Extinguishers that can be carried around in machinery spaces Extinguishers that weigh more than 23 kg, or the maximum mass for a portable extinguisher, are referred to as “non-portable” extinguishers. In general, these are anticipated to be “transportable,” i.e., equipped with wheels, however fixed extinguishers may be acceptable in tight spaces if the rest of this section can be followed. For cargo ship spaces with all of the boilers being for domestic use and being less than 175 kW, 135 litre extinguishers are not necessary. (SC30 of the IACS Unified Interpretation) 6.6.2 Positioning: For cargo ships with fewer spaces, 45-liter foam extinguishers can be placed outside the area in question. (IACS Unified Interpretation SC30 – Interpretation of Regulations 10.5.1 and 10.5.2 in Chapter II-2)