What an EFNARC Nozzle Operator Certificate Verifies
Specifications on tunnelling and mining projects ask for EFNARC certified nozzle operators. EFNARC runs the sprayed concrete industry's own nozzle operator certification scheme. It is the only globally recognised certification scheme that covers both Hand Spraying and Robotic Spraying of sprayed concrete, and it certifies the two as separate categories. The Hand Spraying certificate is the only hand spraying nozzle operator certification available in Australia. The assessment is carried out by a Certified EFNARC Examiner and the certificate is issued by EFNARC. It is valid for 5 years.
Theory and Examination
One day in the classroom covers the concrete, admixtures and accelerators, the equipment, the spraying method, thickness control, rebound, the EFNARC quality requirements and the safety controls at the face. The candidate then sits the EFNARC online examination, drawn from EFNARC's question database.
A nozzleman who understands why the accelerator dose is worked on the total binder, or what a higher slump does at the nozzle, can recognise a problem at the face and report it before a wall is sprayed with it.
Verified Experience
The scheme asks for 40 days of documented spraying before the final practical assessment. The days are recorded on the EFNARC work experience form and signed by a supervisor, shift boss, project manager or another responsible person who saw the work. The form records the project, the site, the dates, the equipment and the number of days, with the name, position and contact details of the person signing.
We contact the signatory and ask for photographs of the operator spraying on that site where they exist. Experience that cannot be confirmed is not counted.
The Simulator
New operators train and are assessed on a VR simulator before they spray a production face. The simulator records nozzle distance, angle, spray pattern, layer build-up and rebound for every scenario. The assessment result comes from that record. The simulator module is 2 days, with a third available if the scenarios need it, and all required scenarios have to be completed. On the Robotic course every candidate does the simulator module, experienced or not, because the examiner has to see them run the machine the right way. On the Hand Spraying course an experienced operator with 40 verified days may book it and is not required to.
The Practical Assessment
The final assessment is done on site with the examiner present. The examiner watches the whole cycle: the pre-start, the set-up, the start-up sequence at the nozzle, the spraying, the shutdown, and how the operator recognises and responds to a problem such as a rising line pressure or material that will not hold.
On the Hand Spraying course, an experienced operator who has not done the simulator sprays test panels during the assessment. The square panel is 600 x 600 mm at the design thickness with a minimum of 100 mm, sprayed at the production dose in the orientation of the work. Compressive cores are cut from it 7 days after spraying and tested at a laboratory.
Shotcrete quality cannot be inspected into a lining afterwards. Cores and panels show what was sprayed, and the operator determines it at the nozzle, pass by pass. The certificate is the client's evidence that the person holding the nozzle has done the theory, the verified days and an assessment that produced a record.
Before a crew mobilises, check each certificate against the work. A Hand Spraying certificate does not cover robotic work, and an expired certificate is not valid. Our courses, robotic and hand spraying, are on the training page with the modules and an enquiry form.
We run EFNARC nozzle operator courses for Robotic and Hand Spraying, on your site or at other locations by arrangement. The course pages have the modules and the enquiry form.
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