East Sussex Fire & Rescue Service Y87 GNJEast Sussex Fire & Rescue Service
Rear of a Volvo Dual Purpose Flat Bed Lorry Dropping off a Toilet at an Make pumps 5
Y87 GNJ Call Sign Foxtort06 From Newhaven.
This Lorry Also Carries A high quantity of foam specifically for use at major incidents within East Sussex.
Another photo of this Volvo:

Picture added on 08 October 2011 at 17:05
Many countries have rehabilitation units or modules - and of course many of these have toilet facilities. But they are not dedicated to this particular role, and include heating, airconditioning, beverages, light snacks and seating areas as well.
They are also usually turned out only to major incidents. Unless they are very close to the incident, they are very unlikely to attend a five pump fire, which would be attended by around twenty to thirty members and probably require them to be on scene for only a few hours.
Added by Rob Johnson on 27 June 2013.