 They also have less water capacity at in 4x2 form, on 4x4 versions, than a modern vehicle, and poorer stability due to a lack of baffle partitions in the water tank.Some were later modified by the installation of flashing blue lamps and two tone warning sirens, and alterations to the rear lamps, to bring them into line with then current practice on 'regular' emergency appliances.Mechanically, they were designed to be robust and easy to maintain.