CPCS A58 Excavator 360 Below 10 Tonnes Course

1. Introduction

The course consists of both theory and practical sessions aimed at teaching a candidate how to operate a 360 excavator safely and effectively. Group discussions, syndicate and individual activities, and case studies will be used to allow candidates to share their knowledge and experience of excavator operations. Candidates will be given a comprehensive all-round understanding of both the operator’s and the machine’s capabilities and limitations.

The CPCS A58 Excavator 360 below 10 tonnes course will enable candidates to: a) Understand and comply with manufacturers’ instructions in accordance with the operator’s handbook, other types of information sources and applicable legislation. b) Undertake all pre-use checks. c) Configure and set for travel. d) Travel over rough, undulating ground, substantial inclines and level surfaces. e) Manoeuvre in confined areas. f) Excavate differing types of holes and trenches. g) Backfill and tamp holes and trenches. h) Grade, spread and level differing types of materials. i) Load and unload differing types of vehicles. j) Lift and move freely suspended loads. k) Place spoil into various types of tips and hoppers.

The CPCS A58 Excavator 360 below 10 tonnes course is designed to provide candidates with a thorough practical and theory training in operating a 360 excavator. This course is suitable for anyone who wishes to undertake a career in operating a below 10 tonnes 360 excavator either in the construction, utility or landscaping environment.

1.1. Course Overview

The course covers the role, responsibilities, and safe working practices of the operators of 360-degree excavators, and also the needs of other employers who may need to supervise or task the operators. The course is of a practical nature based around an assessment. Candidates for training and assessment should be advised that there is a strong element of physical activity and manual handling required and they should be prepared for both. The course aims to provide the candidate with thorough practical and theory training in operating a 360 excavator, to enable the candidate to attain the CPCS Red Operator Card. Candidates will gain knowledge of hazards and risks associated with 360 excavator operations, and how to control them. This is to ensure the candidate provides evidence that they can keep themselves and others safe. Learn all aspects of 360 excavator’s maintenance; through a theory session and maintenance checklist. Understand the basic principles of the machine’s duties and to be able to locate and identify the major components of the machine and explain their functions. This will help the candidate understand how to operate the machine to its full capabilities and also identify any problems that may occur during the machine’s working life. All tasks are completed with a method of risk assessment and a safe system of work. Theory sessions are backed up with DVDs and a course booklet. On completion of study for the theory and practical elements, the candidate will undertake a theory knowledge test. The course overview is for 360 excavators below and above 10 tonnes. The objectives are a list of what the candidate should be able to do on completion of this course with the achievements listed below. This course is designed to give novice operators knowledge and understanding of the 360 excavator, a machine that is widely used within the construction industry. This is intended to provide candidates with a foundation to progress in their career development to the role of a plant operator. Experienced operators will also benefit from the course and will be able to identify any gaps in their knowledge. This will allow them to refresh their understanding on some fundamental issues and also get up to speed on recent industry changes.

1.2. Objectives

The solutions to both theoretical and practical situations are integrated into the delivery and the course is flexible to the needs of the individual and the employer. The course is for plant operators who have received little or no formal instruction and those who wish to brush up on their skills. This excavator 360° (below 10 tonnes) course is aimed at operators who are required to work the machine both in confined and open areas. All candidates must have a basic understanding of the current Health & Safety issues. This can be incorporated with the ‘approved code of practice’ and other regulations relating to excavating operations. Whether novice or experienced operators, we have a course that 360 excavator course for you. We are accredited with the CPCS (Construction Plant Competence Scheme) and on successful completion of your practical test you will be issued with the relevant CPCS Trained Operator Card. Duration varies depending on the experience of the candidates. The 360° excavator course can be anywhere between 1 and 10 days. Novice operators with little or no experience on the machine will need a 10-day course. Experienced operators, looking to take a short course of formal training and test for the RED card, will only need 1 to 5 days, depending on experience. On some occasions when an experienced operator has received thorough familiarisation training the duration can be just 1 day but this is down to the centre’s discretion.

1.3. Target Audience

Firstly and foremost, this course is for learners with limited or no experience of operating a tracked or wheeled 180° excavator below 10 tonnes. A62 would be a more appropriate course for learners needing to prove their ability operating a machine above 10 tonnes. People who are aiming to refresh or re-validate their skills would also be well suited to this course. Typical roles could include operators working within utilities, fencing, landscaping, and highways maintenance, and is also suitable for those employed in a more general role that requires the operation of a 180° excavator below 10 tonnes. This course will enable learners to progress to an intermediate qualification in a relevant construction occupation. Learners can also progress onto the CPCS NVQ Level 2 in Plant Operations. The achieving of these qualifications will enable learners to enter into supervisory positions. This course meets the requirements for learners who work or want to work in construction involving operating 180° excavators below 10 tonnes. This course provides a varied mix of both practical skills and theoretical knowledge. All employees or self-employed persons who are in this field of work must now be trained to the standards set by the Construction Industry Training Board (CITB) and also the Occupational Safety and Health Consultants Register (OSHCR). This course can often be funded by the CITB, who provide grants for employees. The CPCS qualification is recognized throughout the construction industry. It is ideal for employers who wish to get their workforce up to an approved standard without the inconvenience of sending them off-site to an alternative location, and it is also suitable for those wishing to achieve a qualification to improve their job prospects in their own time.

2. Excavator Components

During the first practical exercise, trainees are required to identify various components and explain their function and significance to the machine as a whole. It is crucial that this module is delivered in a classroom environment with the aid of a visual presentation. Trainees will have the opportunity to ask questions and seek clarity on various components. Trainee participation and interaction is encouraged. The trainer should be critical, asking questions to the trainee relating to their current job role or possible job role. This will ensure that knowledge gained is relevant and understood. This module will cover: – Mechanical Components – Engine – Hydraulic System – Electrical System – Undercarriage and Dozer Assembly – House and Swing Mechanism – Operator Compartment – Attachments and their Functions Each of the above will be broken down into various components. All units have a “Component Identification” list available from CPCS. This module will require the trainer to have various excavator components for trainees to actually handle and identify. This is a classroom activity designed to meet the various learning styles of individuals. The material in reference to the modules would be the Excavator itself, various real components used as visual aids, and a PowerPoint presentation to display various excavator components. This provides organization and clarity. The method of instruction will consist of an explanation from the trainer with questions and answers. Trainees will be expected to participate. This will ensure that they are more engaged and the learning is more interactive.

2.1. Basic Structure

The house is connected to the base by the center slew ring. This allows the house to rotate 360 degrees on the base, allowing the digger to work in any direction. This is a major advantage over a wheeled machine, which is capable of only back and forth movement, unless it is repositioned.

The house sits on top of the base. It serves as the platform, the part that remains stationary while digging. The platform also provides protection for the upper parts of the engine and supports the upper works that house the control mechanism and the machinery the operator uses. The engine is usually attached to the underside of the platform on the house. This has the advantage of simplifying the engine access.

Digger is primarily a digging machine. It consists of a base with tracks or wheels, a body that connects a platform and house, and a boom, dipper stick, and bucket.

Section “2.1. Basic Structure”

2.2. Engine and Powertrain

The engine provides the excavator with power to move against resistance or load. The main differences between a hydraulic excavator and the majority of other heavy equipment are that rather than using a gearbox and driveshaft to transfer power to the wheels or tracks, the majority of the power is transferred through the hydraulic motors which are extremely efficient. Excavators are also able to swing and slew (pivot and turn in a circle) using a large amount of power from the hydraulic motors. This is a far more efficient use of energy than a mechanical system using a winch and cable. The slew system on an excavator is also entirely in a closed loop, using the hydraulic pumps and motors. This is a far more controllable system offering precise power and control, normally required when carrying out a lift and swing operation with a heavy load. The function to be able to dig and travel simultaneously is also more efficient on an excavator than other digging machines. This is because the hydraulic system is able to supply force and power to the different functions to carry out a combined operation without loss of digging power. This is in comparison to other machines which would require the brakes releasing to give movement, resulting in less power to the digging implement.

2.3. Hydraulic System

In modern excavators, hydraulic systems are key. These hydraulic systems are mainly comprised of a pump, control valves, a tank, a filter, and the actuators. Actuators could be a cylinder, a motor, or a hydraulic motor/pump. These are all connected by hydraulic pipes and hoses; a simple system but a great deal of power can be transmitted. Movement is created by flow and pressure. The pump supplies the oil to the control valves; depending on the position of the valve, oil will flow through the valve and into the actuators, ultimately moving them. The hydraulic energy that is created is then converted to mechanical energy to produce movement. Due to the limited movement of excavators, hydraulic systems are ideally suited to the demands of this machine. A hydraulic system is far more versatile than mechanical, electrical, or pneumatic. It also has the advantage of easy-to-understand building and repair. The main drawbacks of hydraulic systems are that they can be inefficient, use a lot of space, and their oil can be quite costly. In the case of excavators, none of this really matters. It’s more important that it’s easy to control precise movement; this is something no other system can achieve.

2.4. Controls and Instruments

The operator control system can be either hydraulic or mechanical, with the hydraulic systems being the most popular in the UK. So, these are the ones that are covered here. The main hydraulic pump is driven by the engine’s flywheel. This can be either an over gear (a secondary connection on the gearbox) or direct drive from the flywheel, and is often known as a pump fly engine. This pump supplies oil to the control valve, which is usually a bank of several valves of the monoblock type. The control valve’s purpose is to direct oil to the actuators as and when required. This is achieved by the spool inside the valve being moved by mechanical means to allow and disallow flow to the actuator. The spools in the control valve are connected to the lever in the operator’s cab by a linkage of sorts and can be either one-to-one or pilot operated. One-to-one being direct and pilot operated being a link from the lever to the pilot valve and then onto the control valve. It is called pilot operated because the higher pressure from the control valve is redirected to the pilot valve to move the spool.

3. Excavator Safety

Pre-Operational Checks Personal Protective Equipment (PPE) Safe Operating Procedures All these areas require attention in their own right, but ultimately the operator is the key to safe and successful excavation operations. Safety is no accident.

The major cause of fatal injury in the excavation industry is from overturns, the second being from contact with an overhead power line. All excavator operations require a competent, trained, and cooperative operator using a safe system of work. Before commencing any operation, a risk assessment should be carried out to establish the safest method of excavation. This will vary depending on site conditions, ground type, and the location and type of services in the work area. Excavator safety is a broad subject, and all aspects of excavator operation should be considered when looking at safety. We have broken this down into three areas:

3.1. Pre-Operational Checks

Ensure that you are familiar with the layout and controls of the machine, and know where the emergency stop buttons, fuel and hydraulic fluid gauges, and the suspension seat control are located. Thoroughly inspect the machine for damage and the security of all fittings and guards. Ensure the grease and dirt are cleared away from all greasing points. You are now ready to start the pre-operational checks. Answer the questions listed in the pre-start check section of the handbook. This will enable you to pick up any reported faults before starting the machine. Remember to refuel the machine using the correct specified fuel. A machine with contaminated fuel will not run correctly and will become a future maintenance problem. Fill out the fuel and lubricants record found at the rear of the handbook to enable you to monitor the machine’s thirst. Run the machine for 5-10 minutes to check that all gauges and functions are working correctly. Now stop the machine and conduct the first circle check cleaning your windows as you go.

3.2. Personal Protective Equipment

A high visibility waistcoat or jacket is compulsory for all machine operators working on roads or construction projects within 15 metres of the public highway. High visibility clothing requirements are laid down in the Health and Safety (Safety Signs and Signals) Regulations 1996 and the Personal Protective Equipment at Work Regulations 1992.

Safety footwear should comply with BS EN 345 for toe cap protection with further requirements to meet various safety standards for different working environments. Remember the protective qualities of the footwear will only be effective if the correct size and type for the user is selected.

The safety helmet must comply with the latest issue of BS 6658. Safety helmets are designed to provide protection against head injury and will vary according to the method of construction of the shell and the materials used. The most useful feature of the helmet is the harness, which is effective in keeping the helmet comfortably on the head and protecting the skull against impact from falling objects.

The following PPE items are considered the minimum requirements to ensure safe operation of an excavator: – Safety Helmet – Safety Footwear – High Visibility Waistcoat/Jacket – Hearing Protection – Eye Protection – Gloves

Excavators are hazardous tools and should be respected as such. All practicable steps should be taken to ensure the safety of personnel. Personal Protective Equipment is an important step in reducing the risk to the operator and others working in the close vicinity of the excavator.

3.3. Safe Operating Procedures

Never carry out an operation with which you are not familiar without first seeking instruction. Stop the machine and seek advice if you are unsure about the safe method of work or if you are not certain about the location of underground services. Be aware of the swing area of the machine and take the machine’s size into consideration when digging. Do not swing the machine beyond the safe working area and do not encroach into an adjoining live lane of traffic. If work has to be carried out within close proximity of the machine tracks, the ground should be properly assessed to ascertain the stability it will support. Do not work on a slope steeper than that which is stated in the handbook, if you are in any doubt about the slope angle do not work on the slope. Do not attempt to cross a ditch or excavation with water flowing into it without first assessing the watercourse stability. Never attempt to climb out of a ditch or excavation with bucket or dozer blade – this common practice can result in the machine overturning. Do not attempt to access a work area by exceeding the gradients stated in the handbook. Do not carry out manual ground working operations, i.e. pulling or pushing the machine from behind while track levers are operated to move the machine, without first assessing the stability of the machine during such operations. Always think ahead and envision the path in which spoil is to be carried ensuring that this does not involve excessive travel across uneven or sloping ground and always check that the area in which the spoil is to be deposited will support the machine. During truck loading operations, only load trucks of a type or design that is suitable for use with excavator loading operations. When machine is to be parked on a slope, the bucket should be placed on the ground above the upper side of the slope and the blade or counterweight should be used to secure the machine. This is only an emergency means of securement and should never be used during normal working operations. Always wear a seat belt. Wait for a quiet day to try to find one!

4. Excavator Operation

You cannot start the machine unless the area surrounding the excavator is clear from obstructions, this includes people. Check the controls are in the neutral position, move the hydraulic control levers to release any built up pressure and warm the engine, excessive idling is not recommended. The low idle setting should be used if stopping for a short time. Read the manufacturer’s manual so you are fully aware of all the functions of the controls, there are two main types of control for an excavator, these are ‘excavator’ and ‘backhoe’ controls. Set the control levers to the corresponding position, place the travel lever in the neutral lock position and release the parking brake. All controls should be in the neutral position to enable free movement of the machine, the levers can then be operated to apply various movements. An efficient way of controlling the speed of the tracks is to use the travel lever in the forward position, this will allow a change in travel direction and free movement of the levers to carry out any extra functions. To change the excavator from a tracked machine to a mobile machine, the front blade can be used to push material, the excavator can then be turned 180 degrees and the backhoe used for digging. To stop the machine, all levers should be returned to neutral and the parking brake applied. Excavators are versatile machines and are designed to do many various tasks so also the operator requires a good working knowledge of a wide range of tasks. Good basic technique is often common sense and is dictated mainly by the type of material being excavated, work needs to be methodical and well planned with regular observation of the surrounding conditions to check for any changes. A good operator is always aware of any underground services and uses safe digging practice to avoid damage to them. A quality job can be very rewarding and should give satisfaction in conserving the machine in the best possible condition with regular maintenance and a good knowledge of fault diagnosis.

4.1. Starting and Stopping

Now to put this into practice; prior to digging ensure visual check of surroundings to determine if there are any obstructions in the way of tracking off of the dig area to the spoil heap. Now carrying out the previous method of continuous lever movement on one side and using the other track to light at the point where the access way is to begin. This will result in a spin round with the high side being the centre of the turn. On completion track the machine forwards. Now the right hand pattern is reverse so the left hand track is continuously pressed forward, there is a need to spin around to dig back the other way and swing of the machine will achieve this with minimal repositioning. Now for loading truck astray method can be used to achieve the same course change into the approach and a mechanical 180° swing can be later used to pick up the return access way and begin the digging process. Speaking of change course into the truck loading position, it is much simpler as a straight continuous turn can be use with a slight input of the high side tracks to anti-slip the machine and finish with a forward tracking manoeuvre.

The digging position is a semi-squat stance with the right hand track in reverse and the left hand side pushing forward. This method allows easy tracking forwards or backwards with straight manoeuvring capability into an access way (trench), or in and out of a truck loading position, with the added advantage of being able to spin the machine 360° by increasing the pressure on one side with the opposite lever movement. Step turns can be carried out by using a single track to pivot about. This is achieved by stopping movement of one track and pressing the opposite lever continuously, this in turn will cause the machine to raise up on one side allowing the track that is moving to pivot the machine on the high side.

Before you start the engine, quadrant and grease the front and rear ends of the undercarriage. This is essential as an excavator is built to dig, and the track system is especially susceptible to dirt and small stones which can cause damage. It is also lighter on the tracks than when it is to be used for digging, therefore leaving it level will cause less wear and tear all round. If excavation is to be carried out on a slope, it is advisable to remove the dozer blade and fit a bucket to act as a counter balance on the opposite end of the slope. This method is employed instead of blocking the tracks because it maintains an even weight distribution on either side of the machine.

4.2. Maneuvering and Positioning

An excavator is a machine with many uses and abilities. One of the most basic uses is its ability to move, so it is important to know how to manoeuvre the machine safely. When the track-mounted machine is compared to the rubber-tired machine, it is slower and less mobile. The use of the blade is essential to both, providing grip and stability. When the tracks are in good condition, the machine can move in any direction without creating too many ruts. An efficient operator should be able to change the travel lever from forward to reverse and steer the machine in one movement. A good way of lessening undercarriage wear is to slew the machine in the direction of travel and avoid sudden changes of direction. Turning in confined spaces can be difficult. A good technique is to lift up one side of the tracks and break into the turn. Once the turn is initiated, place the tracks down for added stability. When working on gradients, it’s important to travel up and down the slope for added stability, never across. Consideration should be taken when working near trenches as it may be possible to travel over the trench and cause it to collapse. This can be avoided by using the correct machine for the job. The tracks can be removed from the excavator and it can be lowered into the trench using a suitable lifting attachment. Always consider the ground condition to avoid getting the machine stuck. A balanced spread of the tracks is essential when working on soft ground. By positioning the machine off-center, it’s possible for one side of the tracks to get stuck.

4.3. Digging and Loading Techniques

The general principles for achieving good muck shifting are transferable to all types of excavator, but it is obviously more relevant to the larger quantity production machines. It would be beyond the scope of this module to describe every type of excavation activity an excavator may undertake, so the module will focus upon the standard operations of digging to load directly into haul trucks or for stockpiling, and trenching. Excavators are generally ideal for loading into haul units because of their ability to control the dump height of the bucket. When trenching, the machine can use an elevated work platform by raising the tracked undercarriage. This gives the operator good visibility and loading angles, and it is particularly useful in deep trenching applications with long reach machines. Step one in any type of digging is to position the machine correctly in relation to the work. The basic objective is to load the bucket to its optimum working capacity. This is achieved by positioning the machine such that the distance and height the bucket has to travel to the digging face is as close as possible to the optimum operating range of the machine. This will obviously allow the quickest cycle time, and the most efficient use of fuel…and time is money! In the case of direct loading into haul units, it is important to factor in the angle of reach and dump height of the loaded bucket, and the return travel of the machine back to the digging face. Cycle time is further increased by positioning the truck such that the distance and direction of travel between the digging face and the truck is catered for. When working in conditions of a more restricted nature, such as urban areas, or in and around demolition sites, etc. It is important to be aware of minimum swing dimensions of the machine and the work area requirement for safe and efficient operation of the excavator. Always, any excavation activity should take safety into consideration at every stage in the planning and execution of the work.

5. Excavator Maintenance

5.2. Lubrication and Fluid checks: Correct lubrication is of little use without the right lubricant. Always use the type of grease recommended in the operator’s manual, taking care to prevent debris entering the greasing points. Make sure to keep a record of all lubrication to prevent over or under greasing. Grease at the specified intervals, or more in harsh conditions, purging the old grease of any contaminants. Any leakage found should be corrected without delay. Daily walk-around checks should locate any leaks.

The condition of the bucket and any attachments are critical to safe operation – pay particular attention to the condition of the bucket, in particular the security of the cutting edge. With the engine switched off, all guards need to be checked for damage, security and cleanliness. Take note of any required cleaning and schedule it when possible. All radiator shutters must be working correctly. Finally, and perhaps most important, clean all windows and mirrors and make sure that the operator’s manual is clean and in the cab for reference. Any defects found should be corrected without delay and noted for future preventative maintenance. A large factor in the logistics of your inspection is planning how to rectify problems found. Now the machine is ready for start up.

5.1. Daily Inspection and Maintenance: All exterior glass and mirrors must be in place with no damage. Ensure the wipers are not damaged and operate correctly. Check the warning beacons and work lights are all functioning. All steps and handholds need to be secure with the handrails in place and not damaged. Tracks must be clear of debris and in good condition with correct tension.

Before you start up your excavator, it is important to do a complete walk-around checking for any visible problems; taking note that any corrective action should be taken.

5.1. Daily Inspection and Maintenance

The operator should, as a matter of course, carry out the following inspection at the start of each shift and also as required throughout the shift. a. Tyres or tracks: condition and pressure. b. Transmission: for correct response in direction and speed, unusual noise or vibration and also heating up. c. Engine: for correct operation of all gauges and warning lights, unusual noise or smoke in the exhaust, heating up and correct response to acceleration. d. Hydraulics: correct response to operating levers, unusual noise, smoothness of operation and heating up. e. All controls for unusual free play and correct response. f. Hitch and attachments: security of attachment, correct movement and operation. g. For any fluid leaks in the transmission, engine, hydraulics and also fuel, water or air conditioning system. The respective fluid level checks are as follows: a. Engine oil. b. Transmission oil. c. Hydraulic oil. d. Coolant. e. Fuel. f. The air conditioning refrigerant level cannot be checked and should only be done by a qualified engineer.

5.2. Lubrication and Fluid Checks

Water is the most common contaminant found in hydraulic systems and can reduce the life of components through erosion, reduce the lubricating qualities, and possibly cause the oil to emulsify. This happens regularly in hydraulic tanks if the breathers are damaged. Checking and cleaning the breathers is a good habit, and by keeping the dirt and water from the tank, the occurrence of this and many other problems will be minimized. Always be sure to check oil levels after draining and also when changing the type of oil, as different oils have different levels of compressibility, and this may lead to the oil level reading incorrectly.

When changing the engine oil, it is a good idea to run the engine prior to draining as this will heat up the oil and drain much more efficiently. Be sure to run the oil level down the dipstick before adding more oil; overfilling the oil can cause excessive pressure and leaks. Changing the oil and fuel filters regularly will help to ensure that clean oil and fuel are being used in the machine. This is important as using dirty fluids can cause damage to the engine’s internal parts. When changing hydraulic oil, it is vitally important that the correct oil type is used due to the many different hydraulic systems and the differing specifications involved.

When lubricating pins and bushes, it is important to use the correct type of grease. Hand greasing is the best way to ensure that the grease is going exactly where it is needed, and the only way to ensure this is to know when the joint has taken enough by seeing excess coming out of the joint. Often too much grease can be put into a joint, and this can cause the seal to be broken, resulting in a loss of lubricant and dirt getting into the joint. Grease must not be put into the bucket or dipper cylinder (if hydraulic). This can often happen when trying to lubricate the joint between the bucket and dipper, but there is already ample lubrication provided by the attachment pin, and having grease going into the cylinder will often damage the seals.

There are many different types of lubricants and fluids out there that are used in machines. They are used to reduce the wear and tear of the many different moving parts within the machine. The service life of these parts and therefore the machine itself often depends on maintenance of the fluid condition. Wrongly chosen or often over-diluted lubricants and fluids can often do more harm than good and can lead to costly repairs.

5.3. Troubleshooting and Basic Repairs

When you have followed all the previous advice, you should not have a great need for this section. But inevitably, you will experience problems with the machine during its working life. It is unlikely that you will be able to diagnose and rectify all problems on-site, but it is important that you establish how serious the problem is. It may be useful to complete a simple repair to keep the machine working until you have time to take it out of service. Always refer to the manufacturer’s manual for a more detailed diagnosis and repair. A sound knowledge and regular implementation of the daily checks will ensure that you are familiar with your machine and can sense when something isn’t right. It is at this stage that you will decide if the problem is something you can fix on-site or if it needs professional attention. Below is a guide to some basic checks and repairs that may be undertaken. Firstly, establish the symptoms of the problem and decide whether it may be a risk to continue working. If the problem is something minor, then it is likely that you will be able to continue working with a periodic check on the problem. If the problem is causing an effect on the safety or capability of the machine, then it is advisable to take the machine out of service. Always consider the danger and damage that could occur by operating the machine with the problem. Often, a small problem can be greatly exacerbated by operation of the machine with said problem.

6. Excavator Attachments

Although the bucket is deemed to be the most used excavator attachment, there are also a few others which can be used for specific types of work. Augers are used in boring holes for footings, signs, fencing, and also drilling for blasting purposes. The auger attachment consists of a drill bit with flighting to remove the excavated material. Once the hole has been dug with an auger, it will often be cleaned out with a mud or GP bucket. A thumb is an attachment often used for demolition work. It is similar in appearance to a backhoe thumb but is attached to the excavator stick. The thumb can be used to pick up and manipulate small items and debris and also to hold and sort larger items. A tilt rotator is a modern excavator attachment. It is a hydraulic attachment which gives the excavator the ability to rotate any attachment 360 degrees and also tilt +/- 45 degrees. This provides a great deal of accuracy and flexibility in excavating.

Excavators have several attachments, which can improve their efficiency to a great extent in performing various kinds of work by digging. Attachments vary in design and are pertinent to the kind of work to be performed. The bucket is the most common and simplest of the excavator attachments. It is used for digging and is available in many different types. The most common of these is the ‘general purpose’ or GP and is used for the digging of trenches and all types of excavation and also loading of soil and other materials. It has a wide, slightly concaved blade which serves to pick up the excavated materials. GP buckets are also available with a rear door to allow automatic dumping of material by curling the bucket. Wide and ‘mud’ buckets are the other types used in trenching. They are used to dig large trenches of a specific width and are often used in drainage projects. Step-sided buckets come in toothed and smooth varieties. They are used for general purpose digging in hard and compact materials such as rock and concrete. The final type of bucket is the sorting or ‘griddle’ bucket. These have a much stronger sieve-like basket construction and are used primarily to separate materials. A griddle bucket is often used in cleaning up demolition sites to separate rubble from soil.

6.1. Bucket Types and Uses

There are several types of buckets available with excavators. The most common are: General Purpose (GP) – used for most operations, including digging and loading. Heavy Duty (HD) – similar in application to the GP bucket, but has a more robust construction. Mud – has a wider blade, often with holes in it, to allow mud to fall through. This type of bucket is commonly used when working in rivers and where there is soft ground. Rock – has a more pronounced curvature of the blade, often with a single pointed tooth on the front. The bucket is often reinforced with a wear plate on the underside. This type of bucket is used when it is anticipated that there will be a high degree of wear. Shaker – a specialized bucket used for sorting materials. It has a variable gap between the tines which are used to sift the material. There are also buckets available with tilting mechanisms which allow the bucket to tilt about a transverse axis. Tilt buckets are available with hydraulic or mechanical tilting, and are used when an even grade is required on the surface being worked on.

6.2. Changing and Adjusting Attachments

– Assess the job and decide on the type suitable. Remember attachments are designed to perform specific tasks and multi-purpose tools are usually a compromise. – Assess the density of the material to be handled. Heavier materials/compaction will require a more powerful excavator as the attachment will be working through the material. For example, a trenching bucket as compared to a heavy-duty rock bucket. – Assess the size of the material to be handled. An oversized attachment or mismatching the type required can result in inefficient operation and undue wear on the machine and attachment. For example, a large bucket to remove small tree stumps or a small bucket on a large tree stump. – Always familiarize yourself with the manufacturer’s guidance on the correct use of the attachment. This information will ensure maximum productivity and safe operation.

Choosing the correct attachment for the task to be undertaken is important. Below are some general guidelines on matching the attachment to the task:

6.3. Safety Considerations for Attachments

Effective attachment use demands understanding the attachment and its use before doing the job. Studying the manufacturer’s instructions is a good start. Sometimes the instructions are missing, hard to find because they have been thrown casually in the accessory storage area, or have been destroyed through overuse. What’s more often the case is that a good way of using the attachment to best effect with the machine, proper safety and maintenance practices included, have not been thought out in the first place. Equipment “managers” – and that’s often the machine operator – should develop a system of recording key information from the manufacturer at the time an attachment is purchased, and a readily available equipment history file should be kept with the machine so that instructions and records can’t get separated from the attachment. When considering purchasing an attachment, it is worth keeping in mind the “principal contractor” aspects of the 2015 CDM Regulations. The project client can unwittingly be the “principal” and the responsibility for handing over a piece of equipment to another contractor for use with the attachment is the same as providing a piece of plant for hire with an operator to carry out a particular task. This part of the law is now applicable to the owner of a single farm or a large construction company. Health and safety implications for using an attachment incorrectly can be serious and never worth the risk.

7. Excavator Site Hazards

7.2 Overhead Obstacles Excavators are occasionally required to work in areas where there are overhead obstacles to cause damage to the cab and its protective structure. Typical obstacles are bridges, the soffits of buildings, the rear sides of lorries or other excavators. Static plant may be used to push or pull objects into the path of the excavator. Excavators have been overturned when work has been conducted adjacent to excavations with soil heaped between the excavation and the obstacle. Static tipping and rollover of the excavator are the most common forms of overturning and working on a reduced level may increase the severity of the upset. To avoid inadvertent collision with overhead obstacles, practical training and planning the work via method statements can be undertaken. Where there is possibility of collision a risk assessment for that task can be made outlining the safe system of work and precautions to be taken.

7.1 Underground Utilities There are an increasing amount of services being laid underground and it is essential that before mechanical excavation is commenced, enquiry is made as to the existence and position of the services. The use of cable and pipe location equipment and competent persons is essential. Even so, it may not be possible to precisely locate the services. In such cases safe systems of work using trial holes and hand working may have to be adopted. Some services and sewers have been laid in embankments which have subsequently been cut through by road and rail construction. It may be difficult to detect the existence of the embankment and the first knowledge of its existence may be when it is approached by the excavator. When working at or near services, advice should be sought from the service owner as to the nature and position of the work and the precautions to be taken. If there is risk to the service the work may have to be abandoned.

The following three subjects have been found to be the largest causes of damage to excavators on site. Each of them is covered in turn.

7.1. Underground Utilities

The employer showed the underground services plan and explained to me the type of work that was to be undertaken. I also confirmed the location of services, especially in areas where work was not planned, and the agreed no-go zones. I used safe digging practices throughout and located services in areas around work that were previously unidentified by the employer. I used suitable detection or location equipment and other hand tools such as insulated shovels to expose services without causing damage to them. I identified utility services including gas and electricity, street lighting, telecommunications, water, and sewage. I confirmed the depth of each service and the materials that it was comprised of. At times, I also discussed with utility company representatives the best methods to uncover and expose their services. I recognized and avoided endangering surrounding structures, for example, retaining walls, manholes, or drainage points by ensuring that no debris fell into them or that no damage occurred as a result of excavator operation. I identified and recognized near misses where service damage could have occurred and took appropriate action to prevent it. This all enabled me to work efficiently and safely around services, maintaining productivity and minimizing damage and service disruption.

The work “CPCS A58 Excavator 360 Below 10 Tonnes Course” is an equipment training course for staff employed in the construction, civil engineering, or plant operations sectors. It is important in these areas to acquire good and reliable skills in the operation of the 360 excavator below 10 tonnes. The course will help candidates understand the basic principles of the machine’s systems, controls, and components, as well as the sector-based activities. This includes getting the machine ready for travel, before and after operating procedures, and understanding the capabilities of the machine and attachments based on the information provided by the site management on what needs to be achieved. Step by step, the candidate will develop their skills to become a safer and more efficient operator. The course outcome will result in a CPCS Trained Operator Card or a Red trained operator card for candidates who do not complete the CPCS technical tests during the course.

7.2. Overhead Obstacles

Just before moving on to digging activities, the operator should look above his head to identify any potential overhead hazards. An overhead hazard could be anything which may fall from above or cause damage to the operator. This could include buildings, trees, working on high ground, etc. If there is a risk of potential overhead hazard, the operator must ensure that exclusion zones are set up and clearly marked. This will restrict access to the work area and help to protect those persons at risk. The greater the risk, the larger the exclusion zone needs to be. If the overhead hazard is relatively minor and there is no other way of eliminating the risk, it is possible to continue work by using alternative methods such as extended reach attachments or a long reach machine. This enables the work to be carried out at a safer distance from the hazard. A banksman should be used when digging near an overhead hazard and always watch the direction of the dig end in relation to the hazard.

7.3. Slope Stability

Slopes are one of the most common geographical hazards excavator operators will encounter. A slope is an inclined surface of the earth. The steeper the slope, the greater the likelihood of a landslide or slip occurring. The angle of repose of the material is also an important factor in determining slope stability. The angle of repose is the steepest angle at which a sloping surface formed of a particular loose material is stable. Any steeper and the material will begin to slide. Excavation in a cutting is a common activity an excavator operator may carry out. The spoils from the excavation are often deposited at the top of the cutting; this can impose a greater loading on the slope. It is good practice to try and deposit the material on a bench further down the slope, this will reduce loading and help prevent a slip occurring.

8. Excavator Load and Weight Management

8.1. Load Capacity and Limits The majority of mini and midi excavators have only basic lifting capabilities, i.e. lifting hooks at the base of the dipper arm and a lifting eye on the back of the machine. They are likely to be used for light lifting, and as a general rule, the smaller the machine, the smaller the load that should be lifted. It is essential that the machine operator is aware of the load capacity of the excavator. This should be confirmed from the machine’s operating manual or from the manufacturer/dealer. The specification should be of a maximum load in kgs and also the maximum load radius. This represents the furthest distance from the slew bearing centre that a load can be safely lifted. Any lifting outside of this specification is potentially dangerous and should not be attempted. This reading must be interpreted as the load weight PLUS the weight of any attachments slung under the lifting mechanism. For example, a load weight of 1000kg with a stated weight of 100kg for a pair of lifting chains on a set of chain slings gives a total load weight of 1100kg. Calculation of a load’s centre of gravity and assessment of whether it can be safely handled without risk of tipping the machine comes under a combination of stability and weight distribution analysis. Such a lift would place extra demand on the excavator to lift it safely beyond the specification that the chains were calculated at. A factor of safety beyond a load’s minimum weight capacity must always be taken into account. For example, if the machine has a lifting capacity of 1000 kg, a lift of 950kg is near the machine’s limit and too close for comfort. A safer limit would be put at around 800kg.

Although the excavator is primarily a digging machine, it is used frequently for lifting activities. These may range from light work such as handling pipe or kerb sections to more demanding tasks like placing pre-cast concrete and erecting structural steel. This type of work is potentially hazardous and can present a serious risk of injury to operatives and other site personnel, as well as a significant risk of damage to the plant and the load.

8.1. Load Capacity and Limits

An excavator has its own weight and the pressure that it creates. In order to avert the likelihood of a tip-over, the excavator shall be situated on firm level ground. The capacity, of which the excavator can handle on a certain task, has to take into account its own weight. As a guide, the safe working load (SWL) for an excavator is a factor of 1/3 of the tipping weight. This shall be used as a literal guide to ascertain the quantity of weight that can be lifted. The weight that an excavator can lift is governed by two factors. The first being the statutory section plate or manual issued by the manufacturer. The second being the excavator’s own hydraulic capacity and hydraulic system capability. The hydraulic capacity of an excavator is best described as the rate of flow it has available for doing a particular task and this can only be interpreted from the machine’s pressure and flow rate. If the rate of flow for a machine is not known, the pressure can be checked by two attachments at the same time, by operating them and observing the carriage motion. A slow motion of the attachment indicates that there is not much flow rate spare.

8.2. Load Securing and Stability

This is to ensure that you understand how important it is to correctly secure any load, as failure to do this is a major cause of excavator overturning. The load is a label put on the bucket or attachment to show the weight of the item. Often materials will be loaded into transport containers such as lorries or skips, so it is important to know the weight of the item before it was loaded. The best way to avoid tipping the machine is to keep the load as low as possible, as the higher it is the less stable the machine becomes. When using a bucket to carry materials, it is good practice to angle the bucket to the slope of the material, as then the load will be evenly distributed as possible, and will make the machine more stable. The factor of load mass can be seriously dangerous, particularly when digging with buckets on grades or while loading and excavating on truck loading ramps. The stability of the machine is constantly changing with height and the swing of the superstructure, and it is common to have the machine go over top dead center if a large mass is dug out on the upslope side. Here is a checklist you can use to determine whether the load is properly secured and the machine is stable.

8.3. Weight Distribution and Calculation

The main consideration when excavating is the weight of the material being handled, the weight of the material will affect which excavation equipment is more suitable. There are two factors in weight to consider, the first is the weight of the material per volume, and the second is the total weight to be shifted. Excavators and backhoes are designed to work in a trench while having their tracks on a firm surface, with the material to be excavated being no more than 75% of the maximum lift for the machine. This is because the bucket has a pivot point and an increase in load being lifted on a slope with the pivot being the center will act as a lever and increase the load on the machine and decrease stability. Lengthy reach work is often done on wheeled machines for this same purpose. It is also imperative that the area surrounding the trench/s are kept as clear and level as possible to prevent risk of injury and maximize the machine’s performance. Excavation is a process that involves digging and removing dirt, rock or other materials from the ground. This is a complex and risky process that requires the correct equipment in order to be done efficiently and safely, especially considering the advancement of excavation technology. With such a wide range of excavation equipment available, identifying the right machine for the job is the first step to increasing safety, productivity and cost efficiency. Ideally, the correct machine would be the one that can transfer the weight of the material to be moved, a.k.a the “load” in the most efficient way possible. When considering small scale home/DIY excavation, this load would be literal in the sense of a load in a trailer. However, load is a term that can refer to a part of a larger volume of material e.g. liquid in the tank of a lorry and is also used in engineering equations for statics and dynamics of forces on materials. These forces and the machine itself must also be reconciled with the stability and mobility of the machine. This article will discuss applying statics to machines to optimize their stability and mobility in relation to the forces of the work they do.

9. Excavator Environmental Considerations

Various national guidelines require erosion risk management plans to be put into effect for construction sites of differing size. The basic principles involve identification of areas most at risk from erosion, usually those with little vegetation, steep slopes, or easily eroded soil types, and taking action to either avoid these areas or carry out work in a way that will not worsen the level of erosion. Measures will often involve planting vegetation and the installation of barriers to prevent movement of both soil and water. In situations involving extensive excavation, it might be decided that the erosion risk is too high and that the area can only be worked on in dry weather.

Reduction and prevention of soil compaction can be achieved using a variety of methods. In the planning phase of the project, consideration can be given to the most suitable areas and timing for use of heavy machinery; areas with wet, soft, or sandy soil are best avoided as these are most prone to compaction. Where construction throughout all areas is unavoidable, consideration can be given to soil reinforcement with the use of boards or matting. Excavation work should be carried out methodically with the use of the machine’s tracks minimized and regular passageways left to provide access across the site.

Soil is a fundamental resource, and it is essential to plan operations to avoid adverse effects on its health and viability. However, often soil is compacted, which reduces its permeability; compaction also makes the soil less able to support plant life and more prone to erosion. Typically, soil will be compacted by the movement of tracked vehicles and, in particular, an excavator working in a single area for a prolonged period.

Environmental impact should be a significant consideration when planning operations with an excavator. Preservation of the working area in a condition that is suitable for future land use should be a priority. This will involve consideration of soil stability, minimizing compaction, dust and erosion, and appropriate clean-up of the working area. When operating an excavator, consideration should be given to minimizing the levels of noise and dust generation. This is particularly relevant if working in close proximity to other businesses or residential areas. Fuel efficiency and minimizing energy use are additional key considerations to reduce the environmental impact of using an excavator.

9.1. Soil Protection and Erosion Control

Soil is a non-renewable resource and its protection is important for future land use. Given the nature of an excavation, soil can become unstable leading to erosion. Soil erosion occurs naturally but can be accelerated by the movement of plant cover and the removal of vegetation – both likely outcomes of site clearance. Great care must be taken on steep land, particularly if the subsoil is near the surface. The provision of an adequate soil protection and erosion control plan is often a prerequisite to obtaining planning permission. It is well recognised that the best way to protect the soil is to prevent erosion occurring. Any form of erosion control is only a remedial treatment and it is unlikely that revegetation will ever fully restore the original plant community and stabilize the soil.

9.2. Noise and Dust Management

Noise and dust nuisance has to be prevented to safeguard the local environment and the health of the people and wildlife in the vicinity. Measures to prevent noise and dust are often readily integrated with other site activities. For example, earth bunds built as noise barriers can also serve to screen the site and safety reduce the visual impact of the project. The use of recycled aggregates and building materials that are longer lasting, biodegradable, and less prone to dust emitting can provide a simple means to reducing the environmental impact of construction activity.

Once work has started, noise and dust emissions from construction sites can cause problems for the environment and local communities. Noise can be a problem for people living near construction sites. It is a hazard to the people working on the site and to others in the vicinity, and it can also disturb wildlife. Dust from construction activities can have serious consequences for the environment and the health of local residents. Dust can land on leaves and hinder their ability to photosynthesize, it can dirty water supplies, and it can affect air quality.

9.3. Fuel and Energy Efficiency

The basic issue of fuel and energy efficiency with a mechanical excavator results in its design. All modern excavators are powered by hydraulic fluid. However, the type of hydraulic system and the way an excavator uses hydraulic energy can significantly affect fuel consumption. The mechanical/hydraulic excavators out there at the moment can be split into two main types – those that use a hydraulic energy recovery system and those that use engine power to drive the hydraulics. Energy recovery systems save fuel by using gravity to move the arm and bucket, and then recovering the hydraulic energy once these are loaded and need to be lifted. Tests in the UK have shown this type of excavator to save over 35% on fuel when digging and over 20% in loading and truck loading operations. Standard excavators use engine power to pump hydraulic fluid at a constant rate, even if the movements being made do not require the full flow of oil. This system is very fuel-intensive as the engine is often required to work at maximum performance. A modified control system has been designed to vary the hydraulic flow to meet the demands of the work. This type of system has been found to reduce fuel consumption by up to 20% when compared to a standard unit and is now mandatory for all new excavators entering the “Image II” energy star compliance program in the USA.

10. Excavator Emergency Procedures

In the event of an emergency, it’s important to remain calm and take appropriate action. The first module of emergency procedures covers fire safety and how to use a fire extinguisher. Fire is a serious risk when diesel and other flammable materials are present on a construction site. The main causes of fire are discarded cigarettes, electrical faults, and leaking fuel. Precautions that should be taken are to have a fire assembly point, adequate fire fighting equipment, and fuel stored away from machinery and plant. Should a fire occur, the operator should stop the machine engine and move away from the source of the fire. Depending on the severity of the fire and the operators’ judgment, the fire could be tackled by a nearby fire crew or the machine could be operated away from the fire to safety. Only if safe to do so, and if there is minimal risk of the machine overturning, should roll over protective structures (ROPS) be used to provide additional safety to the operator. The fire should be approached from upwind to prevent smoke and fumes blowing into the operator’s face. If the fire becomes uncontrollable, the operator should leave the vicinity and alert site personnel. During this procedure, the fire should not be allowed to come between the operator and his escape route. An additional safety measure to prevent potential vehicle fires is to develop an escape plan and keep pathways clear of obstacles. This will enable quick and easy evacuation in the event of a fire. Regular fire drills with site personnel can also be beneficial to ensure everyone knows exactly what to do in the event of a fire. It is a legal requirement for all employers under the Health and Safety (First Aid) regulations 1981 to provide adequate equipment, facilities, and personnel to ensure their employees receive immediate attention if they are injured or taken ill at work. (HSE: Approved Code of Practice L74 para 214). Module two will only cover first aid relevant to the operator; however, it is important to remember that every operator should know the location of first aid facilities and how to contact the appointed first aider. The main causes of fire are discarded cigarettes, electrical faults, and leaking fuel. Precautions that should be taken are to have a fire assembly point, adequate fire fighting equipment, and fuel stored away from machinery and plant. Should a fire occur, the operator should stop the machine engine and move away from the source of the fire. Depending on the severity of the fire and the operators’ judgment, the fire could be tackled by a nearby fire crew or the machine could be operated away from the fire to safety. Only if safe to do so, and if there is minimal risk of the machine overturning, should roll over protective structures (ROPS) be used to provide additional safety to the operator. The fire should be approached from upwind to prevent smoke and fumes blowing into the operator’s face. If the fire becomes uncontrollable, the operator should leave the vicinity and alert site personnel. During this procedure, the fire should not be allowed to come between the operator and his escape route. An additional safety measure to prevent potential vehicle fires is to develop an escape plan and keep pathways clear of obstacles. This will enable quick and easy evacuation in the event of a fire. Regular fire drills with site personnel can also be beneficial to ensure everyone knows exactly what to do in the event of a fire.

10.1. Fire Safety and Extinguisher Use

Fires on construction sites can pose a significant risk to safety. Because most fires start in the vicinity where work is being carried out, there is a risk of fire occurring on or near a vehicle, including in the cab. Operators and other site workers should be aware of the causes of fires and the means of preventing them. In the case of a fire in or around the machine, the operator should, if possible, move the machine to a clear and safe location before dismounting to tackle the fire. Where the operator judges it to be a small fire and it is safe to do so, the fire extinguisher on the machine can be used to put it out. Under no circumstances should the operator put themselves at risk from a fire, as the loss of a machine is far less significant than personal injury. All operators and site workers should be trained in the selection and use of the most appropriate fire extinguisher that is suitable for the types of fire that are likely to occur, and to the method of training available. This allows them to use the most effective fire-fighting tool for the job, in the safest and most efficient manner. An understanding of fire types and the suitability of different extinguishers is important. Only tackle a fire if it is safe to do so, and raise the alarm for larger fires and fires of unknown origin. Personal safety should always take priority over machine or site safety.

10.2. Evacuation and First Aid

If there is a point during the course when the operator feels unwell and unable to continue, they must inform the instructor immediately and return to the centre. There are welfare facilities and the instructor or director can make provision for transportation to seek medical assistance. If first aid is required at any time during the course, treatment will be given by the designated first aider who will be one of the staff at the centre. A first aid box is available on site in the machine shop. In the event of a serious incident, the emergency services shall be called (dial 999 ask for ambulance) and the location for emergency vehicles is the yellow gate on the main road to Stow. The centre director must be informed of any incidents or accidents involving injury or damage, as soon as is practical. A record of such reported incidents will be made and filed by the course administrator. All incidents will be investigated and efforts made to avoid similar occurrences in the future. Any lessons learnt from incidents or accidents will be communicated to staff and/or students.

10.3. Reporting Incidents and Accidents

In reality, things do go wrong, and when it does, it is important that the incident or accident is reported effectively. This would enable the company to implement the correct control measure to prevent a reoccurrence and also ensure that equipment is safe to use. To report an incident effectively, one must have an understanding of what an accident or incident is. An accident is an undesired event that results in harm to people, damage to equipment or structures, or loss of money. Incidents are undesired events that under different circumstances could have resulted in an accident. All accidents and certain incidents that occur on a construction site must be recorded in the company’s accident book. This information will then be used to complete form F2508 for reportable accidents. All information on individuals is confidential and cannot be disclosed on the form. The form is then sent to the Incident Contact Centre in the event of a reportable accident or a member of the public involved in an accident. The completion of this form fulfills the employer’s obligations under RIDDOR.