Earthing of MEMUs
Tanks, bulk containers and special compartments for packages of explosives made of metal or of
plastics material shall be linked to the chassis by means of at least one good electrical
connection. Any metal contact capable of causing electro-chemical corrosion or reacting with the
dangerous goods carried in the tanks and bulk containers shall be avoided.
Stability of MEMUs
The overall width of the groundlevel
bearing surface (distance between the outer points of contact
with the ground of the righthand
tyre and the lefthand
tyre of the same axle) shall be at least equal to
90% of the height of the centre of gravity of the laden vehicle. In an articulated vehicle the mass on
the axles of the load-carrying unit of the laden semi-trailer shall not exceed 60% of the nominal total
laden mass of the complete articulated vehicle.
Rear protection of MEMUs
A bumper sufficiently resistant to rear impact shall be fitted over the full width of the tank at the rear
of the vehicle. There shall be a clearance of at least 100 mm between the rear wall of the tank and the
rear of the bumper (this clearance being measured from the rearmost point of the tank wall or from
protecting fittings or accessories in contact with the substance being carried). Vehicles with a tilting
shell with rear discharge do not require a bumper if the rear fittings of the shell are provided with a
means of protection which protects the shell in the same way as a bumper.
NOTE: This provision does not apply to MEMUs where the tanks are protected adequately against
rear impact by other means, e.g. machinery or piping not containing dangerous goods.
Combustion heaters shall meet the requirements of 18.104.22.168.1, 22.214.171.124.2, 126.96.36.199.5, 188.8.131.52.6 and the
(a) the switch may be installed outside the driver's cab;
(b) the device shall be switched off from outside the MEMU compartment; and
(c) it is not necessary to prove that the heat exchanger is resistant to the reduced afterrunning
No fuel tanks, power sources, combustion air or heating air intakes as well as exhaust tube outlets
required for the operation of the combustion heater shall be installed in the load compartments
containing tanks. It shall be ensured that the heating air outlet cannot be blocked. The temperature to
which any equipment is heated shall not exceed 50 ºC. Heating devices installed inside the
compartments shall be designed so as to prevent the ignition of any explosive atmosphere under
Additional safety requirements
MEMUs shall be equipped with automatic fire extinguisher systems for the engine compartment.
Protection of the load by metal thermal shields against tyre fire shall be provided.
Additional security requirements
Process equipment and special compartments in MEMUs shall be fitted with locks.