One of our first caravans many years ago, a 2004 Lunar was single axle. On the offside was the fridge, oven and battery and at the rear the double bed. There was nothing under the bed as I was aware of the tail wagging the dog syndrome.
We collected it and set off on our first journey to a campsite with hardly anything in the caravan except a full awning over the axle. The drive felt extremely twitchy, but being reasonable new to caravans thought it was to be expected.
On our next trip out just before Jn 13 on the M5 we overtook an HGV. As we passed the HGV the caravan started to snake. and took us across the 3 lanes. Luckily we were driving a Volvo S80 which had ample weight and power.
Although it was tram lines in the road that probably set off the snake, it probably would not have happened if the appliances inside the caravan had been more evenly distributed. Shortly afterwards even though it was only 6 months old we traded it in for a twin axle as OH felt very apprehensive going out with that caravan.