The front mounted Coventry Climax 500 gpm pump was very compact and light, helping to balance out weight distribution between the front axle and the added on trailing third axle.vSome of these conversions - with everything loaded on the third axle - were quite unbalanced, resulting in weird handling and ultra light steering!
I think you will find the 4 door versions were worse as the tank was mounted further back due to the extra passengers; these vehicles were to the RAF specification and then someone decides they require more tackle afterwards.
Added by Adrian Carmichael on 03 July 2023.
Adrian. Thanks for the insight. Unfortunately overloading different chassis when adapting them for fire service purposes is by no means limited to Rover products, nor indeed by UK fire services. Some of the worst examples are chassis which have been used for high capacity water tankers, which are not only very often seriously overloaded but also built with a frighteningly high center of gravity. Here on the US, big fire service tankers which carry around 12,500 litres are usually quite carefully constructed, but still represent the vast majority of single vehicle road accidents, despite being a very small proportion of all fire trucks in use.
Added by Rob Johnson on 02 July 2023.