interior surfaces are smooth and free of sharp edges or obstructions. If the corrosion and debris are such that they cannot be removed using these methods, the contractor must notify the engineer to discuss options, which will include the replacement of the conduit.2.

Conduit Lubricant

Specify the use of a high-quality conduit lubricant specifically designed for pulling large conductors. This will reduce friction and the risk of insulation damage during the pull.3.

Pulling Tension Monitoring

Require the contractor to monitor pulling tension during the conductor installation. Exceeding the conductor's maximum pulling tension is a clear indication that something is wrong, and the pull should be stopped immediately.4.

Post-Installation Testing

After the conductors are pulled, specify insulation resistance testing (megger test) to verify that the insulation has not been damaged during installation.5.

Documentation

Require the contractor to document all inspection, cleaning, and testing procedures. This documentation should include photos or videos of the conduit before and after cleaning, as well as records of pulling tension and insulation resistance measurements.

How to Raise the Issue



Formal Written Communication

Submit a formal RFI (Request for Information) or a written comment on the design package. This creates a record of your concerns and ensures that the issue is properly addressed.

Reference Relevant Standards

If possible, reference relevant sections of the NEC, or any applicable local codes or standards that address conductor protection and installation.*

Emphasize the Risks: Clearly state the potential consequences of not addressing the condition of the conduits, including the increased risk of insulation damage, premature failure, and high repair costs.By raising this issue and specifying the necessary steps, you can help ensure a safe, reliable, and long-lasting electrical installation. Flag for review