Can someone give me the basic information on this design please? Although I have heard of it, I know nothing about it at all. alan@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx www.alanstepney.info Model Engineering, Steam Engine, and Railway technical pages. MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.