Just finished drawing up the Heywood 15" gauge cast iron bolsters as used on the four-wheel bogies on his closed coaches. Springing was provided by rubber blocks set in cast carriers that could travel vertically within the body bolster. First rendering below is the bogie bolster, second is the body bolster and the third is an exploded view of the assembly. Drawings were completed in Autodesk Inventor Pro 2012, renderings run in Keyshot 3 Pro.
(https://www.finescalerr.com/smf/proxy.php?request=http%3A%2F%2Fwww.roughboy.net%2Fimgs%2FHeywoodPassengerBolster%2FHeywoodBogieBolster.jpg&hash=98f92a81c4364914749921810f85e38e474fb4f6)
(https://www.finescalerr.com/smf/proxy.php?request=http%3A%2F%2Fwww.roughboy.net%2Fimgs%2FHeywoodPassengerBolster%2FHeywoodBodyBolster.jpg&hash=8b1a5a15ca4909443a1c777553fbe8393a264d07)
(https://www.finescalerr.com/smf/proxy.php?request=http%3A%2F%2Fwww.roughboy.net%2Fimgs%2FHeywoodPassengerBolster%2FHeywoodBolsterAssy.jpg&hash=d1a08dc9c0830311037570c79b332b4a203c6a10)
Paul