CARGO-SAFE™ Ultrasonic Hatch Cover Tester


Overview of UT testing

CARGO-SAFE™   The choice of marine surveyors across the globe

The ingress of water through leaking hatch covers is a main cause of damage to cargo. It is in the interest of ship owners, managers and insurers to guarantee the cargo hold is watertight, as damaged cargo caused by water leaking through hatch covers often results in large claims against insurance companies and P&I clubs.

CARGO-SAFE™ is an ABS Type Approved hatch cover tester. The CARGO-SAFE™ UT  tester provides a quick and simple method of establishing weather tightness of hatch covers, bow, stern and side doors, but unlike hose testing, has no negative side effects on the port or harbour environment and can be performed in sub-zero temperatures.

3 year Warranty and 5 year re-calibration interval *see Warranties under Support


The complete CARGO-SAFE™ hatch cover testing kit includes:

  • Ultrasonic Transmitter unit
  • Receiver unit
  • Protective IP66 storm-proof leather cases with neck and waist straps for hands free operation
  • Hard hat compatible headphonesCargo-Safe Data Kit
  • 2 Flexible inspection microphones (1 spare)
  • Telescopic microphone extension, up to 1.15m (45″)
  • Full operating instructions
  • Emergency microphone lead
  • Emitter, microphone and extension arm tester
  • Batteries and global charger (with 12V car adaptor)
  • 12-24V auxiliary power input lead
  • 450 x 320 x 100mm (17.7″ x 12.6″ x 3.9″) foam-lined black polymer carry case


CARGO-SAFE™ Ultrasonic Hatch Cover Tester Applications

CARGO-SAFE Printer friendly information sheet


A guide to conducting a hatch cover survey using a CARGO-SAFE

CARGO-SAFE™ Ultrasonic Hatch Cover Tester Applications

To test the tightness and water integrity of

  • cargo hatch covers
  • bow and stern doors
  • access hatch seals
  • Watertight doors
  • Weathertight doors

Unlike hose testing, ultrasonic hatch cover testing:

  • is compliant with port and harbour environment management plans as it does not pollute the marine environment
  • can locate holes and tears in hatch seals with pinpoint accuracy
  • causes no damage to cargo
  • can be conducted in sub-zero temperatures
  • can be carried out with the cargo in place
  • does not interfere with other crew activities.

Other CARGO-SAFE™ features

• Each CARGO-SAFE™ ultrasonic hatch leak detector comes with its own certificate of calibration and conformity.
• No training needed to operate – full instructions given.
• Simple to use, fast and accurate results.
• Switchable between dB (decibels) and percentage of OHV (Open Hatch Value).
• Does not need frequent periodic recalibration.
• Suitable to be carried as hand luggage on aircraft.
• The most powerful ultrasonic hatch tester available on the market with a 157 dB transmitter ­ suitable for any size of ship.
• 3 year warranty on Receiver and Transmitter.
• Durable and storm proof, environmental protection to IP66.
• LCD display allows ease of reading in bright sunshine or in darkness.
• LED and sound warning of low battery on the Transmitter.
• Direct access to free technical support for the life of the product.

CARGO-SAFE™ Calibration and Maintenance

The CARGO-SAFE™ ultrasonic hatch leak detection system is sold with a device that can be used to check the emitters, the inspection microphones, the extension arm and microphone emergency lead (The EMEA Tester). It is recommended that this is done before each survey, to ensure accurate results.  The CARGO-SAFE™ hatch leak detector is calibrated at the factory and is predicted to stay in calibration for 5 years. The constant output circuitry guarantees the ultrasonic output of the Transmitter is constant over the entire discharge cycle of the batteries, validated by the green flashing LEDs.

CARGO-SAFE™ Certificates and ABS Type Approval Compliance

Each CARGO-SAFE™ unit is sold with a certificate of calibration and conformity, giving full details of serial numbers and warranty periods. This certificate is evidence of each unit’s calibration and ABS Type Approval compliance.  The CARGO-SAFE™ hatch cover tester complies with the IACS UR Z.17 Directive. The certificate of origin confirms that CARGO-SAFE™ is manufactured in the United Kingdom.

CARGO-SAFE™ After Sales Technical Support

Class Instrumentation Limited guarantees the CARGO-SAFE™ ultrasonic hatch cover tester to be free from defects in materials and workmanship for a period of three years from the date of dispatch for the Receiver & Transmitter units and six months for the accessories. Free telephone and email technical support are available throughout the life of the product.

CARGO-SAFE™ is a lightweight ultrasonic system for testing the water tightness of cargo hatch covers. The complete system is contained in one carry case for convenient transportation.
Shipping Weight: 4kg (8.8lb)
Operational Weight: 2.4kg (5.3lb)

Transmittercargo safe transmitter

  • Weight: 475g (1.05lb)
  • Dimensions: 190 x 100 x 60mm (max) (7.5″ x 3.9″ x 2.4″)
  • Output: 157 dB @ 40KHz
  • Radio control standby saves battery life when not in use
  • Power Supply: 6 x AA rechargeable or alkaline batteries
  • Battery Life:  4.5 hours of operation
  • Storm proof leather case to IP66, designed to protect if dropped
  • Neck strap for hands-free use


  • Weight: 350g (12.3oz)
  • Dimensions: 160 x 100 x 30mm (6.3″ x 3.9″ x 1.2″)cargo safe receiver
  • Power Supply: 1 x 9v PP3 rechargeable or alkaline battery
  • Battery Life: 40 hours nominal with a PP3 alkaline battery
  • Switchable between dB and percentage of Open Hatch Value (OHV)
  • Internal loudspeaker ­ can be used instead of headphones
  • Internal microphone – can be used in the event of mic loss
  • Storm proof leather case – IP66, designed to protect if dropped
  • MAX HOLD capability to record the maximum reading
  • Backlight button with ON/OFF or auto OFF after 30 seconds
  • Neck and waist straps for hands-free use
  • Radio control button to switch the transmitter from standby to ON


Microphonecargo microphone

  • Weight: 110g (3.9oz)
  • Dimensions: 330 x 10mm diameter (13″ x 0.4″)
  • Bright yellow to aid visibility


cargo safe headphonesHeadphones

  • Weight: 50g (1.7oz)
  • 3.5mm stereo jack plug
  • Hard hat compatible



Emitter, Microphone and Extension Arm Tester

  • emitterWeight: 17g (0.6oz)
  • Dimensions: 46 x 31 x 20mm (1.8″ x 1.2″ x 0.8″)
  • Used to check the performance of the emitters, microphone, and
    extension arm of the CARGO-SAFE™  before a survey


Extension Armextension arm

  • Weight: 150g (5.3oz)
  • Dimensions: 390 x 40 x 30mm (15.4″ x 1.8″ x 1.2″)
  • Extended: 1150 x 40 x 30mm (45.3″ x 1.8″ x 1.2″)
  • Wrist strap for hands free use


Spare Microphone and Emergency Leadspare microphone

  • To be used in the event of either the microphone
    or extension arm loss


Battery Charger and Batteriesbattery cargo

  • 12 x rechargeable AA batteries
  • 2 x PP3 9v batteries
  • Global battery charger with car adaptor


Emergency Power Leadpower lead

  • Offers emergency power to the Transmitter in the event of a failed battery
  • Can accept an external power supply of 9 to 24 volts DC

How the CARGO-SAFE™ Ultrasonic Hatch Cover Tester Works

The principle for ultrasonic hatch cover testing is very simple. After the hatch covers are closed, a transmitter generating an ultrasonic signal is placed in the cargo hold (empty or loaded with cargo) emitting ultrasonic waves. The surveyor or operator then uses the CARGO-SAFE™ ultrasonic receiver to ‘listen’ from the outside of the hold and detect any ultrasonic sounds that pass through holes in the hatch cover sealing system with pin-point accuracy. The size of the leak can be established from the strength of the signal detected.

The CARGO-SAFE™ hatch cover leak detection system has three levels of emitters: upper, lower and vertical. This means that all the ultrasound is directed to the hatch covers, optimising its effectiveness. The diagram shows the dispersion pattern of the ultrasonic sound emanating from the CARGO-SAFE™ Transmitter. The high sound pressure level is ample to fill the largest of holds enabling reliable and accurate readings.

survey steps

Step by Step Guide to a Survey

1. The CARGO-SAFE™ Transmitter is placed in the cargo.

2. On the deck, with the hatches closed, the microphone and headphones are plugged into the Receiver.

3. The surveyor begins to inspect the hatch, holding the microphone against the hatch seals. Any gaps through which air or water can pass will allow the ultrasonic signal to pass and can be detected.

4. The display on the Receiver shows the decibel level of any ultrasound leaking through the hatch seals. It can also be heard through the headphones.

5. The flexible microphone and the extension arm allow the position of any potential leaks to be identified with pin-point accuracy. The size of the problem is established by the strength of the signal detected.

American Bureau of Shipping (ABS) Manufacturing Assessment Certificate Number 16-LD3207821
Cargo-Safe ABS Product Type Approval Certificate Number 20-1966580-PDA
ISO 9001:2015 Certificate Number 14124458
NCAGE Number U0B22
NATO Number 6635-99-958-4633
IIMS Corporate Membership Number C508

en_GBEnglish (UK)