This is is the Metropolitan Police's catering support unit. The meals-on-wheels brings much needed cuppas to officers attending a prolonged incident. It is, genuinely, called TEAPOT 1. Isn't that marvellous?
This is just one of the many unexpected discoveries in Dave Boulter's book on London's emergency service vehicles. Below, we present a few further highlights. How many have you seen around town?
Many of us are familiar with the conventional Thames River Police launches, but did you know the river police also have these speedy rigid inflatables?
The capital also has a couple of fire boats based in Lambeth. Here's the Fire Dart, sticking two jets of water into the air beside parliament.
The fire service also boasts five Mini Cooper Countryman saloons as nippy fire response units. Here's one doing duty at a public open day.
They're not exactly elegant, but these three-wheeled scooters are the vehicle of choice for Police Community Support Officers.
London's Air Ambulance isn't always available. When it's busy, or grounded, one of these Skodas will bring an advanced trauma team to critical patients.
Some organisations have their own private emergency response teams. Here, for example, is one of the Royal Household's fire vehicles.
And finally... here's a Red Cross buggy, which tends to hang out in the Royal Parks.
London's Emergency Service Vehicles by Dave Boulter is out now from Amberley.