TECHNICAL RESOURCE
Technical Resource - Operating
In general, for safety reasons on work sites, excavators should only be used by fully trained operators, who are familiar with the technical and safety aspects of this type of machinery.
However, there are cases, on DIY hires for example, where this is not the case, and the hints provided on this page may be of use. These should be read in conjunction with the safety instructions provided by the manufacturer and/or hirer of the machine and are by no means intended as a full set of instructions and guidelines.
However, there are cases, on DIY hires for example, where this is not the case, and the hints provided on this page may be of use. These should be read in conjunction with the safety instructions provided by the manufacturer and/or hirer of the machine and are by no means intended as a full set of instructions and guidelines.
Basic ControlsThe basic operating controls: The digging control of a typical hydraulic excavator.
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Experienced Operator
An experienced operator at work: Loading tipper trucks with a 20 tonne excavator.
Safety note: at around 2 mins and 4 mins 40 secs the video shows potentially dangerous situations, where tipper drivers walk around the rear of the excavator counterweight, on the blindside of the operator, without hi-viz or hard hats. The principle is the same whatever the size: a 550 tonne excavator loading trucks - 50 tonnes per bucket-full. |
Safety Hints
Always observe site and machine safety rules, which should include:
- MAINTENANCE. Carry out all service checks and adjustments each day and ensure the excavator is in safe condition. (See Daily Service Checks)
- THINK! Before you start operating the excavator, whilst it is warming-up, consider the safety issues, for you, your fellow workers, and the general public.
- NEVER get off an excavator without
- Lowering bucket (and blade, where fitted) to the ground.
- Stopping engine and/or disengaging safety lever.
- NEVER work
- With you or other workers under the boom, dipper or bucket, or in the operating arc of the machine. Keep co-workers and spectators clear at all times.
- Under the excavator when it is jacked up on the arm and dozer.
- NEVER use the excavator as a crane.
- ALWAYS ensure you are aware of the location of overhead, or underground services – gas, electricity, water, drainage, and telecommunications.
- TAILSWING. Be aware that the counterweight, at the rear of your excavator, can swing out wider than your tracks. Keep co-workers and spectators out of the tail swing area.
- PASSENGERS. Do not allow anyone to ride on the machine as a passenger. On all be the very largest of excavators, there is only one seat provided – for the operator.
- CHILDREN. Do not allow children to operate the excavator.
Stability
Always remember that the stability of an excavator is variable, both in terms of dynamics and site conditions, and depends on:
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Speed
- Speed. Until you are familiar with a particular machine (or bucket/attachment) do not operate at maximum engine speed. Operate smoothly and gradually increase engine speed and power.
Digging
- Digging. For stability always try to dig over the track sprockets, in line with the tracks. On mini excavators, this will be with the dozer blade to the rear (this will also avoid damage to the blade and dipper ram), and if possible the blade should pushed down until the rear of the track is about 25mm off the ground.
- Controls. Most excavators – whatever size – have a very similar control layout for the main digging function (see videos above):
- Training: We recommend these notes are used in addition to, rather than instead of, relevant operator training.
- Up & Down: Lift is mainly* influenced by the boom ram(s), are normally controlled by pulling back (up) or pushing forward (down) the right hand joystick/lever.
- In & Out: Reach is mainly* influenced by the dipper ram, which is normally controlled by pulling back (in) or pushing forward (out) the left hand joystick/lever.
- Curl & Dump: The emptying or filling of the bucket is mainly* influenced by the bucket ram, which is controlled by pressing left (curl/fill) or pressing right (dump/empty) the right hand joystick/lever.
- Slew/Swing: To rotate the upper structure of the machine on the track frame, press the left hand control lever in the required direction; left to slew left/anti-clockwise, or right to slew right/clockwise.
- Tracking: This may be via levers and/or foot pedals in front of the operator. When the machine is facing forwards (i.e. the track drive sprockets are at the rear) the right and left tracking levers control the right and left tracks respectively. However, this stays the same, no matter which way the upper structure is slewed, and therefore takes a little getting used to!
- Other: There are other controls within the cab. On smaller machines, there is often a dozer blade, which is raised or lowered by a lever in the cab. There may also be foot pedals controlling the auxiliary (i.e. attachment) hydraulics and, in the case of smaller machines with boom offset, the swing of the arm about the upper structure of the machine. There may also be an engine throttle control, although on newer and/or larger machines, this is often computerised with options for performance modes.
- Spoil. Place spoil away from the sides of the trench, and try to keep tracks free from spoil and debris.
- Dozing. Use the dozer blade carefully and sparingly. Excessive use and deep cuts using the dozer will reduce undercarriage life.
- Attachments. The following guidelines are useful in relation to ancillary attachments.
- Size/Rating. Never use attachments that are overrated (i.e. too large or powerful) for your machine. Not only can they damage you machine (e.g. overrated hammers can bend and break dippers and rams), they can also severely destabilise the excavator, both through weight, and dynamic forces.
- Collision. Be aware that attachments may collide with parts of the machine that ordinary buckets will clear. This may include the operator cab, so operate slowly at first and pay full attention. Be particularly careful when first operating an attachment.
- Weight. Be aware that attachments may be heavier than standard buckets, although they should never exceed your machines safe working capability. If in doubt check. They may cause a decrease in stability so operate slowly at first and pay full attention. Be particularly careful when first operating an attachment.
- Work. Be aware that there are additional considerations with attachments that can pick up objects:
- It may be possible to attempt to pick up objects that are heavy enough to overload and de-stabilise the excavator. This should be avoided.
- The objects you are attempting to pick up may not be stable. Try to avoid picking up objects that may swing, slip or overbalance, as this can de-stabilise the excavator and cause danger to other site workers.
- Side Swiping. NEVER use the excavator arm to "side swipe". This can cause serious damage to both the arm and also the bucket/attachment, in extreme cases the dipper arm will be destroyed.