Pacific and Atlantic Boilers
The wide firebox area for the Pacific class was due to the trailing truck which run underneath the fire grate as opposed to other designs that had the fireboxes between the big rear wheels of the locomotive which creates a lot of problems for the builder to service the ashes and cleaning. The ash pan on a pacific can come out sideways or with a special link on the trailing truck to allow it to fall away at the end of a steam-bay allows easy access for cleaning.

The boilers are made from 10 inch bore pipe, boiler plate and can be a “Briggs” or “Wet Back” type. The tubes are copper, rolled into place, 4.5 inch nominal steam dome, dry steam pipe collected from top of steam dome and distributed to the front tube plate and steam head connection at the rear of the boiler.

The boilers are hydraulically tested and comply the the Boiler code.

The smoke box allows the boiler to slide into it and locked in place and a slider arrangement at the rear allows for boiler expansion.

The Cylinder chest is set at a height relative to the wheel axles, and the ride height is set so the Baker motion gear works according to the design set.

Having a complete locomotive – as in the bones of construction which I have – can strip years off making a 7 1/4 gauge locomotive