Six tonnes is an administrative boundary as much as a technical one. Below it, an excavator is compact plant; above it, the training category changes, transport becomes an organised movement, and a mistake no longer ends in bent sheet metal.
Your manufacturer’s manual prevails. This page gives the order of the steps and what changes at this size; every figure — capacities, permissible gradients, break-in duration, torques — must be read in your own manual.
1. On delivery, before you sign
- Full walk-around before signing: bonnet, rams, glazing, teeth, blade, hoses, pads or tyres.
- Data plate legible; without a serial number, no parts and no resale.
- Attachments counted, and the engine manual — a separate document, forgotten at handover, and the one that carries break-in.
- Cab structure: a cracked window can be replaced, a distorted pillar compromises the protection and cannot be repaired.
- Photographs, truck in frame.
At this mass, add one thing: ask for the machine’s logbook and documents. A site excavator lives with a history — it is what gives it value at resale, and it is what you will be asked for in an inspection.
2. Unloading
At this mass unloading is planned, not improvised. It is the operation that injures most often, and rarely the operator: the people watching.
- Firm, level, clear ground, away from the road edge and any bank.
- Nobody in the area. The first move is to clear bystanders out — not to ask them to step back a little.
- Ramps rated for the weight, clean, secured to the bed.
- No correcting your line on the ramps: come back down, line up, go again.
- Attachment tucked in and low, arm folded.
- Slow at the joint, where the centre of gravity tips over all at once.
- Slew lock engaged while driving on and off.
- Once loaded: chock and lash down, attachment resting on the bed, hydraulic pressure released.
Never jack the machine up on its boom to load or unload: manuals forbid it outright, and at this mass the machine goes over.
Many excavators in this class are also craned on. In that case only the lifting points marked by the manufacturer may be used — not a point that “looks strong enough”.
3. Before the first start
- Every fluid level, machine on level ground: engine, hydraulic, coolant.
- Find the battery isolator, the safety lever, the cab’s emergency exit and the fire extinguisher if fitted.
- Find the grease points, including those on the slew ring under the superstructure.
- Check track tension: they often travel slack.
4. First start
- In short bursts: a few seconds, a pause, crank again.
- Pre-heat in cold weather, a few seconds only.
- ⛔ Never ether, never a starting aid spray: risk of explosion.
- About five minutes at idle before manoeuvring. At this size the oil volumes are larger and warming up matters more, not less.
- While it warms: warning lights out, oil pressure, battery charge, exhaust colour, no leaks on the ground.
- First try in open space with nobody around: check the movements match the control decal in the cab. ISO or SAE, machines do not move the same way. If the decal does not match, stop.
5. Break-in
The first fifty hours are run without full revs or full loads, and the first oil change comes well before the normal interval: new parts shed metal particles the oil has to carry away.
Break-in is in the engine manual, which is a separate document from the machine’s.
6. What changes above six tonnes
- The training category changes. In France, professional use of an excavator over six tonnes falls under CACES R482 category B1, no longer category A for compact plant. Check your own national equivalent.
- The counterweight becomes the most dangerous part of the machine. It swings well beyond the tracks, at head height. You do not slew without having looked behind you.
- The working area gets cordoned off. At this size you no longer rely on people noticing you.
- Transport becomes regulated: dimensions, lashing, route. This is no longer a trailer you hitch up.
A certificate does not authorise anyone to operate: it attests competence. What authorises is the authorisation to operate issued by the employer — in France, under article R.4323-56 of the Labour Code, after a medical check and verification of knowledge.
7. Before you dig
On ground you do not know, a utility search is not an administrative formality: it is what stops you severing a service. At this size the machine will not feel a thing — not a cable, not a pipe.
Next
What makes a site excavator last: greasing kept up, the slew ring watched, track tension, and service intervals respected.