Nitpicker,
I do mean track, ir the distance between wheels on the same axle. Aircraft end is about 3m+ (3 very large paces), the other end has a track of almost 2 m, and a wheelbase of god would be close to 4 m. I dont know what the exact weight is but wopuld estimate in the several hundred kilos. I know that from pushing them around for 5 years. You also have 2 foot brakes that lift the botom step end wheels off the ground to prevent them roling away.
Quite simply, it would take a force 5 cyclone to tople them.
Now, theres allways the chance that these steps (aussie made i believe) have been replaced by cheaper imports thats are not as stable.