I think that the piston speed was the limiting factor, particularly when lubrication was more of a 'hit or miss' affair than it eventually became. If the piston moved too fast and lubrication was poor there was a risk of the piston and cylinder being damaged through metallic contact. But I've no idea what maximum piston speed was considered safe!
I think that the piston speed was the limiting factor, particularly when lubrication was more of a 'hit or miss' affair than it eventually became. If the piston moved too fast and lubrication was poor there was a risk of the piston and cylinder being damaged through metallic contact. But I've no idea what maximum piston speed was considered safe!
Were there actually any speed restrictions on locos pre BR ?
I read somewhere that Fowler 2-6-4 tanks were restricted to 80mph and I have read that 9Fs were supposed to be limited to 50mph, although that was BR, but the 2MTs with the same diameter wheels but shorter cylinder stroke had no such limit and cruised comfortably at 70mph between Preston and Ormskirk.
Bear in mind that before BR there were still limits on speed set by the type of train, so loco designers tended to make locos for handling different types of train at the lowest possible costs, both capital and running.Were there actually any speed restrictions on locos pre BR ? I read somewhere that Fowler 2-6-4 tanks were restricted to 80mph and I have read that 9Fs were supposed to be limited to 50mph,although that was BR, but the 2MTs with the same diameter wheels but shorter cylinder stroke had no such limit and cruised comfortably at 70mph between Preston and Ormskirk.
Were there actually any speed restrictions on locos pre BR ? I read somewhere that Fowler 2-6-4 tanks were restricted to 80mph and I have read that 9Fs were supposed to be limited to 50mph,although that was BR, but the 2MTs with the same diameter wheels but shorter cylinder stroke had no such limit and cruised comfortably at 70mph between Preston and Ormskirk.
Look at post #7 Alex.Didn’t one 9F manage somewhere between 70 - 90mph on an express on one occcasion?