Vehicle Loading, Dimensions and Mass Limits for Category C
This domain tests whether you can load and operate a lorry within its legal and structural limits: mass definitions, axle loads, the harmonised dimension limits, load distribution and securing, and what happens when a weighbridge shows an overload.
Mass definitions
Kerb mass (tare) is the empty vehicle; maximum permissible mass (MMA) is the manufacturer's and legal ceiling including load, fuel and driver; payload is MMA minus kerb mass. Each axle and each axle group also has its own rating, and the train weight applies when a trailer is coupled. A legal total is worthless if one axle is over its limit.
Dimension limits
Under Directive 96/53/EC as applied in Greece: maximum width 2.55 m (2.60 m for refrigerated bodies), maximum height 4.00 m, rigid lorry length 12.00 m, articulated vehicle 16.50 m, lorry and trailer combination 18.75 m. Greek authorised mass generally goes up to 40 t on five or more axles, with lower ceilings for two, three and four-axle vehicles. Anything larger needs a special permit and marking of projections.
Load distribution and securing
The centre of gravity should be as low and as far forward over the drive axles as the axle ratings allow. Heavy items go low and evenly spread; gaps are filled or braced so the load cannot shift under braking or cornering. Securing follows EN 12195-1 practice: rated straps and chains used with anti-slip mats, lashings angled so that friction and tension both work, and a check after the first few kilometres and at every stop.
Projections and visibility
No load may obscure lamps, reflectors, the registration plate or the driver's view, and rear projections beyond the permitted overhang must be marked and, where required, permitted.
Worked example
A lorry with a 26 t MMA crosses a weighbridge: front axle 7.9 t against a 7.5 t rating, rear bogie within limits, total 26 t. Reasoning: the vehicle is not overloaded overall, but the front axle is, so it is illegal to continue. The driver shifts the load rearward or redistributes it, re-weighs, and only then proceeds; moving off with an overloaded axle risks tyre failure, steering loss and heavy penalties.
Traps that cost marks
Assuming a legal gross mass means legal axle loads; over-tightening straps until the load is crushed or the strap rating is meaningless; ignoring load shift under braking; leaving tools or equipment loose in the cab, where they become projectiles.