The evidence guide provides advice on assessment and must be read in conjunction with the performance criteria, required skills and knowledge, range statement and the Assessment Guidelines for the Training Package.

Overview of assessment

Critical aspects for assessment and evidence required to demonstrate competency in this unit

The evidence required to demonstrate competency in this unit must be relevant to worksite operations and satisfy all of the requirements of the performance criteria, required skills and knowledge and the range statement of this unit and include evidence of the following:

knowledge of the requirements, procedures and instructions for down-hole hammer drilling

implementation of requirements, procedures and techniques for the safe, effective and efficient completion of down-hole hammer drilling

working with others to undertake and complete the conduct of down-hole hammer drilling that meets all of the required outcomes

consistent timely completion of down-hole hammer drilling that safely, effectively and efficiently meets the required outcomes

Context of and specific resources for assessment

This unit must be assessed in the context of the work environment. Where personal safety or environmental damage are limiting factors, assessment may occur in a simulated environment provided it is realistic and sufficiently rigorous to cover all aspects of workplace performance, including task skills, task management skills, contingency management skills and job role environment skills.

Assessment of this competency requires typical resources normally used in a resources and infrastructure sector environment. Selection and use of resources for particular worksites may differ due to the site circumstances.

The assessment environment should not disadvantage the participant. For example, language, literacy and numeracy demands of assessment should not be greater than those required on the job.

Customisation of assessment and delivery environment to sensitively accommodate cultural diversity.

Aboriginal people and other people from a non English speaking background may have second language issues.

Where applicable, physical resources should include equipment modified for people with disabilities. Access must be provided to appropriate learning and/or assessment support when required.

Method of assessment

This unit may be assessed in a holistic way with other units of competency. The assessment strategy for this unit must verify required knowledge and skill and practical application using more than one of the following assessment methods:

written and/or oral assessment of the candidate’s required knowledge

observed, documented and/or first hand testimonial evidence of the candidate’s:

implementation of appropriate requirement, procedures and techniques for the safe, effective and efficient achievement of required outcomes

consistent achievement of required outcomes

first hand testimonial evidence of the candidate’s:

working with others to undertake and complete the conduct of down-hole hammer drilling

Guidance information for assessment

Consult the SkillsDMC User Guide for further information on assessment including access and equity issues.

Required skills

Specific skills are required to achieve the Performance Criteria of this unit, particularly for its application in the various circumstances in which this unit may be used. This includes the ability to carry out the following, as required to conduct down-hole hammer drilling:

apply legislative, organisation and site requirements and procedures for conducting down-hole hammer drilling

identify various thread types on the equipment at site and the application of prescribed torque

identify worn drill pipe and damaged threads

identify and measure various bits in use

correctly use the various rod/pipe handling equipment on site

correctly and competently add/remove rods/pipe from the string

correctly apply rotation speed and weight on the bit to maintain optimum performance

correctly measure line string components and calculate hole depth

utilise the correct combination of air volume and pressure to maintain productivity and sample integrity

collar holes

ensure that samples are correctly collected and handled

ensure that all string components are correctly maintained

correctly measure bits and related components to ensure compatibility

ensure that bit sharpening equipment, used to sharpen TC bits are used correctly and safely and that bits are sharpened to correct tolerances

correctly select various bit types for differing ground conditions

disassemble describing the function of components, inspect components, replace unserviceable parts and reassemble a DTH hammer

use prescribed techniques to safely clear sample delivery hose blockages

monitor sample quality and correctly interpret changes

accept responsibility for the correct installation and maintenance of restraining devices to pressure and sample delivery hoses

communicate the hazards of cuttings in the return air stream to all crew members

ensure that drill pipe is inspected regularly and wear rates monitored

ensure that threads are inspected and maintained as required

Required knowledge

Specific knowledge is required to achieve the Performance Criteria of this unit, particularly for its application in the various circumstances in which this unit may be used. This includes knowledge of the following, as required to conduct down-hole hammer drilling:

critical need to match like threads with like threads on all tubular components and make up torque requirements

parameters relating to wear of drill pipe and integrity of threads

function of hole collaring

methods required to limit the contamination of samples

theory behind TC bit sharpening

bit selection for different types of drilling and different ground conditions

problems related to inaccurate measurement of bits and other related components

importance of monitoring sample quantity

role that blockages play in affecting sample quality

methods commonly used to clear down hole blockages in air drilled holes and the hazards associated with clearing blockages

methods used to clear a blockage in a sample delivery hose and the hazards associated with clearing blockages

critical need for restraining devices to be fitted to all pressure delivery hoses and sample delivery hoses, the devices available and their methods of attachment

dangers of drilled samples being returned to the surface at high velocity in air drilling operations and the parameters involved

importance of checking gauges and monitoring pressures, flow rates and temperatures

Relevant compliance documentation may include:

legislative, organisational and site requirements and procedures

manufacturer’s guidelines and specifications

Australian standards

code of practice

Employment and workplace relations legislation

Equal Employment Opportunity and Disability Discrimination legislation

Work instructions may come from briefings, handovers, plans and work orders and may be written or verbal, formal or informal and may include:

nature and scope of tasks

specifications

quality of finished works

achieved targets

operational conditions

obtaining of required permits

site layout

out of bounds areas

worksite inspection requirements

lighting conditions

plant of equipment defects

coordination requirements or issues

contamination control requirements

environmental control requirements

barricade and signage requirements

Hazards may include:

working in proximity to drilling rig

injuries to fingers, hands and back

incorrect speed of operation

inadequate maintenance

heat, dust, fatigue, dehydration

high pressure air discharge

leakage of couplings

flailing components

flailing couplings

fire

rock fall

void ground

Coordination requirements may include:

other equipment operators

maintenance personnel

supervisors

site personnel

Tools and equipment may include:

drill rods and drill pipe including:

conventional drill pipe

API threads

BECO threads

thread protectors

drill bits including:

DTH hammer concave, convex and flat face bits

rod handling equipment:

manual handling

mechanised rod handlers

hydraulic pipe/rod/clamps

hydraulic pipe/rod/spinner

make and break:

stillsons

hydraulic tongs

pipe wrenches

pipe/rod spinners

hydraulic make/break devices

make up torque requirements

bit break out plates

Driller’s duties may include:

using correct rod to hole diameters

selecting best bit configuration for ground and hole conditions

maintaining correct rotation speed and weight on bit for optimum penetration

calculating line string and hole depth

using correct combination of air volume and pressure to suit drilling conditions

monitoring collection, splitting and bagging of samples

ensuring all equipment is kept clean and stored correctly

ensuring principles of good housekeeping are followed

measuring bit diameters

Restraining devices may include:

internal/external whip checks

full ‘sock’ whip checks

anchor points

hose fittings

Fluids may include:

dust control additives

water

Sample and sampling tasks may include:

air core samples

DTH samples

Maintenance tasks may include:

sharpening button bits, cross bits

using grinders, bit sharpening machines

line string components (e.g. drill rods, subs, stabilisers, couplings, air swivels)

drill bits