1. Introduction

The course will cover an introduction to the mechanical and hydraulic systems of the roller, the importance of risk assessment, identifying and preventing specific roller safety issues, and a roller operating theory. The course will then test the basic skill level of the candidate regarding the identified components of the training course. The training is very much a hands-on experience, we will put the candidate in the driving seat and teach through practical scenarios. At the end of the course, we run a theory and practical test to ensure that the candidate is fully competent and safe at operating a ride-on roller. Once the candidate has passed this test, he will be awarded the CPCS red trained operator card.

You should know that rollers are versatile machines in that they are used extensively on construction sites for a variety of compaction purposes ranging from highway construction to landfill waste site compaction. There are many types of roller – the most common is the ride-on roller. The training and testing standards are aimed at all ride-on rollers.

This course is aimed at anyone who uses or will be using ride-on rollers. You are a person who: What does the course cover?

1.1. Course Overview

To enable the candidate to: – Be aware of the needs of those who might be affected by their work – Know what checks to make on the roller and its ancillary equipment – Be able to locate and identify the major components of the roller and explain their functions – Be able to use the operator’s manual to obtain the manufacturer’s information – Explain the meaning of the various instruments on the roller – Start and stop the roller in a safe manner

The aim of the NPORS Ride on Roller Training course is to provide the candidate with the basic knowledge and practical skills involved in operating a ride-on roller in a safe working manner. In addition to the above, this training will include information on the construction training skills scheme.

Course overview: CPCS A31 Ride-on Roller training is primarily for those in the construction and civil engineering industries operating ride-on rollers. The NPORS operator card is also well recognized in these sectors.

1.2. Importance of Ride-on Roller Training

Other findings from reports have suggested that a lot of construction employers are under the impression that the training and familiarization their workers had with smaller road-going vehicles is transferable to the larger, more complex ride-on roller. This is not the case; the movements and functions of these larger machines differ considerably. By attending an accredited training course, the operative will be able to understand what is required to operate the machine safely and to correctly apply the best practices. This is fully backed up by legal requirements; with the introduction of the new CDM regs, the duty of care for employees’ safety has now been firmly placed on the shoulders of their employers. By law, an employee needs to be trained and competent for the task he is doing. It is in the employers’ legal interest to provide workers with the opportunity to obtain training, which should be repeated at suitable intervals and at least every five years.

The importance of attending a CPCS A31 Ride-on Roller Training Course cannot be overlooked. The number of individuals who are seriously injured or killed in construction work is yet again too high, and the number of roller accidents seems to be on the increase. Statistics from 1999-2003 show that there were 5 deaths and 35 major injuries caused by a roller in a construction environment. It has been proven in many cases from accident investigation reports and personal witness statements that the operator had no formal training to operate the machinery.

2. Regulations and Safety

Health and safety is a key consideration for everyone in the construction and plant hire industries. A31 operators are often required to work on sites which are shared with other operatives, where the general public may still have access or in locations where other site work is still in progress. A good understanding of accepted health and safety practice in roller operations can help to avoid accidents or on-site injuries. The HSE booklet “Roll over protection – Are you protecting your workers?” gives simple practical advice for employers, supervisors, and operators on how to protect plant operators from the risk of overturning. This can be downloaded from the construction section of the HSE website. It would be wise for any roller operative to familiarize themselves with this document. Health and safety law is very important, ignorance is no defense for roller operators if they breach it. An A31 operator must also be aware that his roller will be subject to the Construction and Use Regulations of 1998. This applies to new or existing machines. These regulations are essential to satisfy health and safety requirements for work equipment, all A31 operators should have a compliant understanding of what these standards mean in operation. A summary can be found at the Provision of Work Equipment Regulations 1998, this is a more detailed document, but is useful for any roller operative to know and understand.

2.1. Health and Safety Guidelines

Smoking because dust and gas contain some toxic substances. Respiratory protective equipment should be provided by the employer on a suitable rating for the type of dust created. Also, suitable skin cleansing materials should be provided. Working with bitumen, the diesel engine of the roller should be shut off. If this isn’t possible, the roller should be moved clear of the site to prevent exposure to other workers. Insulation of hand and arm vibration should be attempted through utilizing anti-vibration mounts where practical. A workforce with low knowledge and understanding of English is common in this industry. Special training and supervision should be given to these workers to ensure they understand how to work safely. Regular cleaning of the roller is also very important because a build-up of certain substances on the roller drum can affect its performance. Finally, it is important to be aware of the dangers of working alone and at night. Guideline 1: An informative tone should be used; tell the reader how to work safely. Guideline 3: The text is focusing on providing information on how to work safely in different situations. Guideline 5: The content is coherent with the summary of the essay, reflecting the key ideas and themes, for example, the need to spread the awareness of health and safety throughout the workforce, and the importance of clearing understanding when using plant equipment.

2.2. Legal Requirements for Operating Ride-on Rollers

The main piece of legislation affecting the operation of Ride on Rollers is PUWER 98. There are some exceptions to the use of ROR. It is not covered by the Regulations where it is used in an area which is open to the public, although PUWER would still apply in this situation. ROR used in the construction of play areas only have to comply with the Essential Health and Safety Requirements of the Amusement Devices Directive, and not PUWER. ROR used in the extraction industries have no specific regulations for the machine itself, but again PUWER would apply for equipment used with the machine. Any machines manufactured after January 1st will require a certificate of conformity to ensure that they comply with all relevant European Directives. ROR that is to be used on the highway, or in construction, should comply with the Road Vehicle (Construction and Use) Regulations. If the machine is to be used solely off road, those parts of the regulations relating to the construction of the machine for use on the highway need not apply. ROR used on the highway must also comply with C and U Regulations, but there are some exceptions for machines registered before September 1986. ROR is exempt from the requirement to be fitted with a seatbelt until 1st September 2006, and also the requirement to be fitted with a roll over protection structure until September 2007. This is due to there being no suitable ROPS available for ROR at the present time. ROR is also exempt from the requirement to use a flashing amber direction light.

2.3. Personal Protective Equipment (PPE)

You may need to wear the following PPE: – High visibility clothing. If it is a reversible garment waterproof on one side, make sure it is orange on one side. – Safety helmet – Steel toecap boots – Ear defenders – Work with bitumen or hot lime materials will require additional specific PPE, e.g. gauntlets and/or face protector.

If it is wet in the morning, then you must put it on something warm to allow it to dry out. Don’t leave it overnight in your cab.

If you are in any doubt over whether an item of PPE is suitable for purpose, show it to the tester for advice.

You must know what the following phrases mean: – Suitable for purpose – Maintained in good condition

It is a legal requirement to wear PPE on construction sites. This must be observed during both training and testing. PPE must be suitable for purpose and manufactured to a proper standard. It must be maintained in good condition, and any loss of performance which could affect safety must be reported and the PPE replaced.

Full description graphic

3. Ride-on Roller Basics

Any set of given compaction works will have a specified level of compaction that it will have to reach. This is usually given in terms of a compaction standard. Today, there is a realization across the construction industry of the importance to measure the compaction levels on the works. This is solved by complex and time-consuming plate tests and core samples. An easier method is to have a specified density to achieve at the surface level. This could be any one of a number of tests using a nuclear densometer, but the simplest test is by using a surface moisture/density test.

Rollers are also used at landfills or in agriculture. In landfills or agriculture, as for road compactors, materials are usually compacted in at least two layers. A sheepsfoot roller is used in landfill compaction. The roller has a drum at the back with many protrusions. There are types of rollers that are generally used in agriculture or for a specific type of road. These are a grid roller or a pad foot, and a tire roller or a smooth roller. This machine has become an essential tool in enabling a good finish to road structures, as the first road rollers, and is used widely throughout the world. This has led to an unquantifiable increase in the quality and durability of highways and motorways throughout society.

The ride-on roller functions in much the same manner as a large, motorized, land-based vehicle. It is a vehicle used to compact surfaces, such as roads. The material the ride-on roller is used to compact may be loose or in a cold state.

3.1. Understanding the Ride-on Roller

Now that we are familiar with the different types of rollers and what they are used for, we need to understand just a little more about how a roller actually works. Before a roller can be used for its main job on a construction site, the roller has to first break down the surface to be rolled, ready for the first part of the rolling process. This is known as the kneading stage. During this stage, the main objective is for the drum or drums to generate enough force to break down the material and mix it into itself. Once this task has been completed, the roller can now continue to crush the material until it has reached a specific dry density value. This is typically a value that the material can’t withstand and is more than satisfactory for the final rolling to take place. The final stage is the shearing or the rolling stage, which is what rollers are usually used for. This part involves the aggregate or the material gradually breaking into smaller pieces, moving and mixing together, and forcing water out of it. Rollers will use vibration, frequency, amplitude, and roller speed to ensure that this happens. This is a simple explanation of how rolling works. Each different type of roller will achieve this in different ways, and each will be suited differently depending on what type of material and the size of the project. Step is to know how a roller achieves these tasks. This will involve identifying the aggressive technique, which will usually involve high frequency and high amplitude.

3.2. Components and Controls

The ride-on roller being checked is a Bomag BW120 2. This machine is fitted with two smooth steel drums and a vibration function. Drum steering is a result of the drive to one drum being disengaged, allowing the drum to turn independently. This is accomplished by a pedal and requires maximum engine revolutions. Turning of the machine is done by use of the steering wheel, which turns the front drum. Therefore, the roller will turn in the direction the wheel is turned. The vibration function is a switch to the left-hand side of the seat, which requires the engine to be at maximum revs and the left drum to be disengaged from the hydraulic system. Always refer to the manufacturer’s operating instructions for correct controls information on each type of roller.

A roller is a machine used for compacting surfaces during sub-base and asphalt compaction, so fewer rolling passes are required, resulting in an extremely durable surface. Normally, it is constructed with a steel drum, with one more recently manufactured with a rubber-coated drum. Some rollers are equipped with a vibration function for increased compaction output.

In order to prepare the ride-on roller for checking, the candidate must understand the various components and controls on the machine. These hydraulic controls are used for loading and unloading the machine on and off a trailer. The vibration controls are also required, so the candidate must understand the process and procedure of engaging and disengaging these functions. If function controls are used while performing checks, the machine may become operational, which could be a danger to the candidate.

3.3. Pre-Operational Checks

1) Locate and read the roller handbook and understand recommended safety and operating procedures. 2) Ensure all pre-operational checks are carried out methodically and are appropriate for the roller. 3) Complete all maintenance and repair highlighted from the operator and/or site maintenance person. 4) The roller is to be parked on level ground, and the roller is to be switched off with the key removed. The parking brake should be on, and the drums must be chocked. The roller should be isolated from any external power source or other plant that it may be tandem towed with. 5) Visual checks: Confirm all guards and ROPS system are securely in place, all tires are correctly inflated according to manufacturer’s specifications and rated to carry the load. 6) The roller should be clean of any fluid spillage or rubbish. Don’t forget to clean the air intake for the engine and the radiator. 7) Assess the amount of fuel required for the job and top up from a suitable portable container to reduce the chance of spillage. 8) The last check to be performed before the roller is moved for operation is the daily fluid leak inspection. Look for fresh fluid leaks on the ground and trace them back to identify the origin. Any leaks must be repaired before the roller is used.

8 Point Pre-Operational Check.

4. Operating Techniques

To start a roller, the roller should be set up in the required plant, with all safety checks carried out. Check under the drum and at the rear of the roller to ensure there are no personnel in these areas. Start the HAV’s assessment by checking the vibration levels in the handles, then smooth out any rough welding in the handle or drum steering handle with a grinder to reduce excessive vibration. When using a pad-foot drum, ensure that the pads are unbolted and the shell should be fitted with a bung and chain. Engage the roller vibration and ensure that it is working within safe levels, i.e. the handle only vibrating as much as necessary to move the roller and no severe vibration in the operator’s seat. This will reduce the possibility of white finger symptoms. Always use an operating technique that results in minimum acceleration of the drum to prevent excessive wear to the drum and the roller to prevent costly repairs. It is essential to get off the roller and check the site or ground conditions before the job commences. This will enable you to determine the drum offset required and if the site is suitable for the roller in use. Always keep in mind the speed that is safer for the roller to ascend or descend slopes than to operate on them. A 3-point stance or both side-to-side and uphill and downhill grip with firm footing must always be maintained. When working on a slope, scarify across the slope and compact with the slope. When driving forwards in a straight line, tip the back and slowly accelerate until the required speed is reached. This will reduce any slippage. Using the brakes to over-acceleration and sudden stops will deter tearing and always vibrate when the roller is in motion. This will ensure that the maximum compaction is achieved.

4.1. Starting and Stopping the Ride-on Roller

To stop a ride-on roller in the event of an emergency, the first step is to turn off the vibration system. Failure to turn off the vibration system may result in loss of control during braking. With the roller still moving, steer it to a level area clear of other workers, equipment and obstructions. Stop the roller and engage the parking brake. Turn off the propel motor and vibration system. Lower the implement to increase stability, then turn off the engine and exit the operator’s station.

To start a ride-on roller: – The roller should be equipped with a ROPS cab. The ROPS cab should be mounted in the raised position. – Fasten the seat belt. – Lower the water spray system or scraper bar to ensure good traction. – Start the engine. – Activate the vibration system. – Release the parking brake. – Engage the propel lever(s). – Proceed with vibration system turned off.

4.2. Steering and Maneuvering

During normal operation, vibration should be used. The front drum should be the vibrating drum unless otherwise stated by manufacturers. When the machine is moving with vibration on or when it is static and vibrating, it is tracking straight. When the machine is static and the vibration is turned off, the front drum will move to its central, offset position (due to power and vibration being isolated from front to back on all modern machines). Steer the front drum to the desired amount of offset, then start to vibrate. When the front drum is tracking and vibrating straight as described above, the machine will travel in a straight line. If a turn is required, the operator should stop the machine in a suitable location and turn the vibration off. Then turn the steering wheel to the desired position for the amount of turn required and engage the vibe again. The closer the handle is to the full lock position during a turn or change in direction, the smaller the turning circle will be. Always turn the handle in the desired direction before the drums start to move. Try to limit drum movement without vibration below the RPM where the vibration is effective. This will save fuel and drum wear. When turning off the vibration on completion of the turn, the handle should be placed back to the straight position for tracking. This will re-center the offset drum to its central position ready for the next application of vibration.

4.3. Operating on Different Terrains

Where the slope exceeds that which the machine can safely travel up and down, it will be necessary to work across the slope. In this situation, it may be necessary to use an A41D or A42D Forward Tipping Dumper to tow the roller using a roped towing hitch. The roller operator shall be towed up and down the slope, making alternate passes in each direction. The towing dumper shall move across the hill, towing the roller which will eventually fill in and make a level area of ground. This method is essential in creating a safe platform for machine travel and still has the same safe principles of working straight up and down the slope. When using dumper towing the roller, it is important to remember that the dumper must always travel downhill.

When operating the roller on any type of sloping ground, it is always best to travel straight up and down the slope. If you try to travel across the slope, the risk of machine and load overturning is increased. Always try to compact across the slope with an even number of passes in each direction.

5. Compaction Principles

There are several factors that affect the degree of compaction to be obtained. It is important to identify the nature of the material to be compacted before beginning the process and employ the correct technique for that material. The most effective method for determining the nature of a soil is a proctor test. This test will determine the optimum moisture content for the soil and, in turn, the maximum dry density. This is important as the mechanical force of compaction is the same regardless of the moisture content, but the density obtained is highly dependent on the moisture content. High moisture content reduces the internal friction of the soil and can cause it to become liquid-like. The soil is then said to be in a “modified state”. A slippage or distortion of the soil shape is likely if compaction is attempted at this point. A highly cohesive soil or clay may stick to the roller drum and cause a build-up until the drum becomes smooth. The rolling method should not be used in this case as a smooth drum will have low effectiveness in expelling air from the soil. Drum type and weight are also factors in effective compaction. High weight combined with static force is effective on sand and gravel, but a high weight combined with a kneading motion is desired for cohesive soils. Step-by-step equipment guides are provided for each machine in the CPCS study pack. A change in the compaction procedure can be done as the soil changes between lifts or layers. A layer of the material should be compacted until no further change in its density occurs. Any more compaction will have no effect on density and can actually cause a forceful expulsion of air leading to a decreased density. This will cause an uneven increase in density at the material surface.

Compaction is the process of expelling entrained air from the material being compacted and reducing voids in the material, thereby increasing the material density. Compaction is essential in the construction of roads and embankments and is a factor in building settlement. The effectiveness of a material in terms of its serviceability for its intended task is highly dependent upon its density. A well-compacted material is capable of transmitting stress through its mass. The ability of a material to do this is dependent on how density is an even stress distribution in the material. Greater density promotes a more even stress distribution. Compaction can be done in several methods such as kneading, impact, rolling, and pressure. Kneading is a process of compaction that is applied to cohesive soils and is effective in expelling air from the soil. It is done by literally squeezing the air out of the soil. Impact is often used in compaction of dry and coarse soils. The object is to jar the soil and cause the individual particles to move into a denser configuration. Rolling is the most common method of compaction. Often with the use of a CPCS ride-on roller course. This method is effective for many different types of soil as the type of roller and method of rolling can be varied to suit the type of soil. Pressure is used in compaction of an asphalt concrete surface. The compaction of bituminous materials is highly dependent on temperature. High air and low humidity conditions are ideal for compaction as when bitumen cools it loses its fluidity.

5.1. Importance of Compaction

The more heavily a material is loaded, the more it is compressed. The more a material is compressed, the higher the load it can support without deforming. A part of the load is transformed into potential energy and then into kinetic energy. The aim of compaction is to minimise the volume of air in the mix and to get maximum density with the mix of aggregate. If there were no air or voids in the material. This water is in the form of a thin film round the particles of aggregate and when fully compacted, most excess water should have been removed, and any that remains should just be sufficient to lubricate the particles and fill the voids. The strength of a mix is not only reflected in the compaction level, but also in the moisture content. High levels of compaction are easier to achieve with a mix of a reasonably high workability and this can often be reached with the addition of the correct type of admixture. For example, plasticisers. Static steel wheel rollers have a very heavy drum and this makes them suitable for compacting coarse-grained materials and pads to fill voids between particles. They are not so effective on soft materials, which frequently become compacted whilst the roller is turning and this can lead to their sticking to the roller drum and subsequent surface tearing. Vibrating rollers are very effective on all materials and in addition to the gyratory motion generated by the machine, which propels it forward, vibrations from the drum contributing to the materials movement are also decisive in the efficiency of the roller. Sand, gravel and crushed stone are commonly vibrated with the depth of compaction being controlled by the amplitude and frequency of the vibration. The final type of compactor mentioned in the CPCS module is the pneumatic-tired roller mainly used for sealing and thin layered compaction. High contact pressure is applied and there is a kneading action, pushing the bitumen to the surface allowing excess to be easily removed.

5.2. Factors Affecting Compaction

Factors affecting the degree of compaction are described here. They should be reviewed as changes in any one of the factors may affect the desired level of compaction. Influences are described which affect the target level of compaction such as specifications and tolerances, and the type and expected performance of the constructed structure. Changes in the height of fill lift used or in rollers and rolling patterns adopted can be changes in compaction technique rather than problems in achieving compaction. Such changes can be desirable when it is possible to improve the level of compaction for heavy compaction plant or the achievement of specified compaction for light. They would be caused by a judgment that it is possible to improve the system efficiency or effectiveness. Because of those factors affecting the degree of compaction that can change the compaction technique, it is necessary to allow the reverse exchange of information between the level of compaction already achieved and technique used. This is particularly important in applied research and must be based on the firm understanding of cause and effect in compaction.

5.3. Compaction Techniques

Rolling in the longitudinal and transverse directions: • In general, breakdown rollers are utilized with the aim of achieving high levels of compaction and density. These are normally static steel-wheeled rollers, which are the width of the paved wearing course, and due to their high axle loadings provide high levels of surface pressure. • Firstly, driving/rolling in the longitudinal direction should be carried out, laying the most practical amount of passes that does not induce shoving. Shoving is identified by the roller lift of the rear wheels causing differing amounts of aggregate particles to ‘settle and move’. There is a high possibility of forming a wave pattern. This happens because the asphalt becomes too stiff to allow the passage of the roller to push the aggregate particles down into the semi-solid mix, and instead the roller only achieves smoothing the asphalt surface layer which moves the mix in front and off to the sides. This method delays further smoothing and trapping of air voids until the next hot day when the mix becomes more pliable sticky. • With heating of the mix and possibly the use of a breakdown compound, the roller work can be crowned finished, providing there is adequate control of trying to achieve a uniform lift thickness. At this point of compaction, the mix should only be a matrix of only just enough electrically charged aggregate particles. Sinking the roller drum any more will cause flushing and/or picking. Compensation can be sometimes made for undercompaction in the next lift. • Once as much as possible has been achieved in the way of mix particle displacement without flattening or getting pick up of the stuck mix, the next stage involves compaction/density increase using a roller of higher surface pressure. Often the difference between a static roller and a vibratory roller is applied here with the latter producing greater compactivity effect due to the mass of the machine. This method can be continued until the higher compactive efforts produce only limited amounts of aggregate particle displacement without any further sinking or shoving. • Throughout the use of high-pressure work, aggregate particles will become stuck together and the mix will ‘melt’ becoming very sticky. High bitumen movement and possible mix shoving can cause rolling up of the mix in front of the roller drum. This is undesirable and sometimes the only way to remedy the situation at this stage is to chisel the drum and clean it constantly.

There are four main techniques of achieving the desired compaction and density of the HMA. The first two, rolling in the longitudinal and transverse directions, are aimed at achieving a certain coverage/overlap with each pass. The other two, the use of rollers with different characteristics (size, weight, drive) and the use of tensioned three-wheeled rollers, are aimed at achieving different levels of compaction/density in the pavement layer.

6. Maintenance and Inspection

6.1. Daily Maintenance Tasks Keep the water spray system functional, ensuring it cools the drums correctly and has nozzles angled in the correct position. Grease the sprinkler pump shaft at the end of each day. Visually inspect the water spray system for hydraulic leaks to conserve water usage. Leaks on the hydraulic system are indicated by a pinky oil substance around a fitting or a component. Check the water level in the battery. Top up with de-ionized water. Check the air filter indicator (where fitted) daily and change the filter element when it is in the red or when the work environment is excessively dusty, change the filter element every 5 days. 6.1. Regular Inspection Procedures Ensure that the operator completes the daily maintenance tasks (6.1). Clean the machine of excessive dirt and debris. Check the hydraulic oil, engine oil, coolant levels, and drain water from the fuel filter daily before starting the engine to ensure contaminated fuel does not enter the system. Drain water and/or contamination from the air tanks, check automatic water drains daily. Check all tires for correct pressure and damage. Weekly Clean the fuel tank cap and the area around it before removing to prevent contamination from entering the tank. Check the rollers’ vibration bands for wear. Note any smooth flat areas across the complete surface of either band as this is an indication that the roller has been static and turning on full vibration for excessive periods of time. Remove and clean the hydraulic tank breather filter. Change the engine oil and filter and fuel filter. Fortnightly Change the hydraulic and water system filters and inspect the condition of the hydraulic oil. Water system hydraulic oil is indicated by a bluey milky substance. If detected, change the oil immediately and contact your employer. Monthly Inspect the condition of all cylinders for oil leaks through shaft seals. Any detected leaks must be repaired at the earliest possible convenience to prevent water and contaminants from entering the hydraulic system. Inspect the cooling system hoses and connections. Every 6 months Inspect the alternator brushes and slip rings. Inspect the battery for security and the condition of its fixing and the condition of its vent tube. Check the battery acid level. WARNING – Battery acid is extremely harmful to skin and eyes. Take appropriate precautions and have on-site first aid measures available during this task. 6.3. Troubleshooting Common Issues The following troubleshooting table should be used in conjunction with the machine’s operators and engine manuals. All procedures outlined require the machine to be turned off and the isolator switch removed, unless specified otherwise.

6.1. Daily Maintenance Tasks

Fuel injection pump. At regular intervals, the timing and fuel setting of the injection pump should be checked by an authorized pump repair agent. This normally should only be necessary after 3000 hours of operation.

Fuel filter. Drain off any water and sediment that may have collected in the fuel filter. Do this by opening the sediment drain valve at the bottom of the filter until clean fuel is seen to flow out, around 1/2 pint. This should be done at regular intervals and particularly during the winter months. The filter itself should be renewed every 1000 hours.

Engine oil level. Stop the engine and check the oil level using the dipstick. Top up if necessary with oil to the correct mark on the dipstick. Ensure that the dipstick and filler cap are replaced, and the oil filler aperture is kept clean. Old or contaminated oil must be drained and safely disposed of at regular intervals, and a new oil filter should be fitted every 500 hours or 3 months, whichever is the sooner.

Diesel engine and hydraulic plant. After the roller has been washed down, start the engine and while it is warming up, clean all areas of the engine and hydraulic plant to enable you to detect any leaks of fuel, oil, or hydraulic fluid. Should a leak be detected, it must be located and rectified without delay.

6.2. Regular Inspection Procedures

Service checks should be carried out in accordance with the service schedules provided at the end of this unit. These give indications as to the frequency of maintenance at a maintenance-hours level and at regular intervals. A service schedule must be prepared for each machine, and a record kept, as it provides valuable traceability information for future reference. A typical service schedule may be a document containing a list of checks that are to be carried out at 50-hour intervals, 100-hour intervals, and so on up to 500-hour intervals or even higher. A service sheet may contain a table for each category stipulating the checks to be completed and columns to record the date the work was done and the cumulative total machine hours.

Regular inspection of machinery is important as it serves as preventative maintenance to identify problems before they occur. The point of maintenance is to maintain the roller in its original condition, thus preventing deterioration. Inspection is an essential part of this, and all the checks must be recorded as they give indications as to when components need replacing or major maintenance undertaken. Regular inspection and daily checks overlap at many points. Most of the daily checks are carried out as a preliminary to the operation of the machine.

6.3. Troubleshooting Common Issues

Electrical System Problem: Engine will not crank. Possible cause: Flat battery. Remedy: Recharge the battery and check for current drain when the engine is off. If the current drain is excessive, check for component or wiring faults. Possible cause: Starter solenoid faulty. Remedy: Using a multimeter, check for power supply to the solenoid. If power is present, bridge the solenoid terminals. If the engine now cranks, the solenoid is faulty. Problem: Engine cranks but will not start. Possible cause: Water in fuel. Remedy: Drain the fuel tank and refill with clean fuel. Possible cause: Faulty stop solenoid. Remedy: Using a multimeter, check for power supply to the stop solenoid. If power is present at the solenoid, the solenoid is faulty.

Water System Problem: Low water pressure/flow. Possible cause: Water tank filter blocked. Remedy: Clean filter in clean water. Possible cause: Water valve malfunction. Remedy: Replace valve. Problem: No water flow. Possible cause: Water pump malfunction. Remedy: Using a multimeter, check for voltage at the pump when the switch is turned on. If there is voltage but no pump operation, replace the pump. Possible cause: Hose or spray bar blocked or kinked. Remedy: Remove hoses and bar and clean. Check hoses for kinks. Problem: Excessive water flow. Possible cause: Water pump stuck on. Remedy: Using a multimeter, check for power at the pump when the switch is off. If there is no power at the pump, then the control box is faulty.

7. Load Handling and Transportation

In instances when the roller has to be lifted (using a lifting appliance) into or out of positions not provided with adequate means of access and egress, the position/operation should be avoided if possible. If a decision is made to proceed, a competent appointed person will need to be involved and the lift planned as a mobile craneage operation. The machine should be fitted with suitable lifting points of sufficient strength for the purpose and with a method of sling attachment that will not cause damage. Any lifting accessories used should be of a type and capacity suitable for the operation, and all equipment should comply with the Lifting Operations and Lifting Equipment Regulations.

Where the machine is loaded and unloaded under its own power, the slope should be within the recommendations of the manufacturer and the roller should be driven on and off at right angles to the slope. In instances when petrol or diesel engined machines are loaded or unloaded from a lorry or trailer, the engine should be switched off and all the requirements of an internal combustion engine when being refueled or left parked on a slope should be followed. The machine should be started and stopped on level ground and independent of the means of access and egress to and from the lorry or trailer. Before the roller is driven on, the ramps should be of sufficient width and should ideally be provided with a non-slip surface to prevent any twisting or dislocation during machine movement.

Loading and unloading the ride-on roller with the following details:

7.1. Loading and Unloading the Ride-on Roller

When unloading and loading, it is essential that all motors are stopped and the parking brake is applied for safety.

The other method of unloading the roller is particularly useful for tracked vehicles. Use two empty roller drums, or a roller and dumper truck combination to anchor the vehicles. Chock the wheels of the loaded vehicle to stop it creeping forward. Then, with the engine running, slowly reverse the anchor vehicle(s) until the loaded equipment rolls off the vehicle body. Use mounting blocks and a basket hitch slinging technique. With certain types of vehicle, the loaded equipment can be lifted with a front end loader and the vehicle driven out from underneath. This latter method is not suitable for tandem rollers because the load must be driven onto chocks to keep it stationary.

Do not try to drive the roller off a vehicle loading ramp. This is because the gradient will probably be too steep. If the roller suddenly lurches forward, the lack of weight over the loose front drum will cause the roller to skid on the ramp. If you think that it will be safer to drive the roller off the vehicle, first build a temporary drive off ramp out of sleepers to decrease the gradient.

7.2. Securing the Roller for Transportation

There are a number of basic but necessary safety precautions to be observed in securing the roller for transportation. Features such as ROPS frames, seat belts, suspension seats, lights, and mirrors provide protection and comfort for safe traveling on public roads. They are most effective in smooth-wheeled and pad foot ride-on rollers with ROPS protection. However, they are still suitable for combination rollers where the rear is rubber-tired. The following precautions assume that the roller will be towed from the front. The most secure method for a smooth-wheeled roller is to utilize a suitable-sized plant trailer with ramps. The roller is driven onto the trailer against the resistance of the brakes through the utilization of a higher gear. The roller should be evenly spaced, allowing enough room to dismount. Once both roller drums have made contact with the plant trailer, the steering handle will still provide effective direction. At this point, the roller steering handle should be locked, and the brakes applied. Rollers that push hydraulically can have blocks placed behind the drum tires. Step 8 should then be followed. Trailers are now being developed specifically for smooth-wheeled rollers to enable towing on a single axle. This tandem tow-ball plant trailer now provides an option for a short journey.

8. Emergency Procedures

Roller Turning and Overturning/Pinch Points Movement in reverse then shifting to forward tipping on an embankment is a common cause of overturning. Be aware of this and avoid reversing unless absolutely necessary. If it is necessary, travel in reverse straight uphill and straight forward downhill. Collisions usually stem from two machines being used in close proximity. Try to ensure that there will be the only use of a machine, and if this is not possible, coordinate the movements with the driver of the other machine and be aware of where each other are on the site.

The most common emergencies using a ride-on roller are overturning and collision. Usually, these result from traveling too fast. You can avoid this type of emergency by again, following the safety procedure outlined in earlier modules. Choose rollers as opposed to wheeled machines as they provide better support and are less likely to overturn. Reduce the speed at which you use the roller on inclines and, in particular, when turning.

Virtually all accidents and emergencies involving ride-on rollers result from not following the safety procedures outlined in earlier modules. Following the correct procedure when using your machine will ensure that the risk of an accident is minimal. You can also lessen the chance of an injury occurring by employing suitable personnel in good health and suitable experience.

Your task is to consider what might happen in terms of an accident or emergency while using a ride-on roller. You should then decide what precautions can be taken to ensure the situation doesn’t arise and an effective plan to manage the situation if it does occur. Your thoughts should be recorded in both of the enclosed boxes.

8.1. Dealing with Accidents and Emergencies

The training of all personnel in first aid is of huge importance. It is something which is often overlooked in the construction industry, although most companies recognise it as a very important skill to have. Many do not actually encourage employees to take a course. Firstly, by law, there must be an appointed person on site to take control of the situation and to take care of any casualties. The appointed person is there to take charge of the first aid and emergency procedure, but it would be more beneficial for everyone to know the basic procedures and have a basic understanding of first aid. It is also important to have a means of contacting the emergency services in the quickest time possible and to have personnel who know how to give clear directions to the site. The site should have a list of emergency contacts which is visible and a way of getting in contact with the emergency services. All processes should be regularly checked and tested. If first aid equipment is stored on site, it is important that everyone knows where it is and how it can be used.

8.2. Emergency Shutdown Procedures

In emergency situations, stop the roller immediately, lower any attachments down to the ground, apply the foot brake so that the roller cannot roll freely, and then turn the engine off. Release any pressure in the attachment by operating the levers and allow all hydraulic functions to ‘drift’ as this will ensure the system is not under pressure. If the steering of the roller uses a hydrostatic drive (i.e. turn left by operating the left lever), the wheels/levers will need to be placed into the straight forward position with the engine running and then the engine switched off. This will lock the roller in the off position and the steering levers will become inactive. This is important as the roller may need to be steered away to allow access for an ambulance or other emergency vehicle to the casualty.

Before any work is carried out on or around the roller, the roller should be shutdown. If there is an attachment (i.e. a bowser or planer), the hydraulic supply should be cut off at the machine and the attachment. Also, if there is a second drum on the roller, this should be taken off so that it can be worked on in an isolated manner. Please note that isolation of the attachment or second drum will not ensure that the roller is safe to be worked on unless pressure is released from the system.

9. Practical Training and Assessment

It is advisable that training RT be delivered in line with current CITB VQ qualifications. This is not a requirement, but a recruiter with CITB approved training status will be providing training in the right move in order to improve competence and safety levels of operators working in the construction industry. This approach will lead into additional training and is a structured path to bring operators to their full competence in roller operations. The progression of training and more advanced units of VQ will allow instructors and assessors to employ marginal gains learning techniques, build competence through multiple channels, identify best practice, and correct bad habits. During on-site VQ assessments, a trainee may be able to use assessment criteria as a guidance tool in order to continue self-improvement, even if currently they have been deemed competent in an assessed task.

– Clear identification of machine and attachments and intended use. – Briefing and supervision prior to own/familiarization task.

Deliver practical training sessions replicating as far as possible the conditions of the practical test. Where facilities and a construction environment are available, it is better in the long-term to invest in training earthmoving plant and ground preparation operatives on ride-on roller specific courses. If this is not possible for novices, a large car park or other suitable even surface may be used with the instructor manipulating the machine following the instructions from a novice operator on foot who is to be practicing their signaling techniques. An instructor who already possesses proficient roller skills/knowledge and has received familiarization training may be able to effectively train a roller novice by reversing roles, and often it will be necessary for instructors to practice these roles near a construction site before their machines are even prepared for RT assessment. This is still a valid approach to training and is often an effective use of man and machine hire due to the cost of hiring and mobilizing small plant. Simulation in these scenarios is an effective tool for training and instructing. Any training simulations must always be delivered within the confines of legislation. The use of modern IT resources can also be an effective learning tool, helping familiarization and recognition of relevant good and bad practice. The full spectrum of training methods can be matched to who is receiving training, as a novice will require more familiarization and underpinning knowledge in comparison to a proficient operator who may only need:

Candidates should receive practical training sessions covering all items listed in the practical test specification. Candidates may progress from novice to proficient operator/driver on a variety of machines and attachments. Training should be given in a construction environment wherever possible. This environment will provide the best opportunity to deliver RT trainees with the underpinning knowledge and skills to then progress through their VQ’s. The construction site will also be the area where the majority of on-site assessments will take place. Any classroom-based delivery should be as a supplement to the site-based activities.

9.1. Practical Training Sessions

An area should be set aside for an operator unfamiliar with the controls and operating characteristics of that type of roller, to develop control skills in a relaxed and unpressurized environment. A series of control skills can be developed by setting out simple courses using stakes and rope or paint which simulate the situations and obstacles faced during compaction operations on site. These drills give the operator an understanding of his ability to maneuver and position the machine in a safe and efficient way.

The candidate should be given a good overall understanding of the capabilities and limitations of the roller type to be used. Routine and specific machine maintenance operations should be covered theoretically with reasons and procedures explained. The candidate should be familiarized with the instruments and controls and be able to locate and demonstrate the daily service checks and routines. This can be carried out utilizing the manufacturer’s handbook and where applicable, by a practical demonstration from the trainer.

The trainer should approach the delivery of the practical training in a way that engages the candidates. Classroom-based activity is limited to briefing sessions and discussion groups. The assessment and practical training in the safe use of a roller is best carried out on a suitable work site. The following are example programs which could be tailored to suit the needs of a particular group. These generic programs are for guidance only and may vary in contents and duration. The duration of training to acquire the requisite skill levels will vary according to the candidate.

9.2. Assessment Criteria

In order to achieve a certain unit, a trainee must fulfill all of the required underpinning knowledge and practical skills, as detailed in the logbook. If they do not meet certain criteria (e.g. due to a lack of opportunity rather than incompetence), they can still attain partial achievement. This encourages the operator to fully develop their skills and knowledge, as well as being advantageous to trainee assessment in the logbook and record of achievement.

CPCS A31 – Roller: Compulsory units are: A31 1 Prepare for work and shut down a Ride on Roller A31 2 Operate a ride-on roller to compact different materials A31 3 Comply with health and safety legislation and working practices A31 4 Move ride-on-rollers between sites by driving on to transporting units and/or towing trailers.

Assessment should take place at the end of the course as well as continually whenever the instructor sees an opportunity. This will reinforce the relevancy of the training to the operator and enable weak areas to be addressed before the test, by offering individual feedback or more training on specific tasks. If the test is the only assessment, then operators may consider certain tasks as overly theoretical and not necessary for practical operation.

Assessment criteria should be fair and consistent; meeting the skills required should result in a pass, regardless of time taken to achieve the skills. The focus of the test is the relevance of the actions to the result. The most cost effective, safest and best use of the machine will yield the highest marks. Therefore, an incorrectly executed task which achieves the right result will generally gain more marks than a well-executed task which achieves the wrong result. This approach encourages operators to develop their skills on the most relevant areas.

10. Certification and Renewal

Once the candidate has proof of any of the above, he will need to then apply for the NVQ diploma registration form and send a copy of the proof to the CPCS within 2 years of the red card expiring. If successful, the candidate will then receive a letter of endorsement to contact the CPCS to arrange a blue card upgrade.

1. A current CPCS Health and Safety test within the last two years of the red card expiry date. The candidate must achieve a pass on the CPCS Health and Safety touch screen test; this will then allow achievement of the NVQ diploma. 2. A completed relevant SVQ or NVQ Level 2 diploma. 3. Achieve a pass on the CITB Operatives Health and Safety test.

Once the candidate has successfully completed his training to the required standard on the CPCS A31 ride-on roller test, he will receive a red trained operator card. This card is valid for a period of two years. The NVQ diploma is not a requirement to obtain the red trained operator card; it is an optional route for those who would like to obtain the blue competent operator card. In order to upgrade from the red card to the blue competent operator card, the candidate will need to achieve and show proof of one of the following:

10.1. Obtaining the CPCS A31 Ride-on Roller Certification

The Construction Plant Competence Scheme (CPCS) A31 Ride on Roller card is primarily aimed at those operating ride on road rollers. As a requirement, one must first complete the CPCS theory test (touch screen) and the relevant CSCS health and safety test. However, if one currently holds a CPCS red card, gained after 1st June 2002, they will only need to complete the health and safety test as it is a requirement for those taking a CPCS technical test. The red card is considered as a legacy card and can be upgraded to a blue competence card. This can be done over a 6-year period without the need to take any further training. Although the CPCS red card is still issued until March 2017, new and existing operators are encouraged to complete modern-day training and obtain a blue operative card for the current plant categories. The route to obtaining the blue competence card will involve taking a CPCS technical test; the minimum requirement to prove practical ability in relation to the plant category. This could be achieved through experienced worker practical assessments or by attending a CPCS accredited training course with a CPCS test at the end. The test consists of a professional discussion which may be incorporated into the practical test in some instances (dependent on plant category). This is based on the CPCS log book, a series of oral questions to affirm the candidate’s plant knowledge and understanding of the manufacturers’ instructions, and finally a theory test. Overall, the technical test will ensure that candidates have the necessary competence required to perform their duties safely and efficiently on site.

10.2. Renewal Process and Requirements

For the candidates that, at the point of renewal, can provide evidence that they have registered and are working towards an NVQ/SVQ in Plant Operations (A31), the CPCS A31 renewal test will not need to be taken. However, the PIN issued for the renewed A31 competence will become invalid if the NVQ/SVQ is not completed successfully. This allows a maximum grace period of five years for clearly experienced and knowledgeable operators to then transfer this to the recognized CPCS qualification. At which point, the operator will revert back to successfully passing the CPCS A31 renewal test in order to renew. Candidates who pass the appropriate A31 renewal test will again be awarded a Red Trained Operator card. This will last for two years and can be upgraded from time constraints impeding direct progression. Step 4 illustrates the card upgrading process for A31 operators.

The renewal test will be less formal than the theory test and its purpose will be, wherever possible, to test candidates through discussion and scenario-based assessment. If necessary, this may be conducted by phone or webcam. This refreshing of relevant industry knowledge will ensure that the skills and standard of an A31 operator remain at a high level and promote continuous professional development in line with renewing CPCS competence.

To renew a CPCS A31 Ride-on Roller certification, a candidate must be successful in the CPCS A31 renewal test. The CPCS A31 theory test (1-2 hours) will consist of about 60 multiple choice questions and answers. These questions are taken randomly from a database of questions. The passing score required is 70%. The A31 renewal test will be different from the Operators/Additional Operator Theory Test taken at the beginning of a candidate’s initial practical test.