Air Products LH2SEMI

At a gross weight of 32,000 kg, the LH2SEMI has an unladen weight of 25,210 kg, leaving only 6,790 kg of payload. Such a high unladen weight relative to gross weight is typical of cryogenic tanks, since the double-walled, vacuum-insulated tank construction for liquid hydrogen at minus 253 degrees Celsius itself contributes substantially to the weight. Width is 2,500 mm, and the permitted top speed is 100 km/h.

Liquid hydrogen must be kept continuously below its boiling point, which is why such semi-trailers are built as cryogenic transporters with their own insulation and safety valves and are not comparable to ordinary tankers for mineral oil products. Class O4 requires an air brake system, and towing requires a category CE licence. Hydrogen transport is additionally subject to dangerous-goods rules for liquefied cryogenic gases.

When buying such a specialised semi-trailer used, the tightness of the tank system and its insulation matters most, and can only be verified by a workshop certified for cryogenic technology. The air brake system, valves and safety devices as well as the condition of axles and wheel bearings belong on the test bench, as does documentation of the tank's recurring pressure tests. Such a trailer is practically only suited to continued use in the same application, since converting a cryogenic tank for other cargo is rarely economical.