gCAT4+ Swing Warning Explained: Correcting Operator Errors
The "Swing" Problem: Correcting Operator Technique (gCAT4+)

The "Swing" Problem: Correcting Operator Technique (gCAT4+)

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← Part of the Series: Ultimate Guide to Cable Avoidance

The "Swing" Problem: Correcting Operator Technique with gC.A.T4+

The gC.A.T4+ is the first locator that "tells on you." Fleet managers across the UK are receiving C.A.T Manager reports showing thousands of "Swing Warnings."

Is the unit broken? No. Your technique is.
Swinging a C.A.T like a metal detector is the #1 cause of utility strikes on surveyed ground. Here is why, and how to fix it.

The Geometry of Failure

The C.A.T4 uses two internal coils (Top and Bottom) to calculate depth and position. These coils must be vertical to align with the vertical magnetic field of the cable.
The Error: When you swing the unit in an arc:

  • At the bottom of the arc (centre), the unit is vertical.
  • At the edges of the swing, the unit is tilted (often >30 degrees).

The Result: The tilted coil picks up the signal incorrectly. The locator thinks the cable is "moving." The depth reading becomes meaningless. The user fails to pinpoint the line.

The Fix: "Pendulum" vs "Windscreen Wiper"

Bad Technique (Windscreen Wiper): Locking your elbow and swinging your wrist. The unit tilts wildly.
Good Technique (The Pendulum): Keep your wrist rigid. Move your arm or walk side-to-side. The handle of the C.A.T should remain pointing at the sky, perpendicular to the ground, at all times.

Managing the Data

If your team has a high "Swing Count" on their logs:

  1. Don't Discipline immediately. Most users don't know they are doing it.
  2. Demonstrate the Distortion. Show them how the bar graph jumps when they tilt the unit over a known cable.
  3. Check the SWINGâ„¢ feature: Ensure the haptic vibration is turned on in the C.A.T4 settings so they feel the mistake in real-time.

Conclusion

The Swing Warning isn't a nuisance alarm; it's a precision tool. Eliminate the swing, and you eliminate the ghost signals.

Competence & Training: The Forgotten Variable

You can buy the most expensive equipment on the market, but if the operator is untrained, it is a paperweight. Health & Safety guidance HSG47 makes it clear: equipment must be used by competent people.

We recommend a tiered training approach:

  • Level 1 (Basic): Manufacturer-led familiarisation (turning it on, self-tests).
  • Level 2 (User): EUSR or CITB recognised courses for Genny usage and swing technique.
  • Level 3 (Manager): Data log analysis and permit-to-dig management.

Don't just tick the box ensure your team understands the physics behind the beep.

Field Tips from the Training Centre

The "Null" Method

While "Peak" mode is standard for tracing, "Null" mode is excellent for pinpointing. In Null, the signal drops to zero when you are directly over the cable. Use Peak to find it, and Null to verify it.

Induction Clamps

If you cannot get a direct connection to a live cable, use a Signal clamp. However, ensure the clamp acts like a "transformer" it must click shut completely around the cable. A 1mm air gap in the jaws decreases signal transfer by 50%.