Atlantic 3279 wrote: ↑Sat Jun 08, 2019 4:14 pm
Having no idea of what's normal in 5 inch gauge, I'm impressed to see provision for superheating.
superheating is pretty much the norm in 5" and smaller although not every design has it, my 3 1/2 Great Northern for example is superheated but in comparison to 4472 it's just a toy.
For this model, I guess you could say that I'm 'pushing the boat out' a little. Just about everything that works on the full-size loco will also be working on this model although only that that was fitted for my chosen era of 1939.
So, yes it's superheated and the superheater will have a working anti-vacuum valve (as do most live steam models), it's vacuum brakes will be fully operational, monitored with a working duplex gauge, the tender handbrake also works, as do the vacuum connections either end of the loco/tender to connect to carriages with working vacuum brakes. The sanding gear will be just as per full size, leading driver wheels serviced by a gravity sanding box while the middle driver is served with a steam sanding box. Lubrication again will be as per full size, Wakefield Mechanical lubricators, one for the cylinders and the other for the main axles. All axles both loco and tender have their own oil tray's etc as per full size. Cartazzi axle works, motion is all to Gresley design with the required oiling pots etc, etc The backhead will be fully working with no dummy gauges, the only part that I won't do is the carriage heating although there will be a working gauge to show, there will be an awful lot of pipework running between the frames when finished. On the backhead we have the two steam valves, these will be to scale, undecided yet as to whether the clacks will be incorporated in the valve or hidden under the cab floor, this depends on testing. Water gauges will look scale except for the sight glass is slightly higher, I need to be able to see the water level clearly at all times. Two working injectors mounted under the cab as, yes you get it, per full-size..
Then there's the manifold with working steam sanding, blower, ejector, boiler pressure, carriage warming, lubricator warming stop valves. The ashpan dampers will work.. well I think you can get the idea, the list is pretty exhaustive and I've barely touched on it, this is why I still have a good few years before completing the model. In short, this model will hopefully be a true representation of a full size working Gresley A1, both in looks and in how it steams/operates.
Just to bring things up to date, here's the latest picture showing a near completed boiler, not much left to do now, stay ends need cutting off, a good clean in acid and then a pressure test, for this boiler, it will be hydraulically pumped up to 200PSI and held at that for two hours, if she passes that she's ready for many years, perhaps decades of steaming....fingers crossed that the test goes well next week...
cheers
Pete