The Swales 3 in 1 with its curb chain and points of attachment for two sets of reins, is a type of Pelham bit.
The top reins are attached to the loose sliding rings that are fitted around the bit’s mouthpiece. A curb chain is attached to the spiral section above the mouthpiece. While it is true to say that the poll pressure is greatly reduced because these inside rings slip around the mouthpiece, it is also important to acknowledge that they will have the ability to intensify the bit’s action by squeezing inwards upon the sides of lips and mouth.
Additionally, there will be a strong downwards action across the mouth as well as pressure upon the chin groove via the curb chain. If a Swales 3 in 1 was fitted with a jointed mouthpiece the action across the horse’s jaw would be very severe.
This bit is used on horses that are prone to being very strong by leaning on the rider’s hand or snatching at the bit.
The Swales 3 in 1 bit has been available since the early 1900s but had been little seen since the 1980s. More recently it has become increasingly popular being used with some show horses and show jumpers. As a strong bit it is best used in the hands of skilled, empathetic and experienced riders’.