Surge brakes are a type of braking system commonly used on trailers. They work by utilizing the forward momentum of the trailer to activate the brakes when the towing vehicle slows down. This system is particularly useful for maintaining control and stability while towing heavy loads. When the trailer moves forward, a hydraulic actuator is engaged, which applies the brakes on the trailer wheels. This automatic response helps to prevent the trailer from pushing against the towing vehicle, reducing the risk of swaying and improving overall safety during travel.