Excessive force can result in centrifugal stresses that could cause the appliance to move or walk across the floor. Most automatic washers are equipped with an off-balance or out-of-balance switch that stops the washer from spinning and causes a buzzing sound at any point in the cycle when an off-balance condition occurs. On some of the appliances, the master timer knob switch was in series with a single-pole double solenoid.
In the UK it’s very hard to get circuit diagrams or repair manuals. I get many emails from people looking for repair manuals and wiring diagrams for white goods appliances, but they are only available to the trade. Even then they are commonly only available by opening a trade account, paying a subscription and logging online into a manufacturer’s secure technical support web site. Another common way the trade can have access to them is by subscribing to them on DVD, which isn’t cheap, and needs renewing every several months or so. Gone are the days when we used to buy the wiring diagrams and repair manuals in printed form.